Embed Size (px)
Citation preview
Biologiske Meddelelserudgivet af ^
Det Kongelige Danske Videnskabernes Selskab Bind 23, nr. 12
Biol. Medd. Dan. Vid. Selsk. 23, no. 12 (1963)
NOTES ONHYOLITHELLUS BILLINGS, 1871,
CLASS POGONOPHORA JOHANNSON, 1937
BY
VALDEMAR POULSEN
København 1963 kommission hos Ejnar Munksgaard
Det Kongeuge Danske Videnskabernes Selskab udgiver følgende publikationsrækker: mMm. "
The Royal Danish Academy of Sciences and L etters issues the following series o f publications:
Oversigt over Selskabets Virksomhed (8*) (Annual in Danish)
Historisk-fliosoliske Meddelelser (8**) Historisk-filosoflske Skrifter (4®)
(Historyt Philology, Philosophy, Archeology, Art History)
Matematisk-fysiske Meddelelser (8®) Matematisk-fysiske Skrifter (4®)
(Mathematics, Physics, Chemistry, Astronomy, Geology)
Biologiske Meddelelser (8®)Biologiske Skrifter (4®)
(Botany, Zoology, General Biology)
Bibliographical Abbreoiaiion
Overs. Dan. Vid. Selsk.
Hist. Filos. Medd. Dan. Vid. Selsk. Hist. Filos. Skr. Dan. Vid. Selsk.
Mat. Fys. Medd. Dan. Vid. Selsk. Mat. Fys. Skr. Dan. Vid. Selsk.
Biol. Medd. Dan. Vid. Selsk. Biol. Skr. Dan. Vid. Selsk.
Selskabets sekretariat og postadresse: Dantes Plads 5, København V.
The address of the secretariate of the Academy is:Det Kongelige Danske Videnskabernes Selskab, '
Dantes Plads 6, Kdbenhaon V, Denmark.
Selskabets kommissionær: E jn a r Munksoaard ' s Forlag, Nørregade 6,København K.
The publications are sold by the agent of the Academy:E jn a r Munksoaard , Publishers,
6 Ndrregade, Kdbenhaon K , Denmark.
Biologiske Meddelelserudgivet af
Det Kongelige Danske Videnskabernes Selskab Bind 23, nr. 12
Biol. Medd. Dan. Vid. Selsk. 23, no. 12 (1963)
NOTES ONHYOLITHELLUS BILLINGS, 1871,
CLASS POGONOPHORA JOHANNSON, 1937
BY
VALDEMAR POULSEN
København 1963i kommission hos Ejnar Munksgaard
SynopsisThe genus Hyolithellus B il l in g s , 1871 is discussed, and it is demonstrated
that the much disputed “operculum” (Discinella H a l l , 1871) must be excluded from Hyolithellus. The “operculum” has possibly monoplacophoran affinity. Evidence indicates that Hyolithellus may well be referred to the class Pogonophora JoHANNsoN, 1937. The structure of the tubular skeleton in members of the Pogonophora is strikingly similar to that of Hyolithellus. X-ray fluorescence analysis of the tubes apparently also confirms the pogonophoran relationship and the exclusion of Discinella and its allies from Hyolithellus. Considering the early appearance of representatives of the Hemichordata (Lower Ordovician), it does not seem unreasonable to regard the Lower- and Middle Cambrian Hyolithellus as a close relative of the Hemichordata.
Printed in Denmark Bianco Lunos Bogtrykkeri A-S
Introduction
Classification of several C am brian an im al groups presents m any difficulties. Hyolithellus has lately ( F i s h e r , 1962) been re
ferred to an order H yolithelm inthes, the affinities of w hich su p posedly are quite unknow n. At presen t the au thor is studying a Lower C am brian fauna from the island of B ornholm containing num erous specim ens of Hyolithellus. A revision of this genus has long been needed on account of the error m ade by m any authors, in assigning an opercu lum to it. As will be shown, the “ opercu lum ” was correctly established as a m olluscan genus by H a l l , 1871.
Mr. J. B. K ir k e g a a r d , M. Sc., of the Zoological M useum of the University of Copenhagen, called the au th o r’s attention to certain hem ichordate relatives, class Pogonophora, the m em bers of w hich mostly belong to the benthonic environm ent of the deep sea. Their tu b u la r skeleton bears m uch resem blance to H yolithellus tubes. Mr. K ir k e g a a r d kindly p laced a specim en of the tube of Galathealinum bruuni at the au th o r’s d isposal for study.
!♦
* \3
f i
Class P O G O N O P H O R A J o h a n n s o n , 1937
O rder HYOLITHELLIDA S y s s o ie v , 1957, (p artim )
Fam ily H y o l it h e l l i d a e W a l c o t t , 1886, (p artim )
Genus H y o l i t h e l lu s B i l l i n g s , 1871
Type species: Hyolithes micans B il l in g s
The type species is the m ost w idely d istribu ted of the species referred to Hyolithellus, and the discussion m ainly concerns this species.
T h e “ o p e r c u l u m ” : B il l in g s (1871), w hen describing H yolithellus, assigned an operculum to the tu b u la r fossil, bo th occurring in the Low er C am brian of Troy, New York. F rom the sam e beds H all described specim ens of Discinella. His p ap e r should have been published in 1871, bu t the whole edition was destroyed by fire, an d his results were not pub lished un til 1873. In any case. H a l l as the first differentiated Discinella u n d er a special nam e. He concluded that, on account of the peculiar m uscle scars, the fossil could hard ly be recognized as a brachio- pod, bu t ra th er as a gastropod. The general charac ter of the shell, he fu rther concluded, is such as to ally it w ith the Discinidae, and , accordingly, the nam e Discinella was proposed. W a lc o tt (1886, p. 142) called attention to the fact th a t the supposed operculum of Hyolithellus was the sam e form , as the one called Discinella by H a l l . Since then, p ractically all A m erican p a leontologists have followed B il l in g s and W a lc o tt in regarding Discinella as the operculum of Hyolithellus. In this connection it m ust be noted th a t they usually occur in the sam e beds. K night and Y o c h e l s o n (1960, p. 324) rejected Hyolithellus an d its “ opercu lum ” from the G astropoda an d M onoplacophora. F i s h e r
6 Nr. 12
(1962) regarded Barella, Discinella, and Mobergella as hyolithel- m in th opercula.
M o b e r g (1892) pointed out that in Swedish sedim ents, in w hich Discinella m ay cover alm ost entire bedding planes, no tu b u la r fossils to m atch the “ opercu la” are found. At the sam e tim e Discinella is absent in beds rich in tu b u la r fossils.
H olm (1893), w hen discussing the H yolithidae refused to re cognize any re lationship between Hyolithes an d Hyolithellus. W ith regard to Hyothellus he stated th a t the tube w as difficult to assign to any class, and the “ opercu lum ” should be rem oved from the genus.
H e d s t r o m (1923), after including Discinella in a new genus, Mobergella, referred the univalve fossil to the G astropoda, as a lready tentatively suggested by H a l l . In 1930 H e d s t r o m re alized th a t the nam e Discinella could not be suppressed, as the action was contrary to the rules of in ternational zoological nom enclature. On the other h an d , a differential analysis show ed that im portan t differences in n um ber and arrangem ent of the m uscle scars occur, and , accordingly, H e d s t r o m concluded th a t the nam e Mobergella m ight be applied to specim ens, w hich differ clearly from Discinella.
C. PouLSEN (1932) described Hyolithellus micans and Discinella micans from the Lower C am brian of East G reenland. He referred Discinella to the fam ily Patellidae. P o u l s e n ’s m ateria l clearly dem onstrates that a d isparity exists w ith regard to the diam eter of the specim ens of Discinella an d that of the tu b u la r Hyolithellus shells. The diam eter of Discinella is up to twice the d iam eter of the tubes. The sam e disparity is quite evident in specim ens figured by L ocum an (1956). In the au th o r’s opinion an eventual opercu lum should be expected to fit in wdth the tubes or to be slightly sm aller.
CoBBOLD, w^ho in several papers described occurrences of Hyolithellus in England, never found an operculum , w hich could be assigned to the genus. In Sweden the “ opercu la” and the tubes occur at definitely separate levels. The au tho r m ay add th a t Hyolithellus micans occurs abundan tly in a M iddle C am brian clay on the island of Bornholm. In this deposit Discinella and Mobergella are totally absent. The absence canno t be explained as an effect of separation during transporta tion , as the hyolithellid
Nr. 12 7
tubes in the clay are associated w ith thousands of inarticulate b rachiopod shells, w hich from point of view of transporta tion dynam ics are very sim ilar to the shell of Discinella.
The au thor believes that the above m entioned objections clearly dem onstrate th a t the “ opercu lum ” of Hyolithellus m ust be excluded from the genus. At the sam e tim e the m uscle scars seen in Discinella, Mohergella, and Barella in some respects are very sim ilar to those found in the M onoplacophora (text fig. 1 d). In the Lower C am brian faunas only m em bers of the order T ryblid ioidea bear any resem blance to Discinella and its allies, w hich possibly should be regarded as close relatives of the M onoplacophora.
P rev io u s c la ss ifica tio n of H yo lith e llu s
Since B il l in g s established Hyolithellus in 1871, the genus has been assigned to various classes and phyla. Originally Hyolithellus was believed to be closely related to Hyolithes, and n a tu ra lly the presence of a hyolithellid operculum was essential in this connection.
As late as in 1959 S y s s o ie v grouped the o rder H yolithellida (com prising Hyolithellus, Coleoloides, an d Coleolus) an d the order H yolithida in a superorder H yolithoidea of the phylum M ollusca.
Also a relationsh ip to some w orm phylum like the phoronids has been suggested, an d this view point is favoured by several paleontologists. F is h e r (1962) established an order Hyolithel- m inthes, com prising the fam ilies Hyolithellidae an d Torellellidae. He cautiously regarded class an d phylum as uncertain , bu t the entoproctid or phoron id relationship was suggested on account of the phosphatic shell com position.
As m entioned earlier the au th o r’s attention has been called to the class Pogonophora, the tubes of w hich strikingly resem ble th a t of Hyolithellus. The resem blance even included the concentrations in the tubes of certain elem ents.
H yo lith e llu s and c la ss P ogon op h ora J o h a n n s o n , 1937
T he following analysis of structures in Hyolithellus an d the Pogonophora is based m ainly on specim ens of Hyolithellus micans, obtained by élutriation of a M iddle C am brian clay from the island
8 Nr. 12
of B ornholm , and on a 30 centim etres long tube of the pogono- phore Galathealinum bruuni K ir k e g a a r d , kindly furn ished by Mr. J . B. K i r k e g a a r d .
T u b u l a r s t r u c t u r e : It is a characteristic feature in Hyolithellus th a t the tu b u la r shell is curved an d irregular near the ap ical end bu t straightening tow ard the aperture. The growth angle in the adu lt section varies from one to four degrees. The cross section is c ircular, an d the d iam eter m ay rise to abou t three m illim etres.
This description also perfectly covers Galathealinum.T ubes of Hyolithellus show characteristic surface m arkings
consisting of an irregular annu lation and transverse striation, considered to be growth lines. The annulations an d striae are usually dim inutive, bu t irregularly spaced, coarser m arkings occur, possibly indicating m ajor changes of growth conditions (text fig. lb ) . In terior surface of tube is sm ooth, devoid of septa or any other structure. The tube is th in-w alled at the apical end, bu t thickens progressively tow ard the apertu re (text fig. 1 c).
Galathealinum has the sam e type of surface m arkings (text fig. 1 a), a sim ilar sm ooth in terior surface, and a g radual th ick ening of the tube w all is also seen. C haracteristic in the pogono- phore are one to two centim etres long, irregularly spaced sections, in w hich the annu lation is particu larly coarse. In the dried specim en of Galathealinum the transverse m arkings on the su rface presen t points of w eakness, at w hich the tube easily breaks. A part from this, brittle and m ore soft sections of the tube evidently alternate, at least in som e pogonophores. S im ilar points of w eakness are p robab ly also present in Hyolithellus, an d this m ay explain, w hy the fossil fragm ents rarely exceed five centim etres in length. Fragm ents of Hyolithellus w ith unusually coarse a n n u lation on the surface have been recorded (W alcott, 1890, and L ochman, 1956). W alcott thus recognized a variety, H. micans rugosa, based on a single tube, w hich shows coarse transverse ridges and striae, betw een w hich are fine longitudinal striae. S im ilar specim ens collected by L ochman show no trace of longitud inal striae, and she was re luc tan t to refer these specim ens to W alcott’s variety, or to describe them as a new subspecies. The present w riter believes th a t the coarsely annu lated hyolithellid fragm ents m ay well correspond to the likewise coarsely annu lated sections in Galathealinum.
Nr. 12 9
L ochman (1956) reported th a t some th in tu b u la r fragm ents of Hyolithellus show a scattering of oval holes or pores through the lam ina of the tube wall. She suggested th a t this is p robab ly the structure of each ind iv idual layer, bu t superposition of layers in com plete tubes gives the appearance norm ally observed. Despite careful study of the beautifu lly preserved hyolithellid fragm ents from B ornholm the au thor has not been able to find a sim ilar porous structure, and he believes that the pores m ay possibly be due to im perfect state of preservation, or eventually a resu lt of the m ethod of p repara tion by etching w ith acetic acid. N atural pores are not seen in the specim en of Galathealinum, bu t a slightly dam aged section of the tube shows m echanically p ro duced holes th rough the outer lam ina.
hi
JFig. 1. a: Growth lines on tube-fragment of Galathealinum bruuni K ir k e g a a r d (2 x); b: Grow'th lines on tube-fragment of Hyolithellus micans B il l in g s (2 x); c: Hyolithellus, longitudinal section, showing progressive thickening of the tube wall (2 x); d: Mobergella holsti (M o b e r g ), ventral view, showing muscle scars (4 x).
T h e t u b u l a r s u b s t a n c e : The tube of Hyolithellus is com posed of m any fine lam inae, added progressively layer by layer. The th in apical p art of the tube thus contains only a few layers. Exactly the sam e structure is found in Galathealinum.
Mr. I b S ø r e n s e n , cand. polyt., of the Geological Institute of the U niversity of Copenhagen, k indly m ade X -ray fluorescence analysis on specim ens of Hyolithellus and the tube of Galathealinum. Considering the rem ark ab le results (tab le 1, p. 12), a
10 Nr. 12
sim ilar analysis of specim ens of Mobergella was im perative. In o rder to differentiate the influence of diagenesis in the fossils in the deposit, several specim ens of the associated b rach iopod : Acrotreta socialis were analysed.
The specim ens of Hyolithellus and Acrotreta w ere collected from the unconsolidated M iddle C am brian clay on the island of Bornholm . Evidently, the deposit, ap a rt from precipitation of som e pyrite, can only have been im perceptib ly affected by dia- genetic processes, and , accordingly, m uch of the original shell structure of the fossils is preserved. The specim ens of Mobergella holsti originate from a sam ple of pure. Low er C am brian san d stone from the island of Ö land.
The tubes of Hyolithellus consist m ainly of an organic su b stance and some C alcium carbonate. X -ray analysis shows that no phosphorus is present. A control analysis of a m inim al am ount of pure phosphate indicates that even extrem ely poor concen trations or traces of phosphorus will show up. The absence of this elem ent is m ost unexpected. The specim ens of Acrotreta and in ternal m olds of hyolithellid tubes from the sam e deposit show a “ n o rm al” concentration of phosphorus. These conditions have caused the au thor to believe that the phosphate found in hyolithellid tubes from deposits elsew here is m ainly secondary, having rep laced the Calcium carbonate, and p robab ly to some extent dependan t upon the phosphorus originally contained in the soft parts of the anim al, and now preserved in the in ternal m olds of the tubes. The replacem ent of Calcium carbonate by phosphatic m aterial is a com m on phenom enon in sedim ents.
Most p robab ly the tube of Hyolithellus consists p rim arily of thin lam inae of organic substance, separated by fdms of calc ium carbonate. Such texture is found in the pogonophore Galathea- liniim. The X -ray fluorescence analysis of the pogonophore shows a relatively high content of calcium , bu t no phosphorus. According to I vanov (1960, p. 93), the organic substance of the pogonophore tubes is a polysaccharid (tunicin). It is com m only believed that the organic substance in Hyolithellus is chitinous, bu t this cannot be ascertained.
The distribution of other elem ents needs some com m ents. Galathealinum contains a sm all am ount of vanad ium , iron, and m anganese. In the three fossil genera analysed, vanad ium is
Nr. 12 11
absent, an d they fu rther differ in containing titan ium and chrom ium , w hich are absent in the pogonophore. These elem ents originate supposedly from precipitation of m ostly iron-rich solutions. In the Middle C am brian clay from Bornholm , containing Hyolithellus an d Acrotreta, the iron is accom panied by a notable am ount of m anganese. The sedim ent is seen to contain som e pyrite, w hich also to som e extent has affected the fossils, as some of these show a brow nish stain or coating originating from iron.
Cerium , w hich is absent in Galathealinum, accom panied ca lcium , and partly substituted this elem ent, w hen subsequently precipitated in the fossils. Cerium m ay have been present in Mobergella and Acrotreta, bu t absent in Hyolithellus, w hen the anim als were alive.
After buria l, the tubes of Hyolithellus and the shells of Acrotreta an d Mobergella were fu rther enriched in potassium and silicium . At the sam e tim e the eventual am ounts of iodine and su lphur were carried aw ay in solution. V anadium m ay, or m ay not, have been present originally, only to be substitu ted by chrom ium an d titanium .
Hyolithellus and Galathealinum are both distinguished by the rich concentration of zinc, w hich is only very poorly represented in Mobergella and Acrotreta. In the last m entioned genera the poor concentration supposedly balances w ith the average concentration of this elem ent in the sea w ater, w hen the anim als were alive. The pogonophore is rich in nickel, and also H yolithellus contains a surp lus of this elem ent, as com pared to Mobergella an d Acrotreta. F inally, the hyolithellid tube and the pogonophore tube are distinguished by the absence of phosphorus, an d deficiency, respectively absence of cerium . In the present w riter s opinion the chem ical sim ilarities, pointed out above, support the proposed pogonophoran affinity of Hyolithellus.
The X-ray analysis also serves to show that Mobergella and its allies, p robab ly p rim arily phosphatic, are to be regarded as distinct genera, w hich cannot be referred to as byolithellid opérenla.
The shell m aterial of Mobergella differs from th a t of H yolithellus in the content of calc ium phosphate, the surp lus of cerium , the p ronounced deficiency of zinc, and the som ew hat sm aller content of nickel.
12 Nr. 12
T able 1. C oncentrations of elem ents in the specim ens of Gala- thealinum , Hyolithellus, Mobergella, an d Acrotreta as registered
by X-ray fluorescence analysis.
Galathealinum Hyolithellus Mobergella Acrotreta
Ca l c i u m .......... + + + + + + + + + + + "f + +Ce r i u m ............ - + + + +Ch r o m iu m . . . . H- + + + +I o d in e ............... + + -Í- 4-Ir o n .................... + + + + + + + + + + + +Ma n g a n e s e . . -h + + + + + + + -f-N ic k e l ............ + + + + + + + + + ++P h o s p h o r u s . . H- + + ++P o ta ssiu m . . . H- + + ++S i l i c i u m .......... + + +Su l p h u r .......... + + 4.
T it a n iu m . . . . + + + + ++V a n a d iu m . . . . + + -Í- 4.
Z i n c .................... + + + + + + + + +Relative concentrations indicated by following symbols: = absent, + =
traces or very poor, ++ = poor, + + + = moderate, + + + + = rich. The symbols are only valid for intergeneric comparison. No quantitative distinction between the individual elements is implied.
S u m m a r y o f c o n c l u s i o n s : The occurrence on the island of B ornholm of num erous specim ens of Hyolithellus in a deposit devoid of discinelloid form s, and the Scanian occurrence of Mobergella at stratig raphical levels, definitely separate from levels contain ing Hyolithellus an d Torellella, indicates th a t Mobergella an d its allies canno t be regarded as hyolithellid opérenla. Also the d isparity w ith regard to the diam eters of tubes an d “ opéren la” , an d dilTerences in concentrations of elem ents in the shells an d tubes su pport a separation.
The genera Discinella, Mobergella, an d Bar ella w ith regard to pattern of m uscle scars show affinities to the M onoplacophora.
In Hyolithellus the entire tu b u la r structure is identical to that of recent m em bers of class Pogonophora, w hich is closely related to the hem ichordates. Also the texture of the hyolithellid tube is identical to th a t of the pogonophore tube. Tbe sim ilarity is further
Nr. 12 13
accentuated by the concentrations of zinc and nickel. In both groups the tubes are believed to consist m ainly of organic su b stance in th in lam inae separated by films of C alcium carbonate. The available evidence thus favours the reference of Hyolithellus to the Pogonophora.
The class Pogonophora is divided into two o rders: Atheca- nep h ria Ivanov , 1955 an d T hecanephria Ivanov , 1955. The orders are classified by differences in the anatom y of the soft parts, and , accordingly, the position of the hyolithellids w ithin the class is open to discussion. The present w riter tentatively suggests th a t a th ird o rder: Hyolithellida, com prising the families H yolithellidae W alcott , 1886 (p a rtim ) an d Torellellidae H olm , 1893, m ay be added to the class.
B io lo g y of the H yo lith e llid a
It is indeed interesting th a t the class Pogonophora originated in the Low er C am brian an d has been able to persist up to the presen t day. Several paleontologists believe that fau n a elem ents living in the deep sea or on the abyssal p a rt of the continental slope m ay obtain a geologically long life owing to the supposed stable ecology of these habitats. If representatives of an im al groups only know n as fossils are to be found, they will m ost likely be inhab itan ts of the abyssal regions, an d evidence at h an d shows th a t these regions do contain relicts. During the D anish Galathea Deep Sea Expedition 1950-1952 the m onoplacophore Neopilina L emche was found, an d this genus belongs to the order T ryblid ioidea, w hich was form erly regarded as a Paleozoic group (C am brian — Devonian). Also the P terobranch ia (O rdovician- Recent) m ay be m entioned. The au tho r regards the class Pogonoph o ra as ano ther exam ple. Possibly m ore relicts are waiting for discovery, an d in fu ture w ork special attention should be directed to the abyssal p a r t of the continental slope.
The m ajority of the pogonophore species are found betw een 1500 an d 10000 m etres of depth, bu t species of Siboglinum are know n to range into littoral waters. As the pogonophores are obtained by dredging, m ostly at abyssal depths, not too m uch is know n of their habits. They are assuredly benthonic, leading a sedentary life in the bottom ooze, never leaving their tubes,
14 Nr. 12
w hich apparen tly have an upright position, w ith the irregularly curved apical end bu ried in the ooze. T he larva l developm ent is know n only in a few species. In these the eggs are hatched in the fem ale tube in the section close to the apertu re, and also the larval developm ent takes place in the tubes. The larva p robab ly only leads a b rie f free existence, before starting the build ing of the tube.
The hyolithellids occur in practically all types of sedim ents, b u t are not too com m on in sandstones or siltstones, unless they are argillaceous, an d they are very ra re in dolom ites an d gray- w ackes. L ike the pogonophores the hyolithellid tubes were m ost likely anchored in an upright position w ith the apical end buried in the soft bottom . The uncom m only wide d istribution of Hyoli- thellus has been explained by the wide tolerance as to facies, an d fu rtherm ore a p lanktonic larval developm ent has been suggested. The present w riter is of the opinion th a t a tolerance also of depth m ay be assum ed, an d pathw ays of m igration m ay have crossed depths, w hich w ould present unsurm ountab le obstacles to the com m on shallow w ater fauna.
The hyolithellids m ay be regarded as the scarce shallow w ater representatives of the C am brian pogonophores, p redom inantly occupying the abyssal regions, w hich are not represented in the sed im entary record. As stated by L ochm an , the natu re of Hyolithellus is such that several species m ay be present, bu t a differentiation has not yet been possible.
Considering the fact th a t other groups w ith hem ichordate affinity (P terob ranch ia) appeared in the early O rdovician, the occurrence of Pogonophora in the C am brian m ust be regarded as very probable.
Geological Institute of the University of Copenhagen
Nr. 12 15
R eferences
B il l in g s , E. 1872: On some new genus of Paleozoic fossils. Canadian Naturalist, vol. 6.
F is h e r , D.W. 1962: Small conoidal shells of uncertain affinities. In: Treatise on invertebrate paleontology, part W. Univ. Kansas Press.
H a l l , J. 1873: On some new or imperfectly known forms among the Brachiopoda. 23. Ann. Rep. New York State Mus. Nat. Hist.
H e d s t r o m , H. 1923: On “Discinella holsti Mb g .” and Scapha antiquis- sima (M a r k l .) of the division Patellacea. Sveriges Geol. Undersok- ning, ser. C, no. 313.
— 1930: Mobergella versus Discinella. Paterella versus Scapha & Archæophiala. Sveriges Geol. Undersdkning, ser. C, no. 362.
H o lm , G. 1893: Sveriges Kambrisk-Siluriska Hyolithidae och Conu- lariidae. Sveriges Geol. Undersdkning, ser. C, no. 112.
H y m a n , L. H . 1959: Smaller coelomate groups. In: The Invertebrates, vol. 5. McGRAW-HILL Book Company, Inc.
Iv a n o v , A. V. 1960: Pogonophora (Fauna SSSR). (In Russian). Akademii Nauk SSSR, new ser., no. 75.
K n ig h t , J. B. & Y o c h e l s o n , E. L. 1960: Monoplacophora. In: Treatise on invertebrate paleontology, part I. Univ. Kansas Press.
L o c h m a n , C. 1956: Stratigraphy, paleontology, and paleogeography of the EUiptocephala asaphoid.es strata in Cambridge and Hoosick quadrangles. New York. Bull. Geol. Soc. America, vol. 67.
M o r e r g , J. G. 1892: Om en nyupptackt fauna i block af kambrisk sandsten, insamlade af dr. N. O. H o l st . Sveriges Geol. Undersdkning, ser. C, no. 125.
P o u l s e n , C. 1932: The Lower Cambrian faunas of East Greenland. Medd. om Grønland, vol. 87, no. 6.
W a l c o t t , C. D. 1886: The Cambrian faunas of North America. Bull. U.S. Geol. Survey, no. 30.
Z e n k e v it c h , L. a . 1954: Erforschungen der Tiefseefauna im Nordwestlichen Teil des Stillen Ozeans. In: The Deep Sea bottom fauna. Int. Un. Biol. Sciences, ser. B, no. 16.
Indleveret til Selskabet den 12. februar 1963. Færdig fra trykkeriet den 31. maj 1963.
I ,*r .
- 4
I
'ï ■
5;^
¥'.■.jêr
{,
M■ViS,
'S»
•- Jk^--’ • x
Sbù>i T.'
Det Kongelige Danske Videnskabernes Selskab Biologiske Meddelelser
(Biol. Medd, Dan. Vid. Selsk.)
Bind 22 (kr. 65,00) kr.ø.1. Jensen, P. Boysen: Untersuchungen über Determination und
Differenzierung. 2. Über die Wachstumsvorgänge in der Spitze der Wurzelhaare von Phleum. With an English Summary. 1954 3,50
2. Böving, Adam G.: Mature Larvae of the Beetle-Family Ano-biidae. 1954........................................................................................ 35,00
3. Gamow, G.: Possible Mathematical Relation between Deoxyribonucleic Acid and Proteins. 1954........................................... 2,00
4. Børgesen, F.: Some Marine Algae from Mauritius. Additionsto the Parts Previously Published. VI. 1954 ............................ 8,00
5. Jensen, P. Boysen: Untersuchungen über Determination undDifferenzierung. 3. Über die Wirkungsweise des determinierenden Faktors, der bei der Bildung der Wurzelhaare von Lepidium, Sinapis und Phleum tätig ist. With an English Summary. 1955..................... 4,50
6. Salomonsen, Finn: The Evolutionary Significance of Bird-Migration. 1955.................................................................................. 6,00
7. Münch-Petersen, Agnete, Kalckar, Herman M., and Smith,Evelyn E. B.: Uridyl Transferases, their Occurrence and Physiological Role. 1955 ................................................................ 3,00
8. Gamow, G.: On Information Transfer from Nucleic Acids toProteins. 1955.................................................................................... 1,00
9. Hevesy, G.: Conservation of Skeletal Calcium Atoms throughLife. 1955 ............................................................................................ 2,00
Bind 23(jiafsluttet!in preparatioii)
1. Rasmussen, Erik: Faunistic and Biological Notes on MarineInvertebrates III. The Reproduction and Larval Development of some Polychaetes from the Isefjord, with some Faunistic Notes. 1956 ........................................................................................ 11,00
2. Petersen, Johs. Boye, and Hansen, J. Benth: On the Scalesof some Synura Species. 1956 ..................................................... 7,00
3. Brøndsted, H. V.: Experiments on the Time-Graded Regeneration Field in Planarians. With a Discussion of its Morphogenetic Significance. 1956 .............................................................. 7,00
4. Børgesen, F.c Some Marine Algae from Mauritius. Final PartEdited by Tyge Christensen. 1957 ............................................ 5,00
5. Jensen, P. Boysen: Untersuchungen über Determination und kr. ø.Differenzierung. 4. Über den Aufbau des Zellwandgerüstes der Pflanzen und die Determination desselben. With an English Summary. 1957......................................................................... 6,00
6. Larsen, Kai: Cytological and Experimental Studies on theGenus Erodium with Special References to the Collective Species E. Cicutarium (L.) L’Her. 1958 ....................................... 4,00
7. Petersen, Jobs. Boye, and Hansen, J. Benth: On the Scalesof some Synura Species. II. 1958 ................................................ 3,50
8. Jensen, P. Boysen: Untersuchungen über Determination undDifferenzierung. 5. Über die Wirkungsweise des Wuchsstoffes in dem Epikotyl von Phaseolus (Die Brückentheorie der Wuchsstoffwirkung). With an English Summary. 1958 ....... 7,00
9. Golomb, S. W., Welch, L. R., and Delbrück, M.: Constructionand Properties of Comma-Free Codes. 1958 ............................ 5,(X)
10. Jensen, P. Boysen: Untersuchungen über Determination undDifferenzierung. 6. Über den Aufbau des Zellwandmusters des Blattes von Helodea densa. With an English Summary. 1959 5,00
11. Nielsen, Erik Tetens: On the Habits of the Migratory Butterfly Ascia monusle L. 1961......................................................... 12,00
12. Poulsen, Valdemar: Notes on Hyoliihellus Billings, 1871, ClassPogonophora Johannson, 1937. 1963............................................ 2,50
On direct application to the agent of the Academy, E jn a r M u n k s- GAARD, Publishers, 6 Norregade, Kobenhavn K., a subscription may be taken out for the series of Biologiske Meddelelser. This subscription automatically includes the Biologiske Skrifler in 4to as well, since the Meddelelser and the Skrifter differ only in size, not in subject matter. Papers with large formulae, tables, plates etc., will as a rule be published in the Skrifter, in 4to.
For subscribers or others who wish to receive only those publications which deal with a single group of subjects, a special arrangement may be made with the agent of the Academy to obtain the published papers included under one or more of the following heads: Botany, Zoology, General Biology.
In order to simplify library cataloguing and reference work, these publications will appear without any special designation as to subject. On the cover of each, however, there will appear a list of the most recent papers dealing with the same subject.
The last published numbers of Biologiske Meddelelser within the group of General Biology are the following:
Vol. 28, nos. 9, 12.
Printed in Denmark. Bianco Lunos Bogtrykkeri A/S
Id: 262Forfatter: Poulsen, ValdemarTitel: Notes on Hyolithellus Billings, 1871, Class Pogonophora Johanneson, 1937.År: 1963ISBN:Serietitel: Biologiske Meddelelser Serienr: B 23:12 SerienrFork: B Sprogkode: Eng
