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1 


ZOOLOGY  LIBRARY 


51d3-7 


University  of  the  State  of  New  York 


New  York  State  Museum 


John  M.  Clarke  State  Paleontologist 


Memoir  7 

GRAPTOLITES  OF  NEW  YORK 

Part  1 

GRAPTOLITES  OF  THE  LOWER  BEDS 


BY 

RUDOLF  RUEDEMANN 

*  ft 


PAGE 


Preface . 457 

Introduction . . .  459 

References .  459 

History  of  the  study  of  graptolites  .  466 
Methods  of  investigation  and  illustra¬ 
tion  .  479 

Terminology .  482 


Range  and  geographic  distribution.  488 
Correlation  table  of  zones  faces . .  490 
Synoptic  table  of  distribution  of 


species .  504 

Synoptic  table  of  range  of  genera  508 

Mode  of  existence .  509 

Mode  of  reproduction  and  ontogeny  519 
Structure  and  morphology .  534 


PAGE 

Histology  and  chemical  composition 


of  the  periderm .  539 

Classification  and  phylogeny  of  the 

graptolites . 543 

Synoptic  list  of  fossils  described. .  572 
Taxonomic  relations  of  the  grapto¬ 
lites  . 574 

Descriptions  of  graptolites .  578 

Dendroidea .  578 

Graptoloidea .  612 

Axonolipa . 612 

Axonophora . 718 

Addendum .  735 

Explanations  of  plates. . .  743 

Index .  785 


ALBANY 

NEW  YORK  STATE  EDUCATION  DEPARTMENT 

1904 


\ 

STATE  OP  SEW  YORK 

EDUCATION  DEPARTMENT 

Regents  of  the  University 

With  years  when  terms  expire 

1913  "Whited aw  Reid  M.A.  LL.D.  Chancellor . New  York 

1906  St  Glair  McKelway  M.A.  L.II.D.  LL.D.  D.C.L. 

Vice  Chancellor  Brooklyn 

1908  Daniel  Beacii  Pli.D.  LL.D. . Watkins 

1914  Pliny  T.  Sexton  LL.D. . Palmyra 

1912  T.  Guilford  Smith  M.A.  C.E.  LL.D. . Buffalo 

1905  Albert  Vander  Veer  M.D.  M.A.  Pli.D.  LL.D.  ....  Albany 

1907  William  Nottingham  M.A.  Pli.D.  LL.D. . Syracuse 

1910  Charles  A.  Gardiner  Pli.D.  L.H.D.  LL.D.  D.C.L  -  -  -  New  York 

1915  Charles  S.  Francis  B.S. . -  -  -  Troy 

1911  Edward  Lauterbach  M.A. . New  York 

1909  Eugene  A.  Piiilbin  LL.B.  LL.D. . New  York 

Commissioner  of  Education 

Andrew  S.  Draper  LL.D 
Assistant  Commissioners 

Howard  J.  Rogers  M.A.  LL.D.  First  Assistant  Commissioner 
Edward  J.  Goodwin  Lit.  D.  Second  Assistant  Commissioner 
Augustus  S.  Downing  M.A.  Third  Assistant  Commissioner 

Secretary  to  the  Commissioner 
Harlan  H.  Horner  B.A. 

Director  of  Libraries  and  Home  Education 
Melyll  Dewey  LL.D. 

Director  of  Science  and  State  Museum 

John  M.  Clarke  LL.D. 

Chiefs  of  Divisions 

Accounts,  William  Mason 
Attendance,  James  D.  Sullivan 
Examinations,  Charles  F.  Wheelock  B.S. 

Inspections,  Frank  H.  Wood  M.A. 

Law,  Thomas  E.  Finegan  M.A. 

Records,  Charles  E.  Fitch  L.H.D. 

Statistics,  Hiram  C.  Case 


PREFACE 


The  preparation  of  this  memoir  is  the  outcome  of  stratigraphic  investiga¬ 
tions  carried  on  for  several  years  in  the  slate  belt  of  eastern  New  York.  The 
discovery  of  graptolite  zones  affording  rich  and  well  preserved  faunas  new 
to  the  New  York  series  of  geologic  formations,  has  made  us  acquainted 
with  graptolite  facies  of  the  important  formations  represented  in  the  time 
interval  from  the  Upper  Cambric  to  the  end  of  the  Lower  Siluric.  The 
important  bearing  which  the  distribution,  correct  correlation  and  identifica¬ 
tion  of  these  graptolite  faunas  have  on  the  geologic  history  of  New  York 
in  earlier  Paleozoic  time,  and  on  Paleozoic  paleography  in  general,  demands 
their  monographic  treatment,  with  special  reference  to  range  and  geographic 
distribution. 

On  account  of  the  very  large  amount  of  material  to  be  considered, 
it  has  been  deemed  advisable  to  divide  this  treatise  in  two  parts,  of 
which  this  is  the  first.  It  contains  the  descriptions  of  the  graptolites 
of  the  Upper  Cambric  and  Lower  Champlainic  (Lower  Ordovicic),  leaving 
to  the  second  part  those  of  the  Middle  and  Upper  Champlainic  (Trenton- 
Lorraine)  and  of  the  Ontario,  or  Siluric. 

In  view  of  the  facts  that,  since  the  publication  of  Hall’s  classical  memoir 
on  the  Quebec  graptolites,  40  years  ago,  for  the  Canadian  Geological  Survey 
(partly  republished  in  the  20th  annual  report  of  the  New  York  State  Cabinet 
of  Natural  History),  no  statement  of  the  general  results  of  graptolite  researches 
has  appeared  in  print  on  this  continent,  and  that  the  recent  literature  on  this 
subject  is  widely  scattered,  and  some  of  it  difficult  of  access,  this  memoir  is 
introduced  by  a  resume  of  the  present  status  of  our  knowledge  of  graptolites. 

During  the  prosecution  of  this  study,  I  have  had  the  constant  aid  and 
encouragement  of  the  state  paleontologist,  to  whom  I  am  indebted  for  access 
to  literature  connected  with  the  subject  and  other  necessaries  of  investigation. 


458 


NEW  YORK  STATE  MUSEUM 


To  him  my  most  sincere  thanks  are  due.  I  am  also  under  obligation  to 
Mr  Charles  Schuchert,  who  kindly  placed  at  my  disposal  the  material 
collected  by  Messrs  Walcott,  Dale  and  Prindle  during  the  prosecution  of 
their  work  in  the  slate  belt,  and  deposited  now  in  the  collection  of  the 
National  Museum.  Prof.  R.  P.  Whitfield  has  kindly  allowed  me  access  to 
the  Quebec  graptolites  of  the  Hall  collection  in  the  American  Museum  of 
Natural  History ;  and  Mr  Gilbert  van  Ingen  of  Princeton  University  has 
generously  given  me  the  benefit  of  his  skill  in  photographing  the  obscure 
appendages  of  these  organisms. 

Rudolf  Ruedemann 
Assistant  State  Paleontologist 


INTRODUCTION 


1  References1 

1724  Bromell,  M.  v.  Litkographia  Suecanae.  Specimen  prim,  et  secund.  Acta  lit. 

Sueciae  Upsaliae  public,  v.  1  and  2  (1720-29) 

1735  Linne,  C.  v.  Systema  naturae,  ed.  1.  Regnum  lapideum.  Classis  3,  Fossilia. 
Ordo.  3 

1821  Wahlenberg,  G.  Petrificata  Telluris  Suecanae.  Nova  Acta  Reg.  Soc.  Scien- 

tiarum  Upsal,  8  :  92 

1822  Schlotheim,  E.  F.  v.  Petrefaktenkunde,  p.  56 
1828  Brongniart,  A.  Histoire  des  Vegetaux  Fossiles,  p.  70 

Nilsson.  See  Dr  Beck  in  Murchison.  Silurian  System,  p.  696 
1837  Hisinger,  W.  Lethaea  Suecica,  seu  Petrificata  Sueciae.  Supplementum 

1839  Murchison,  R.  J.  Silurian  System,  pt  2,  p.  695 

1840  Quenstedt,  F.  A.  Ueber  die  vorziiglicksten  Kennzeichen  der  Nautileen.  Neues 

Jalirb.  fur  Mineral,  p.  253 

1842  Geinitz,  H.  B.  Neues  Jakrbuch  fiir  Mineralogie,  p.  697 

1842  Vanuxem,  L.  Geology  of  New  York.  Report  on  Third  District 

1843  Portlock,  J.  E.  Geological  Report  on  Londonderry,  Tyrone  and  Fermanagh 
1843  Mather,  W.  W.  Geology  of  New  York.  Report  on  First  District 

1843  Emmons,  E.  Geology  of  New  York.  Report  on  Second  District 
1843  Hall,  J.  Geology  of  New  York.  Report  on  Fourth  Geological  District 

1846  Geinitz,  H.  B.  Grundriss  der  Versteinerungskunde,  p.  310 

1847  Hall,  J.  Palaeontology  of  New  York,  v.l 

1848  Sedgwick,  A.  On  the  Organic  Remains  found  in  the  Skiddaw  Slates,  etc.  Quar. 

Jour.  Geol.  Soc.  4:216 

1850  Barrande,  J.  Graptolites  de  Boheme  extraits  du  systeme  silurien  du  centre  de  la 
Boheme 

1  For  lists  of  graptolite  literature,  see  Perner,  J.  fitudes  sur  les  Graptolites  de  Boheme,  2  ieme 
partie,  p.  3;  Wiman,  C.  Ueber  die  Graptoliten,  p.  2;  Roemer  &  Freeh.  Lethaea  palaeozoica, 
1:544;  Elies  &  Wood.  Monograph  of  British  Graptolites.  The  list  here  given  does  not  contain  the 
greater  portion  of  the  literature  on  Upper  Siluric  forms. 


460 


NEW  YORK  STATE  MUSEUM 


1850  McCoy,  F.  On  some  New  Genera  and  Species  of  Silurian  Radiata  in  the  Col¬ 

lection  of  the  University  of  Cambridge.  Ann.  and  Mag.  Nat.  Hist.  G :  270 

1851  -  British  Palaeozoic  Fossils  in  the  Geological  Museum  of  the  University  of 

Cambridge,  pt  2,  p.  3 

1851  Salter,  J.  W.  In  Murchison.  Silurian  Rocks  of  Scotland.  Quar.  Jour.  Geol. 
Soc.  7 : 173 

1851  Scharenberg,  W.  Ueber  Graptolithen  mit  besonderer  Beriicksichtigung  der  bei 

Christiania  vorkommenden  Arten 

1852  Geinitz,  H.  B.  Die  Yersteinerungen  der  Grauwacken  Formation  in  Sachsen,  etc. 

Heft  1 

1852  Salter,  J.  W.  Description  of  some  Graptolites  from  the  South  of  Scotland. 

Quar.  Jour.  Geol.  Soc.  8  : 388 
1852  Hall,  J.  Palaeontology  of  New  York,  v.2 
1855  Emmons,  E.  American  Geology,  v.l 

1857  Hall,  J.  Geological  Survey  of  Canada.  Report  of  Progress 
1857  -  Canadian  Naturalist  and  Geologist,  v.3 

1859  -  Notes  upon  the  Genus  Graptolithus.  N.  Y.  State  Cab.  Nat.  Hist.  12th 

An.  Rep’t,  p.  45,  58 

1859  -  Palaeontology  of  New  York,  v.3,  supplement 

1860  -  N.  Y.  State  Cab.  Nat.  Hist.  13th  An.  Rep’t,  p.  55 

1863  Salter,  J.  W.  Note  on  Skiddaw  Slate  Fossils.  Quarterly  Journal  of  the 
Geological  Society,  19:  135 

1865  Hall,  J.  Geological  Survey  of  Canada.  Figures  and  Descriptions  of  Canadian 
Organic  Remains,  decade  2 

1865  Tornquist,  S.  L.  Om  Fagelsangstraktens  Undersiluriska  lager.  Lunds  Univ. 
Arsskrift.  Tom.  2 

1867  Nicholson,  H.  A.  On  a  New  Genus  of  Graptolites  with  Notes  on  Reproductive 
Buds.  Geol.  Mag.  4 :  256 

1867  Carruthers,  W.  Graptolites:  their  Structure  and  Systematic  position.  Intellec¬ 

tual  Observer,  11:283,  365 

1868  Hall,  J.  Introduction  to  the  Study  of  the  Graptolites.  N.  Y.  State  Cab.  Nat. 

Hist.  20th  An.  Rep’t 

1868  Carruthers,  W.  Revision  of  the  British  Graptolites,  with  Descriptions  of  the 
New  Species,  etc.  Geol.  Mag.  5  :  64 

1868  Nicholson,  H.  A.  Graptolites  of  the  Skiddaw  Series.  Quar.  Jour.  Geol.  Soc. 
24:125 


GRAPTOLITES  OF  NEW  YORK,  TART  1 


461 


1868  - On  the  Nature  and  Geological  Position  of  the  Graptolitidae.  Ann.  and 

Mag.  Nat.  Hist,  ser.4,  2:55 

1870  - —  On  the  British  Species  of  Didymograptus.  Ann.  and  Mag.  Nat.  Hist. 

ser.4,  5:337 

1870  Hopkinson,  J.  On  the  Structure  and  Affinities  of  the  Genus  Dicranograptus. 

Geol.  Mag.  7 :  353 

1871  -  On  Dicellograpsus,  a  New  Genus  of  Graptolites.  Geol.  Mag.  v.8,  no.l,  p.20 

1871  -  On  a  Specimen  of  Diplograpsus  pristis  with  Reproductive  Capsules. 

Ann.  and  Mag.  Nat.  Hist,  ser.4,  7 :  317 

1871  Richter,  R.  Aus  dem  thiiriugischen  Schiefergebirge.  Zeitschr.  geol.  Ges.  23:231 

1872  Hopkinson,  J.  On  the  Occurrence  of  a  Remarkable  Group  of  Graptolites  in  the 

Arenig  Rocks  of  St  David’s,  South  Wales.  Geol.  Mag.  9  :467 
1872  Nicholson,  H.  A.  A  Monograph  of  the  British  Graptolitidae 
1872  Allman,  G.  J.  A  Monograph  of  the  Gymnoblastic  or  Tubularian  Hydroids. 
London 

1872  -  On  the  Morphology  and  Affinities  of  Graptolites.  Ann.  and  Mag.  Nat. 

Hist.  ser.  4,  9  :  364 

1873  Hopkinson,  J.  On  some  Graptolites  from  the  Upper  Arenig  Rocks  ot  Ramsay 

Island,  St  David’s.  Geol.  Mag.  v.10,  no.ll,  p.518 
1873  Dames,  W.  Beitrag  zur  Kenntniss  der  Gattung  Dictyonema  Hall.  Zeitschr.  d. 
deutsch.  geol.  Gesellsch.  25:383 

1873  Nicholson,  H.  A.  On  some  Fossils  from  the  Quebec  Group  of  Point  Levis, 
Quebec.  Ann.  and  Mag.  Nat.  Hist,  ser.4,  11 : 133 

1873  Lapworth,  C.  Notes  on  the  British  Graptolites  and  their  Allies.  1 — On  an 

Improved  Classification  of  the  Rhabdophora,  pt  1,  pt  2.  Geol.  Mag.  10  :  500,555 

1874  Etheridge,  R.jr.  Observations  on  a  few  Graptolites  from  the  Lower  Siluric  Rocks 

of  Victoria,  Australia,  etc.  Ann.  and  Mag.  Nat.  Hist,  ser.4,  v.14 

1874  McCoy,  F.  Geological  Survey  of  Victoria.  Prodr.  Pal.  Victoria,  Dec.  1,  p.3 

1875  - Dec.  2,  p  29 

1875  Hopkinson,  J.  &  Lapworth,  C.  On  the  Graptolites  of  the  Arenig  and  Llandeilo 
Rocks  of  St  David’s.  Quar.  Jour.  Geol.  Soc.  31 :  631 

1875  Nicholson,  H.  A.  On  a  New  Genus  and  some  New  Species  of  Graptolites  from 

the.  Skiddaw  Slates.  Ann.  and  Mag.  Nat.  Hist,  ser.4,  16  :269 

1876  McCoy,  F.  On  a  New  Victorian  Graptolite.  Ann.  and  Mag.  Nat.  Hist,  ser.4, 

18:128 


462 


NEW  YORK  STATE  MUSEUM 


1876  Linnarsson,  G.  On  the  Vertical  Range  of  Graptolites  in  Sweden.  Geol.  Mag. 
Dec.  2,  v.3,  no.6,  p.241 

1S76  Nicholson,  H.  A.  Notes  on  the  Correlation  of  the  Graptolitic  Deposits  of  Sweden 
with  those  of  Britain.  Geol.  Mag.  Dec.  2,  v.3.  no.6,  p.245 

1876  Tornquist,  S.  L.  Nyblottad  profil  med  PhyllograptusskifEer  i  Dalarne.  G.  F.  F. 

no. 36,  Bd3,  no. 8,  p.241 

1877  Linnarsson,  G.  Om  graptolitskiffern  vid  Ivongslena  i  Vestergotland.  G.  F.  F. 

no. 41,  Bd3,  p.402 

1878  Giimbel,  C.  W.  Einige  Bemerkungen  iiber  Graptoliten.  B.  Mittheilungen  an 

Professor  H.  B.  Geinitz,  Miinchen,  den  21  Jan.  Neues  Jahrb.  p.292 
Richter,  R.  Brief.  Ibid,  p.639 

1878  McCoy,  F.  Prodromus  of  the  Palaeontology  of  Victoria,  Dec.  5 

1879  Spencer,  J.  W.  Graptolites  of  the  Niagara  Formation.  Can.  Naturalist.  1878-79. 

p.457 

1879  Tornquist,  S.  L.  Nagra  iakttagelser  ofver  Dalarnes  graptolitskiffrar.  G.  F.  F. 
Bd4,  no. 14 

1879  Linnarsson,  G.  Jakttagelser  ofver  de  graptolitfbrande  skiffrarne  i  Skane. 
G.  F.  F.,  no. 50,  Bd4,  p.227  and  S.  G.  U.  ser.C,  no.31 

1879  -  Om  Gotlands  graptoliter.  Of  vers,  af  Kongl.  Vet.  Akad’s  Forh.  no.5, 

and  S.  G.  U.  ser.C,  no.37 

1879-80  Lapworth,  C.  On  the  Geological  Distribution  of  the  Rhabdophora.  Ann. 
and  Mag.  ser.5,  3:245,  449;  4:333,423;  5:45,273,358;  6:16,185 

1880  Zittel,  K.  Handbuch  der  Palaeontologie,  1 :  290 

1880  Lapworth,  C.  On  New  British  Graptolites.  Ann.  and  Mag.  Nat.  Hist,  ser.5, 
5:149 

1880  Tullberg,  S.  A.  Nagra  Didymograptus-arter  i  undre  graptolitskiffer  vid  Kiviks- 

Esperod.  G.  F.  F.,  no.58,  Bd5,  no.2,  p.39 

1881  Tornquist,  S.  L.  Studier  ofver  Retiolites.  G.  F.  F.,  no. 63,  Bd5,  no.7,  p.293 

1881  -  Om  nagra  graptolitarter  fran  Dalarne.  G.  F.  F.,  no.66,  Bd5,  no.10, 

p.435 

1881  Holm,  G.  Tvenne  nya  sliigten  af  familjen  Dichograptidae  Lapw.  Ofvers.  af 

Kongl.  Vet.  Akad’s  Forh.  no.9,  p.45 

1882  Hopkinson,  J.  On  some  Points  in  the  Morphology  of  the  Rhabdophora  or  True 

Graptolites.  Ann.  and  Mag.  Nat.  Hist,  ser.5,  v.9,  p.54 
1882  Brogger,  W.  C.  Die  silurischen  Etagen  2  and  3  im  Kristianiagebiet  und  auf  Eker 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


463 


1882  Tullberg,  S.  A.  Skanes  Graptoliter,  I.  Sver.  Geol.  Uiid.  ser.C,  no.50 

1883  Tornquist,  S.  L.  Ofversigt  ofver  bergsbygnaden  inorn  Siljansomradet  i  Dalarne. 

Sver.  Geol.  Und.  ser.C,  no.57 

1884  Spencer,  J.  W.  Niagara  Fossils,  1.  Graptolitidae  of  tbe  Upper  Silurian  System. 

Mus.  Univ.  Missouri.  Bui. 

1885  Herrmann,  M.  O.  Die  Graptolitheufamilie  Dichograptidae,  Lapvv.,  mitbesonderer 

Beriicksiclitigung  von  Arten  aus  dem  norwegischen  Silur.  Nyt.  Mag.  Naturv. 
29de  Bind,  p.124 

1886  Lapworth,  C.  Preliminary  Report  on  some  Graptolites  from  the  Lower  Palaeozoic 

Rocks  on  tbe  South  Side  of  the  St  Lawrence.  Roy.  Soc.  Can.  Trans. 
4:167-84 

1886  Herrmann,  M.  O.  On  the  Graptolite  Family  Dichograptidae  Lapworth.  Geol. 

Mag.  Dec.  3,  3:13 

1887  Lecrenier,  A.  Lettre,  Ann.  de  la  Soc.  Geol.  de  Belg.  Bui.  14 : 182 

1887  Malaise,  C.  Les  schistes  siluriens  de  Huy  et  leur  signification  geologique.  Ann. 

de  la  Soc.  Geol.  de  Belg.  Bui.  15  :39 

1888  Ami,  H.  M.  Systematic  List  of  Fossils  etc.  Apx.  to  Elis’s  2d  Rep’t  Prov.  Quebec. 

Geol.  Nat.  Hist.  Sur.  Can.  ser.2.  Rep’t  1888.  v.3,  pt2,  116  Kff 

1889  -  On  a  Species  of  Goniograptus  from  the  Levis  Formation.  Levis,  Quebec. 

Can.  Rec.  Sci.  v.3,  no. 7,  p.  422-28 

1889  Marr,  J.  E.  Notes  on  the  Lower  Palaeozoic  Rocks  of  the  Fichtelgebirge,  Frank- 
enwald  and  Thiiringerwald.  Geol.  Mag.  Dec.  3,  6 : 441 

1889  Jaekel,  O.  Ueber  das  Alter  des  sogen.  Graptolithengesteins  mit  besonderer 

Riicksickt  auf  die  in  detnselben  enthaltenen  Graptolithen.  Zeitschr.  d.  deutsck. 
geol.  Gesellsch.  41  :  653 

1890  Holm,  G.  Gotlands  Graptoliter.  Bib.  till  K.  Svenska  Vet.-Akad.  Handl.  Bdl6, 

Afd.4,  no.7 

1890  Tornquist,  S.  L.  Undersokningar  ofver  Siljansomradets  Graptoliter,  I.  Lunds 
Univ.  Arsskrift,  Bd26 

1890  Nicholson,  H.  O.  Note  on  the  Occurrence  of  T  r  igo  n  ograp  tu  s  ensiformis 
Hall  sp.  and  of  a  Variety  of  Didymograptusv-fractus  Salter,  in  the 
Skiddaw  Slates.  Geol.  Mag.  new  ser.  Dec.  3,  7  :340 
1890  Malaise,  C.  Sur  les  graptolites  de  Belgique.  Acad.  r.  d.  Belg.  Bui.  d.  s.  20,  p.440 
1890  Moberg,  J.  C.  Om  en  Afdelning  inom  Glands  Dictyonema-skiffer.  Sver.  Geol. 
Und.  Afh.  och  upps.  ser.C,  no.109 


464 


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1891  Matthew,  G.  F.  On  a  New  Horizon  in  the  St  John  Group 

Read  at  meeting  of  the  Natural  History  Society  of  New  Brunswick,  Oct.  5,  1871. 
Reprinted  from  Canadian  Record  of  Science,  Oct.  1891 

1892  Tornquist,  S.  L.  Undersbkningar  ofver  Siljansomradets  Graptoliter  2.  Lunds 

Univ.  Arsskrift.  Bd  28 

1892  Barrois,  C.  Memoire  sur  la  distribution  des  Graptolites  en  France.  Ann.  de  la 
Soc.  geol.  du  Nord,  20:  75 

1892  Moberg,  J.  C.  Ora  skiffern  med  Clonograptus  ten  e  1 1  u  s  ,  dess  fauna  och 
geologiska  alder.  G.  F.  F.,  no.142,  Bdl4,  H.2,  p.87  and  Sver.  Geol.  Und. 
ser.C,  no. 125, 1 

1892  -  Om  nagra  nya  graptoliter  fran  Skanes  Undre  Graptolitskiffer.  G.  F.  F., 

no.144,  Bdl4,  H.4,  p.339  and  Sver.  Geol.  Und.  ser.C,  no. 125,  3 
1892  Giirich,  G.  Schlesische  Gesellschaft  fur  vaterliindische  Kultur.  Naturw.  Classe 
1892  Gurley,  R.  R.  The  Geologic  Age  of  the  Graptolite  Shales  of  Arkansas.  Ark. 
Geol.  Sur.  An.  Rep’t.  1890.  3  : 401 

1892  -  New  Species  of  Graptolites.  Ibid,  p.416 

1893  Tornquist,  S.  L.  Observations  on  the  Structure  of  some  Diprionidae.  Fisio- 

grafiska  Siillskapets  Handlingar.  Ny  foljd,  Bd4 
1893  Sollas,  J.  W.  On  the  Minute  Structure  of  the  Skeleton  of  Monograptus  priodon. 
Geol.  Mag.  Dec.  3,  10:551 

1893  Barrois,  C.  Sur  le  Rouvilligraptus  richardsoni  de  Cabrieres.  Ann.  de  la  Soc. 
geol.  du  Nord,  21 : 107 

1893  Wiman,  C.  Ueber  Diplograptidae  Lapworth.  Geol.  Inst.  Upsala.  Bui.  2,  v.l 

1893  -  Ueber  Monograptus  Geinitz.  Ibid. 

1894  Tornquist,  S.  L.  Nagra  anmarkningar  om  graptolitemas  terminologi.  G.  F.  F., 

no. 158,  Bdl6,  H.4,  p.375 

1894  Marr,  J.  E.  Notes  on  the  Skiddaw  Slates.  Geol.  Mag.  new  ser.  Dec.  4,  v.l,  no.3, 

p.122 

1894  Hall,  T.  S.  Note  on  the  Distribution  of  the  Graptolitidae  in  the  Rocks  of  Castle- 

maine.  Austral.  Ass’n  Adv.  Sci.  Rep’t,  p.374 
1894-97  Perner,  J.  Btudes  sur  les  Graptolites  de  Boheme.  1,  2,  3  ieme  partie 

1895  Holm,  G.  Om  Didymograptus,  Tetragraptus  och  Phyllograptus.  G.  F.  F.,  no.164,  * 

Bdl7,H.3,  p.319 

1895  Ruedemann,  R.  Synopsis  of  the  Mode  of  Growth  and  Development  of  the 
Graptolitic  Genus  Diplograptus.  Am.  Jour.  Sci.  ser.3,  v.49,  no.294,  p.453 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


465 


1895  Wiman,  C.  Ueber  die  G-raptolithen.  Diss.  Geol.  Inst,  Upsala.  Bui.  v.2,  no. 2 
1895  Matthew,  G.  F.  Two  New  Cambrian  Graptolites  with  Notes  on  other  Species  of 
Graptolitidae  of  that  Age.  N.  Y.  Acad.  Sci.  Trans.  Aug.  29 

1895  Ruedemann,  R.  Development  and  Mode  of  Growth  of  Diplograptus  McCoy. 

N.  Y.  State  Geol.  An.  Rep’t  1894,  p.219 

1896  Gurley,  R.  R.  North  American  Graptolites.  Jour.  Geol.  v.4,  no.l,  p.63;  v.4, 

no.3,  p.291 

1896  Wiman,  C.  Structure  of  the  Graptolites.  Natural  Sci.  9  : 186 

1896  -  Ueber  D  i  c  ty  o  n  e  m  a  cavernosum  n.sp,  Geol.  Inst.  Upsala.  Bui.  5, 

v.3 

1897  Tornquist,  S.  L.  On  the  Diplograptidae  and  Heteroprionidae  of  the  Scanian 

Rastrites  beds.  Kongl.  Fysiogr.  Siillsk.  i  Lund  Handl.  Ny  Foljd.  Bd  8 
1897  Tornquist,  A.  Neuere  Arbeiten  liber  die  Graptolithen.  Zool.  Centralblatt, 
4  Jahrg.  no. 23 

1897  Walther,  J.  Ueber  die  Lebensweise  fossiler  Meeresthiere.  Zeitschr.  d.  deutsch. 
geol.  Gesellscli.  49  :  210 

1897  Roemer,  F.  &  Freeh,  F.  Lethaea  palaeozoica,  1 :  544 

1897  Wiman,  C.  Ueber  den  Bau  einiger  gotlandischen  Graptoliten.  Geol.  Inst. 

Upsala.  Bui.  6,  v.3,  pt2,  p.352 

1898  Ruedemann,  R.  Synopsis  of  Recent  Progress  in  the  Study  of  Graptolites.  Am. 

Naturalist,  v.32,  no.373 

1898  Elies,  G.  L.  Graptolite  Fauna  of  the  Skiddaw  Slates.  Quar.  Jour.  Geol.  Soc. 
54 : 463 

1900  Wiman,  C.  Uber  die  Borkholmer  Schicht  im  Mittelbaltischen  Silurgebiet. 
Geol.  Inst.  Upsala.  Bui.  10,  v.5,  pt2 

1900  Elies,  G.  L.  Zonal  Classification  of  the  Wenlock  Shales  of  the  Welsh  Borderland. 
Quar.  Jour.  Geol.  Soc.  56:370 

1900  Wood,  E.  M.  R.  The  Lower  Ludlow  Formation  and  its  Graptolite  Fauua.  Quar. 
Jour.  Geol.  Soc.  56  :415 

1900  Lapworth,  H.  The  Silurian  Sequence  of  Rhayader.  Quar.  Jour.  Geol.  Soc. 

56:67 

1901  Tornquist,  S.  L.  Researches  into  the  Graptolites  of  the  Scanian  and  Ves.trogothian 

Phyllo-Tetragraptus  Beds.  Lunds  Univ.  Arsskrift,  Bd37,  Afd2,  no.5 
1901-2  Elies,  G.  L.  &  Wood,  E.  M.  R.  Monograph  of  British  Graptolites ;  ed.  by 
C.  Lapworth,  pt  1  and  2.  Pal.  Soc.  vol.  for  1901  and  1902 


466 


NEW  YORK  STATE  MUSEUM 


1 901  Ruedemann,  R.  Hudson  River  Beds  near  Albany  and  their  Taxonomic  Equiva¬ 

lents.  1ST.  Y.  State  Mus.  Bui.  42 

1902  -  Graptolite  Facies  of  the  Beekmantown  Formation  in  Rensselaer  County, 

N.  Y.  N.  Y.  State  Paleontol.  An.  Rep’t.  N.  Y.  State  Mus.  Bui.  52,  p.546 

1902  -  Growth  and  Development  of  Goniograptus  thureaui  McCoy.  Ibid,  p.576 

1903  -  Upper  Cambric  Horizon  of  Dictyonema  flabelliforme  in  New  York. 

N.  Y.  State  Paleontol.  An.  Rep’t.  N.  Y.  State  Mus.  Bui.  69,  p.934 

2  History  of  the  study  of  the  graptolites1 

In  examining  a  piece  of  black  Siluric  shale,  one  often  notices  on  its 
surface  peculiar  figures  which,  by  their  form  and  substance  suggest  pencil 
markings.  They  are  nearly  always  toothed  like  a  saw  on  one  or  both  sides. 
Linne  described,  together  with  other  objects  of  different  character,  some 
of  these  markings  under  the  very  appropriate  generic  term  “  Graptolithus.” 
This  word  has  provided  a  name  for  the  whole  class  of  fossil  organisms. 

The  frequently  leaflike  shape,  serrate  margin  and  carbonaceous  sub¬ 
stance  of  the  fragments  which  alone  were  known  to  the  early  observers,  led 
them  to  consider  these  bodies  as  of  vegetable  origin,  a  view  held  specially  by 
Bromett  and  Brongniart ,  and  also  current  among  some  of  the  members  of 
the  Geological  Survey  of  New  York,  who  in  their  works  refer  to  the 
graptolites  as  “  fucoids.” 


1  The  early  history  of  the  study  of  graptolites  has  been  exhaustively  treated  by  James 
Hall  in  his  memoir,  Graptolites  of  the  Quebec  Group  [§  8,  Historical  notice  of  the 
genus  Graptolithus,  p.  59]  and  in  his  “Introduction  to  the  study  of  the  Graptolitidae ” 
[N.  Y.  State  Cab.  Nat.  Hist.  20th  An.  Rep’t].  These  publications  well  depict  the 
progress  in  the  conception  of  the  graptolites  from  Linne  onward  and  the  state  of  our 
knowledge  of  this  group  of  fossils  at  the  beginning  of  the  last  third  of  the  last  century. 
Referring  the  reader  to  this  earlier  publication  on  the  subject  in  a  report  from  this 
office,  we  will  mention  only  the  most  important  events  of  the  history  up  to  Hall’s 
fundamental  work  and  restrict  ourselves  to  a  fuller  treatment  of  the  later  history.  The 
more  important  later  investigations  are  also  incidentally  mentioned  in  Zittel’s  History  of 
Geology  and  Paleontology  [1901];  and  the  latest  discoveries  the  reader  will  find  more 
fully  discussed  in  publications  by  C.  Wiman  [1895, 1896],  A.  Tornquist  [1897],  and  the 
present  writer  [1898J. 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


467 


The  first  to  consider  the  graptolites  as  of  animal  nature  was  Wafoh , 
who  described  two  species  as  toothed  Orthoceratites.  This  conception 
of  the  graptolites  was  subsequently  maintained  by  Wahlenberg,  Schloth- 
heim  and  for  a  time,  also  by  Geinitz  and  Quenstedt. 

Nilsson  appears  to  have  been  the  first  observer  who  pointed  out  the  sim¬ 
ilarity  of  the  structure  of  the  graptolites  to  that  of  recent  hydrozoans.  Beck , 
Murchison  and  JPortlock  held  the  same  view,  Portlock  comparing  them  with 
Sertularia  and  Plumularia;  while  Barrande,  who  first  (in  1850)  described 
exhaustively  a  whole  graptolite  fauna,  that  of  Bohemia,  disproved  fully  the 
relation  of  the  graptolites  to  the  cephalopods. 

As  early  as  1847,  Hall  described  and  finely  illustrated  ( Palaeontology 
of  New  York,  v.l)  one  species  from  the  Trenton  and  13  species  from 
the  Utica  and  “Hudson  river”  shales  of  New  York,  stating  [p.  265]  his 
agreement  with  the  view  of  Dr  Beck,  viz  that  the  graptolites  are  to 
be  compared  with  Virgularia.  In  1849  he  announced  before  the  American 
Association  for  the  Advancement  of  Science  [Proc.  1849,  p.  351]  the  occur¬ 
rence  of  20  species  of  graptolites  in  the  Lower  Siluric  rocks,  and  of  three 
species  in  the  Clinton  formation.  The  latter,  together  with  the  genus 
Dictyonema,  have  been  described  and  figured  in  the  second  volume  of  the 
Palaeontology  of  New  York. 

In  1855  Emmons  described  as  new  14  species,  from  various  localities, 
largely  from  the  shales  of  Columbia  county,  N.  Y.  and  of  Virginia,  and  three 
new  genera,  Nemagrapsus,  Glossograpsus  and  Staurograpsus,  attaching  the 
last  designation  to  a  Cambric  form,  more  fully  noticed  in  the  present 
publication. 

When  a  finely  preserved,  rich  and  new  fauna  of  graptolites  was  dis¬ 
covered  by  the  Canadian  geologists  in  the  Lower  Siluric  rocks  of  Point  Levis 
near  Quebec,  it  was  intrusted  to  Hall  for  description.  In  a  preliminary  pub¬ 
lication  [1857]  21  new  species  were  announced  from  these  rocks  of  uncertain 
stratigraphic  position.  The  same  fauna  was  more  fully  treated,  beautifully 
illustrated  by  engravings  on  copper,  and  numerous  new  species  from  the  same 


468 


NEW  YORK  STATE  MUSEUM 


rocks  added  in  Hall’s  most  important  work  on  this  subject,  Graptolites  of 
the  (Quebec  Group  [1865].  In  this  memoir,  which  is  classical  for  the  study  of 
American  graptolites,  all  the  evidence  collected  up  to  that  time  by  Barrande, 
Geinitz,  Hall  and  other  observers,  is  critically  discussed,  and  the  compound 
form  of  numerous  Dichograptidae  and  the  presence  of  a  .central  disk,  in  con¬ 
trast  to  the  fragmentary  material  then  known  in  Europe,  fully  set  forth. 
Further,  three  new  graptolites  from  the  Utica  shale  of  Lake  St  John,  Canada, 
among  these  a  compound  Retiograptus,  are  described  in  a  supplement. 

As  Hall’s  conception  of  the  graptolites,  laid  down  in  this  work,  was 
adopted  generally  and  finds,  on  the  whole,  expression  in  the  textbooks  still  in 
use,  though  recent  investigations  have  greatly  modified  it,  we  here  cite  his  most 
important  views.  He  states  that  it  is  shown,  both  from  analogies  and  from 
the  mode  of  development  or  reproduction  exhibited  in  some  of  the  species,1 
that  they  are  true  “  Polypi,”  and  comparable  to  Sertularia  and  Plumularia.  He 
clearly  recognized  the  common  canal  as  connecting  the  denticles  (“  calycles  ” 
or  “  cellules  ”)  of  the  stipes.  The  calycles  were  properly  conceived  as  the 
habitations  of  zooids  (polypi).  But  it  was  held  with  Barrande  that  all  “  grap¬ 
tolites  proper  ”  (this  excludes  Dictyonema  etc.)  had  a  solid  axis,  a  view  which, 
as  we  shall  explain  later  on  [p.  487],  has  been  disproved ;  and  that  the  saw¬ 
like,  theciferous  stipes  were  united  by  connecting  processes  which  “  were 
always  destitute  of  cellules,”  and  were  therefore  “  funicles.”  Recent  investi¬ 
gations  have  demonstrated  the  composition  of  these  connecting  processes  of 

1This  refers  to  the  discovery  in  the  Normanskill  shale  in  the  neighborhood  of 
Albany,  of  a  Diplograptus  with  peculiar,  apparently  saclike  appendages  of  the  stipes, 
which  he  compared  to  the  gonangia  of  the  Ilydrozoa.  A  note  on  this  discovery  had  been 
published,  together  with  the  description  of  two  new  species  from  the  Normanskill  shale, 
in  the  12th  annual  report  of  the  New  York  State  Cabinet  [1859]  and  reprinted, 
augmented  by  the  descriptions  of  five  more  species  and  several  new  genera  from  the  same 
shales,  in  the  Paleontology  of  New  York ,  volume  3,  supplement.  As  the  writer  has  demon¬ 
strated  elsewhere  [1895],  the  siculae  of  Diplograptus  are  produced  in  sacs,  encircling  the 
central  disk  of  the  compound  fronds,  and  the  appendages  described  by  Hall  had  probably 
some  other  function. 


GRAPTOLITES  OB’  NEW  YORK.  PART  1 


469 


thecae  or  cellules.  As  to  the  mode  of  existence  of  the  graptolites,  Hall  con¬ 
cluded  that  the  graptolites  proper  “  in  their  mature  condition  were  free  floating 
bodies  in  the  Silurian  seas.”  In  regard  to  the  genera  Hendrograptus,  Callo- 
graptus  and  Dictyonema,  he  held  that  the  frequent  bulblike  enlargements  at 
the  base  indicate  attachment  to  bodies  or  an  embedding  in  the  mud.  Even  at 
the  present  opinions  in  regard  to  the  mode  of  life  of  the  graptolites  are  greatly 
at  variance,  and  the  problem  has  apparently  not  yet  been  solved  to  general 
satisfaction. 

The  introduction  to  the  Graptolites  of  the  Quebec  Group ,  somewhat 
enlarged  and  with  the  addition  of  supplementary  notes  on  certain  genera,  has 
been  reprinted  under  the  title,  “Introduction  to  the  Study  of  the  Grap- 
tolitidae,”  in  the  20th  annual  report  of  the  New  York  State  Cabinet  [1868]. 
This  publication  closed  Hall’s  work  on  the  graptolites. 

In  tracing  the  subsequent  development  of  our  knowledge  of  the  grap¬ 
tolites,  it  will  greatly  facilitate  the  grasp  of  the  subject  if  we  keep  apart  two 
different  trends  of  investigation.  As  the  graptolites  not  only  became  interest¬ 
ing  and  important  as  a  class  per  se,  which  invited  investigation  by  its  early 
extinction,  the  great  variety  of  forms  displayed  and  the'  ignorance  of  their 
internal  structure  among  paleontologists,  but  were  also  recognized  as  the  most 
reliable  and  widely  distributed  index  fossils  for  the  determination  of  horizons 
of  the  Upper  Cambric  and  Siluric,  their  study  has  been  pursued  from  the 
standpoint  of  the  biologist  as  well  as  from  that  of  the  stratigrapher. 

We  will  first  take  up  the  investigations  of  the  stratigraphic  relations  of 
the  graptolites,  as  these  attracted  the  attention  of  numerous  geologists  long 
before  their  biologic  aspect.  This  work  had  naturally  to  begin  with  the 
descriptions  of  the  faunas  found  in  the  rocks  of  various  regions.  It  can  be 
claimed  that  Barrande  and  Hall  laid  the  foundations  of  this  branch  of  the 
science  by  describing  the  graptolite  faunas  of  Bohemia  and  eastern  North 
America.  At  the  same  time,  however,  the  exploitation  of  the  graptolite 
schists  of  Scotland,  northern  England  and  Wales  had  been  undertaken  by 
the  well  known  pioneers  of  British  geology,  among  whom  we  enumerate 


470 


NEW  YORK  STATE  MUSEUM 


Sedgwick,  who  [1848J  described  graptolites  from  the  Skiddaw  slates  in  north 
England;  Salter ,  who  [1848]  recognized  some  of  Hall's  Norman  skill  shale 
forms  in  the  slates  of  Loch  Ryan,  described  other  species  from  the  rocks  of 
Scotland  in  1851  and  1852,  in  1861  proposed  the  new  genus  Dichograptus, 
and  in  1863  Tetragraptus ;  McCoy ,  who  erected  the  genus  Diplograpsus 
[1850]  and  described  numerous  species  from  British  paleozoic  rocks,  recog¬ 
nizing  several  American  species  among  them,  in  the  British  Palaeozoic 
Fossils  [1851];  and  darkness  [1850],  who  described  the  graptolites  of  the 
black  shales  of  Dumfriesshire,  a  work  continued  by  Carruthers  in  1858. 

On  the  continent  Suess  [1851]  added  considerably  to  the  list  of  forms 
made  known  by  Barrande  from  Bohemia  ;  and  Geinitz  [1852]  described  the 
graptolites  of  Saxony. 

In  America  Hall’s  work  found  early  response.  Billings  [1861]  compared 
the  zones  of  Europe  and  America  and  endeavored  to  show  that  the  graptolite 
shales  of  Normanskill  near  Albany  were  not  in  the  upper  part  of  the  Lower 
Siluric,  or  Hudson  river  group,  as  Hall  maintained,  a  contention  which 
is  now  decided  in  Billings’s  favor  [[>.490];  and  Logan  [1863]  recognized 
the  occurrence  of  graptolites  of  the  Normanskill  and  LBica  shale  of  New  York 
in  Canadian  rocks. 

The  remarkable  zonal  distribution  of  the  British  graptolites  was  however 
not  fully  recognized  nor  understood,  till  Nicholson ,  dopkinson  and,  specially, 
Lapworth  began  their  systematic  exploitation  of  the  British  graptolite  shales. 
By  their  endeavors  it  became  known  that  six  principal  divisions  can  be  dis¬ 
cerned  in  the  graptolite  shales  of  the  Upper  Cambric  and  Siluric,  that  these 
again  can  be  subdivided  into  smaller  subzones,  and  that  these  zones  show  an 
astonishing  uniformity  of  succession  throughout  the  British  Isles. 

When  finally  the  same  work  was  undertaken  in  Scandinavia  by  Linnarsson, 
it  was  found  in  Scania,  where  the  graptolite  shales  are  greatly  developed  and 
little  disturbed,  that  the  same  principal  divisions  as  in  Great  Britain  could  be 
recognized ;  and  Tullberg  and  Tbrnquist  were  able  to  subdivide  the  Swedish 
Siluric  by  means  of  the  graptolites  so  minutely  that  in  all  stratigraphy  we  find  a 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


471 


parallel  only  in  tlie  ammonite  zones  of  the  Jurassic,  Brogger  recognized  [1882] 
a  part  of  the  zones  in  Norway.  The  presence  of  like  associations  and  a  similar 
succession  have,  further,  been  recognized  by  Barrois  [1892]  in  Languedoc 
in  southern  France  and  by  Kerforne  in  the  Upper  Siluric  of  Brittany  [1901], 
The  graptolite  fauna  of  Bohemia  has,  in  continuation  of  Barrande’s  work, 
been  exhaustively  described  by  Perner. 

Hall  records  [1868,  p.233]  that  in  1861  McCoy  sent  him  a  proof  of  a 
plate  of  graptolites  from  the  Palaeontology  of  Victoria  (Australia)  with 
illustrations  of  species  identical  with  Normanskill  forms.  Before,  however, 
that  work  appeared,  R.  Etheridge  jr  [1874]  had  made  us  acquainted  with 
some  of  the  Lower  Siluric  graptolites  of  Victoria.  In  decades  1,  2  and  5 
of  the  prodromes  of  the  Palaeontology  of  Victoria  [1877-78]  McCoy  gave 
detailed  descriptions  and  illustrations  of  these  interesting  graptolites  from  the 
auriferous  shales  of  Victoria.  Nearly  all  forms  are  identified  with  species 
known  from  the  American  and  British  graptolite  rocks;  and  one  new  genus, 
Goniograptus,  first  discovered  in  Australia,  has  since  been  announced  in  the 
same  species  from  the  Quebec  rocks  by  Ami  [1889]  and  from  the  Deep  kill 
by  the  present  writer  [1901]. 

In  the  last  decade  our  knowledge  of  the  faunas  of  the  British  graptolite 
beds  has  been  greatly  augmented  by  the  work  carried  on,  under  the  safe 
guidance  of  Lapworth,  by  Elies  [1898].  These  authors  have  now  united  and, 
with  the  collaboration  of  Miss  Wood,  have  undertaken  the  arduous  task  of 
monographing  the  British  graptolites  and  of  reproducing  them  by  the  most 
exact  illustration  now  obtainable.  Two  instalments  of  this  monumental  work 
have  already  appeared. 

At  the  same  time  the  stratigraphy  of  the  English  graptolite  rocks  has 
been  much  furthered  by  the  investigations  of  Marr  [1889,  1894],  who  has 
also  extended  his  labors  to  the  graptolite  shales  of  Thuringia  and  the 
Fichtelgebirge  in  Germany,  the  former  field  of  Richter's  discoveries,  while 
for  the  Welsh  Upper  Siluric  a  zonal  mapping  based  upon  graptolite  zones 
has  been  carried  out  by  Elies  [1900],  Wood  [1900]  and  H.  Lapworth  [1900]. 


472 


NEW  YORK  STATE  MUSEUM 


In  America  the  work  on  the  graptolites  has  rested  for  a  long  time,  partly 
on  account  of  the  unpromising  character  of  the  graptolitiferous  rocks  and  partly 
because  the  many  new  fields  of  investigation  offered  by  a  large  continent, 
completely  held  the  attention  of  the  small  band  of  paleontologists.  Lapworih 
[1886],  however,  demonstrated  the  general  parallelism  of  the  succession 
of  the  faunas  of  Canada  and  Great  Britain ;  Matthew  [1891,  1895]  brought  out 
some  important  facts  incidental  to  his  investigations  in  the  St  John  basin ;  and 
Ami  [1888]  has  published  lists  of  graptolites  from  numerous  outcrops  of  the 
Lower  Siluric  in  Canada.  Spencer  [1884]  described  a  number  of  graptolites 
from  the  Upper  Siluric  of  Canada  and  the  West.  A  systematic  exploitation 
of  the  graptolites  of  North  America  was  commenced  by  Gurley  [1896],  but 
unfortunately  the  work  has  not  been  continued.  Muedemann  has  published 
observations  on  graptolites  of  the  Utica  shale  [1895]  and  in  later  years 
undertaken  the  investigation  of  the  “Hudson  river  shales”  of  New  York, 
demonstrating  their  composition  of  a  series  of  graptolite  zones,  ranging  from 
the  Upper  Cambric  to  the  Upper  Champlainic  [1901,  1902,  1903]. 

The  elucidation  of  the  morphology  of  the  graptolites,  of  their  internal 
characters,  of  the  structure  ©f  the  proximal  portions  and  of  the  mode  of 
development  has  met  an  almost  prohibitive  obstacle  in  the  flattened  condition 
of  the  shale  material ;  and  only  the  untiring  patience  of  some  observers  and  a 
few  fortunate  discoveries  of  superior  material  have  from  time  to  time  brought 
forth  essential  facts. 

As,  in  the  discussion  of  the  morphologic  characters  of  the  graptolites,  we 
shall  have  occasion  to  recur  in  greater  detail  to  the  views  of  preceding 
observers,  it  suffices  here  to  mention  only  the  most  important  advances  made 
in  this  branch  of  graptolitology. 

The  first  resolutely  to  attack  the  problem  of  the  internal  structure  of  the 
graptolites  was  Bai'rande.  He  first  asserted  the  invariable  presence  of  a 
solid  axis  or  “  virgula  ”  in  graptolites,  introduced  the  term  “  common  canal  ” 
for  the  tube  connecting  the  cells  and  claimed  that  forms  with  a  double  row 
of  cells  have  also  a  double  common  canal.  Barrande  also  held  that  the 


GKAPTOLITES  OF  NEW  YORK,  PART  1 


473 


extremity  of  the  stipes  with  the  smaller  cells,  was  the  younger  one,  and 
recognized  two  subdivisions,  namely  Monoprion,  with  a  single  row  of  cells, 
and  Diprion,  with  a  double  row.  As  we  shall  see  later  on,  nearly  all 
of  these  opinions  of  the  pioneer  have  been  greatly  modified.  Indeed,  only 
a  year  after  the  publication  of  Barrande’s  work,  Scharenberg  [1851]  in 
Norway,  corrected  some  of  Barrande’s  conclusions,  without  however  finding 
direct  followers.  He  claimed  that  the  division  into  Monoprion  and  Diprion 
excludes  the  branching  forms,  that  in  Diprion  there  are  not  two  independent 
series  of  cells,  but  the  latter  alternate  without  exception,  and  he  also  asserted 
that  the  narrower  extremity  is  not  necessarily  the  younger. 

Hall  adopted  Barrande’s  views  as  to  the  presence  of  a  solid  axis  in  all  forms 
and  as  to  that  of  one  or  two  common  canals,  in  Monoprion  and  Diprion  respect¬ 
ively.  He  retained  however  all  forms  in  the  genus  Graptolithus,  on  account  of 
the  discovery  of  forms,  as  G.  ramos  u  s,  which  show  “ the  occurrence  of  both 
a  single  and  a  double  series  of  cellules  upon  the  same  stipe  ”  \loc.  cit.  p.  40]. 
He  also  considered  the  use  of  the  terms  Tetragraptus  and  Dichograptus  imprac- 
tible,  as  for  the  most  part  only  fragments  of  stipes  are  found,  which  would  not 
allow  these  distinctions.  At  the  same  time  his  material  was  the  first  to  exhibit 
the  multiplicity  and  complexity  of  forms  of  branching  graptolites,  which  soon 
led  to  such  an  extended  subdivision  of  these  branching  forms  that  it  is  now 
claimed  [s<?e  Freeh]  to  have  gone  beyond  the  proper  limits. 

Hall  also  made  important  additions  to  our  knowledge  of  the  central  or 
basal  portions  of  the  colonies.  These  were  the  recognition  of  an  initial 
process  in  many  forms,  which  he  termed  the  “  radicle”  or  “initial  point”  and 
considered  the  beginning  of  the  solid  axis.  It  is  now,  under  the  term 
“  sicula  ”  introduced  by  Lapworth ,  known  as  the  mother  theca  of  the  colonies. 
Scharenberg  and  Richter  had  also  pointed  out  the  presence  of  this  organ,  the 
latter  calling  it  the  “Fuss.” 

Hall  further  concluded  that  there  is  in  the  branching  forms  a  central  con 
necting  process,  which  he  thought  to  be  always  destitute  of  celli'les  and  for 
which  he  introduced  the  term  “  funicle.”  The  opinion  concerning  the  presence 


474 


NEW  YORK  STATE  MUSEUM 


of  such  a  funicle  has  also  changed  in  the  last  years.  And  finally  he  showed  in 
several  forms  the  presence  of  a  disklike  expansion  of  the  proximal  portion, 
for  which  he  introduced  the  term  “central  disk.” 

In  the  succeeding  years  discussions  of  several  genera  appeared,  viz  of 
Didymograptus  and  Climacograptus  by  Nicholson  [1867,  1870],  and  of 
Dicranograptus,  Dicellograptus  and  Diplograptus  by  Hopkinson  [1870,  1871]. 

The  year  1872  brought  the  valuable  publications  of  Allman ,  namely  his 
Monograph  of  the  Gymnoblastic  Hy droids,  which  contains  a  chapter  on  the 
graptolites,  and  his  treatise  On  the  Morphology  and  Affinities  of  the  Graptolites. 
We  shall  have  occasion  to  notice  his  views  in  greater  detail  ,  in  succeeding 
chapters,  and,  therefore,  mention  here  but  the  most  important  inferences. 
Allman  holds  that  the  presence  of  the  virgula,  or  “  solid  axis,”  the  fact  which 
most  obviously  opposes  itself  to  an  acceptance  of  the  hydroid  affinities  of  the 
graptolites,  though  an  extremely  exceptional  struct  ure,  can  hardly  be  regarded 
as  offering  an  insurmountable  obstacle  to  the  admission  of  the  graptolites  into 
immediate  relation  with  the  Hydroidea,  in  consideration  of  a  solitary  genus, 
Rhabdopleura,  with  a  similar  rod  among  the  bryozoans.  The  calycles  of  the 
graptolite,  he  compares,  on  account  of  their  uninterrupted  internal  passage 
into  the  common  canal,  with  the  nematophores  of  the  Plumularidae,  and  the 
supposed  capsulelike  bodies,  described  by  Nicholson  and  Hopkinson  as 
gonangia  or  gonopliores,  he  believes  to  have  had  but  accidental  connection 
with  the  graptolites.  He  is  inclined  to  consider  the  graptolites  “a  very 
aberrant  hydrozoal  group  having  manifest  affinities  with  the  Hydrozoa.” 

While  the  exploitation  of  new  graptolite  fields  in  southern  Scotland 
[ Hopkinson  1872,  Lapworth  1872],  in  Shropshire  \Hopkinson  1873],  in  the 
Hartz  [ Lessen  1874]  was  taken  up  with  energy,  Lapworth  began  the 
systematic  work  on  the  distribution  and  classification  of  the  British  graptolites, 
which  has  furnished  the  basis  for  our  present  correlations  of  the  graptolite 
horizons  and  for  the  systematic  arrangement  of  the  multitude  of  forms.  In 
his  paper,  “  On  an  Improved  Classification  of  the  Rhabdophora,”  he  pointed 
out  the  development  of  the  colonies  from  a  “  germ,”  called  by  him  the  “  sicula,” 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


475 


for  which  hitherto  indefinite  terms  as  “  radicle,”  “  radicular  bar  ”  and  “  axillary 
spine  ”  had  been  used.  He  also  recognized  the  formation  of  a  solid  axis  in  its 
wall,  a  fact  verified  later  on  by  Wiman ,  emphasized  its  importance  for 
specific  distinction  and  defined  the  “  angle  of  divergence,”  and  arranged  the 
genera  into  families,  which  were  brought  under  the  subdivisions  erected 
before  by  Hophinson.  This  system  will  be  further  noticed  in  a  later  chapter 
[p.544]. 

Herrmann  [1885]  monographed  the  family  Dichograptidae  and  Jaekel 
[1889]  published  observations  on  graptolites  obtained  from  diluvial  boulders, 
demonstrating  the  presence  of  an  important  difference  in  the  thecal  structure 
of  the  species  of  Monograptus. 

While  the  faunas  of  various  regions  had  been  thoroughly  described 
and  a  great  number  and  variety  of  forms  made  known ;  the  succession 
of  the  faunas  and  faunules  had  been  established  and  an  elaborate  system  of 
zones  obtained  in  several  countries  and  these  zones  had  been  parallelized, 
thus  demonstrating  a  wonderful  rapidity  in  the  development  of  the  graptolite 
genera  and  their  distribution  over  vast  areas,  still  the  problems  of  the  internal 
structure  remained  as  unsolved  as  they  had  been  left  by  Barrande  and  Hall. 
This  can  not  be  wondered  at,  as  the  flattened  carbonized  specimens  which 
constitute  nearly  all  collections  are  unfit  for  an  elucidation  of  the  internal 
characters. 

It  is  true  that  a  few  keen  observers  drew  some  correct  conclusions  from 
such  material;  but,  as  these  were  not  readily  verified,  they  did  not  find 
general  acceptance.  Thus  it  was  claimed  by  Scharenberg  that  the  Diprion- 
idae  are  in  fact  Monoprionidae,  produced  by  an  alternate  gemmation  of 
thecae;  and  Lapworth  expressed  his  belief,  when  describing  two  species  of 
Dimorphograptus  [1876],  that  there  are  no  diprionidian  forms,  and  the 
sicula  in  all  graptolites  produces  but  one  bud.  These  views  of  Scharenberg 
and  Lapworth,  gleaned  from  shale  material,  have  been  found  to  be  correct  by 
recent  investigations  on  specimens  etched  out  of  limestone.  Positive  evidence 
was  however  not  obtained  till  the  preparation  of  sections  of  graptolites  was 
begun. 


476 


NEW  YORK  STATE  MUSEUM 


Tornquist  [1881,  1892]  first  undertook  the  study  of  sections  through 
pyritized  specimens,  mostly  diprionid  forms,  and  observed  the  connection  of 
virgula  and  sicula,  the  position  of  the  sicula  on  one  side  of  the  rhabdosome, 
the  presence  of  a  “connecting  canal,”  which  connects  the  sicula  and  the 
thecae,  and  the  position  of  the  virgula  or  solid  axis  within  a  median  septum, 
but  his  material  did  not  furnish  him  any  positive  evidence  in  regard  to  the 
single  or  double  character  of  the  common  canal  of  the  diprionid  forms. 

A  better  insight  into  the  structure  of  the  graptolites  was  obtained  by  the 
methods  of  dissolving  graptolitiferous  limestone,  first  applied  by  Gumbel 
[1878],  then  used  successfully  by  Holm  and  finally  brought  to  considerable 
perfection  by  Wiman.1 

Holm  elucidated,  by  means  of  such  material,  the  structure  of  Retiolites 
and  Stomatograptus  [1890],  among  the  diprionid  forms,  and  of  Didymograptus, 
Tetragraptus  and  Phyllograptus  [1895]  among  the  Dichograptidae.  He 
demonstrated  the  composition  of  the  “  funicle  ”  of  thecae  in  the  first  two  named 
Dichograptidae,  the  perfect  conformity  in  the  development  of  the  proximal 
parts  in  all  three  genera  and  the  fact  that  the  frond  of  Phyllograptus  is  com¬ 
posed  of  four  stipes,  coalesced  at  their  dorsal  sides.  [For  further  details 
of  his  results  see  the  generic  and  specific  descriptions  of  Phyllograptus,  and 
cli.  10],  The  same  distinguished  author  also  first  observed  the  presence  of 
smaller  tubes  attached  laterally  to  the  thecae  in  a  species  of  Dictyonema,  thus 
giving  the  first  intimation  of  the  complex  structure  of  the  dictyonemas.  • 

Wiman  [1898,  1895]  demonstrated  by  his  refined  methods  the  bilaterally 
symmetric  form  of  the  sicula  and  its  composition  of  two  parts,  the  initial  part 
of  which  is  continued  into  a  hollow  rod,  the  nema;  he  also  showed  the  initial 
distal  growth  of  the  first  theca  and  its  later  reversion,  and  the  origin  of  the 
double  row  of  thecae  of  Diplograptus  and  Climacograptus  from  one  theca, 
thus  verifying  Scharenberg’s  and  Lapworth’s  assertion,  that  the  so  called 
diprionid  forms  are  also  monoprionid.  His  important  results  on  this  subject 
will  be  noticed  more  in  detail  hereafter.  By  the  application  of  the  microtome 


1  See  description  of  these  methods  in  ch.  3,  p.  480. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


477 


to  the  Dendroidea,  which  were  hitherto,  as  regards  their  internal  structure, 
practically  untouched,  he  demonstrated  the  complex  character  of  the  rhab- 
dosomes  of  Dictyonema,  Dendrograptus  and  Inocaulis,  proving  that  they  are 
composed  of  three  kinds  of  theca. 

The  histology  of  the  periderm  first  received  attention  from  Richter 
[1871],  and  later  from  Giimhel  [1878].  No  very  elaborate  investigations  of 
the  test  wrere  made,  however,  till  Perrier  [1894]  undertook  the  study  of  the 
Bohemian  graptolites.  His  results  have  been  modified  quite  essentially  by 
Wimari’s  [1895]  and  GuricKs  [1896]  work.  [For  further  details  in  regard 
to  the  histology  of  the  periderm  see  ch.9,  p.539] 

The  mode  of  reproduction  and  development  of  the  graptolites  is  a  field  still 
very  little  exploited.  For  investigations  of  this  nature,  a  large  collection  of 
growth  stages  of  one  species  in  the  best  state  of  preservation  is  prerequisite, 
a  condition  rarely  fulfilled.  Hall  has  figured  [Can.  Grapt.  pi.  B]  some 
“germs”  without  referring  them,  however,  to  a  special  type.  In  his  “Notes 
upon  the  Genus  Graptolithus ”  he  figured  stipes  of  Diplograptus 
whitfieldi,  bearing  saclike  appendages,  which  he  regarded  as  repro¬ 
ductive  organs.  Nicholson  [1867]  observed  numerous  variously  shaped 
corneous  bodies  in  the  graptolitic  shales,  which  he  thought  to  be  remains 
of  capsules,  termed  “  Dawsonia  ”  and  held  to  have  been  “  ovarian  vesicles  ” 
or  “gonophores”  of  graptolites.  As  we  shall  see  presently  [p.738  and 
under  Dawsonia,  p.  521],  most  probably  neither  of  these  bodies  has 
anything  to  do  with  the  multiplication  and  propagation  of  the  graptolites.  In 
fact,  Nicholson'1  s  assertions  were  very  soon  objected  to  by  Carruthers  [1868], 
who  insisted  that  these  bodies  had  no  resemblance  to  the  “  gonophores  ” 
of  the  Hydrozoa,  with  which  Nicholson  had  compared  them.  The  same 
author  proposed  also  to  transfer  the  terminology  introduced  by  Allman 
and  Huxley  for  the  Hydrozoa  to  the  graptolites  [for  further  details  see  p.  482] 
and  furnished  a  detailed  analysis  of  the  relations  of  the  graptolites  to  recent 
similar  organisms ;  whereby,  by  a  process  of  exclusion,  he  concluded  that  they 
are  most  nearly  comparable  to  the  Sertularians,  but  differ  principally  in  the 


478 


NEW  YORK  STATE  MUSEUM 


presence  of  the  solid  axis  which  at  that  time  was  still  supposed  to  be  present 
in  all  graptolites  proper. 

The  investigation  of  the  proximal  parts  of  the  rhabdosomes  of  Tetra- 
graptus  and  Didymograptus  by  Holm ,  and  that  of  the  stipes  of  Diplograptus 
and  Monograptus  by  Wiman,  allow  a  conclusion  as  to  the  mode  of  develop¬ 
ment  of  these  portions  of  the  colonies.  The  latter  investigator  succeeded 
also  in  elucidating  the  mode  of  reproduction  of  thecae  in  Dictyonema, 
Dendrograptus  and  Inocaulis. 

Huedemann  [1895]  obtained  a  complete  growth  series  of  Diplo¬ 
graptus  f  o  1  i  a  c  e  u  s  and  was,  with  the  aid  of  this  material,  able  to  trace 
the  development  of  the  whole  colony  of  that  species  from  the  sicula  onward 
[p.528].  Later,  a  like  series  has  been  secured  for  a  multiramous  dichograptid, 
viz  Goniograptus  thureaui  [p.622  and  pi. 6];  and  in  this  memoir 
the  development  of  Dictyonema  flabelliforme  is  described  [p.602 
and  pi.  1]. 

The  study  of  the  phylogeny  of  the  graptolites,  aside  from  the  attempts 
at  mere  classification  by  various  authors,  was  not  taken  up  till  the  last 
decade.  Wiman  derived  different  groups  of  Monograptus,  each  by  way  of 
its  corresponding  Dimorphograptus,  from  Diplograptus  and  Climacograptus, 
thus  indicating  the  polyphyletic  origin  of  that  genus ;  and  Nicholson  and 
Marr  [1895]  have  outlined  the  path  of  development  of  the  Dichograptidae, 
taking  the  shape  and  arrangement  of  the  thecae  as  characters  of  prime 
phylogenetic  importance.  Their  results  point  also  to  a  polyphyletic  origin 
of  the  large  genera  of  this  family  and  specially  of  Tetragraptus  and  Didymo¬ 
graptus.  Their  work  has  been  largely  verified  and  ably  continued  by  Elies 
[1898]. 

The  mode  of  existence  of  the  graptolites,  finally,  has  as  a  rule  been 
touched  only  incidentally,  but  the  problem  has  lately  been  discussed  by 
Lapworth  [see  Walther  1897]. 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


479 


3  Methods  of  investigation  and  illustration 

There  is  hardly  any  other  group  of  fossils  which  is  so  uniformly  bound 
to  a  definite  kind  of  rock  as  the  graptolites  are  to  argillaceous  shale  and 
slate.  Graptolites  and  graptolite  shales  are  terms  which  are  closely 
associated  in  the  minds  of  geologists.  As  the  shale  yields  more  readily 
to  orogenic  forces  than  any  other  rock  and  therefore,  besides  being  thinly 
bedded,  is  nearly  always  pressed  into  small  folds  and  thoroughly  cleaved,  a 
shale  terrane  may  be  filled  with  graptolites  and  yet  furnish  but  little  material 
that  is  fit  for  an  investigation  of  these  delicate  bodies.  This  unfortunate 
state  of  preservation  is  well  known  to  collectors  and  also  strongly 
prevalent  in  the  graptolitiferous  shale  region  of  New  York,  the  greater  part 
of  which,  namely,  the  entire  territory  bordering  on  and  east  of  the  Hudson 
lies  within  the  region  which  has  been  subject  to  the  Appalachian  folding. 
Hence,  while  there  are  graptolite  localities  of  most  zones  in  large  number, 
very  few  furnish  satisfactory  material. 

In  this  slate  or  shale  the  specimens  are  as  a  rule  flattened  to  such  a 
degree  that  but  very  faint  relief  is  shown,  and  the  graptolite  has  become 
nothing  but  a  tenuous  film.  The  keenest  and  best  trained  observers,  as 
Barrande,  Hall  and  Lapworth,  notwithstanding  untiring  efforts,  have  there¬ 
fore,  been  unable  to  arrive  at  a  correct  conception  of  the  structure  of  the 
stipes  of  some  of  the  most  common  forms,  such  as  Diplograptus,  from  the 
study  of  shale  material. 

But,  as  if  to  atone  for  this  failure  to  furnish  structural  details,  the  shale 
preserves  the  outlines  and  general  form  of  the  multiplicity  of  types  distinctly 
and  in  very  accessible  state,  sometimes  even  retaining  the  entire  compound 
colonies  neatly  spread  out  on  the  bedding  planes ;  and  often  there  are  stored  in 
it  myriads  of  various  growth  stages,  which  are  so  well  preserved  that  one  is 
at  times  able  to  retrace  the  entire  ontogenic  development  of  a  type,  as 
the  writer  has  done  in  the  cases  of  Diplograptus  foliaceus,  Gonio- 
graptus  thureaui  and  Dictyonema  flabelliforme. 


480 


NEW  YORK  STATE  MUSEUM 


Another  advantage  of  the  shale  material,  of  equal  importance  to  the 
stratigrapher  and  the  student  of  the  phylogeny  of  the  graptolites,  is  the  fact 
that  the  graptolite  shales,  being  slow  deposits,  frequently  contain  rapidly 
changing  graptolite  faunas  within  a  very  limited  thickness  of  rock,  as  in  the 
Deep  kill  section  which  has  furnished  the  principal  material  for  this  memoir. 

As  stated  before,  the  flattened  shale  material  allows  the  elucidation  of 
but  very  meager  facts  bearing  on  the  internal  structure  of  the  graptolites. 
Sometimes,  however,  these  bodies  became  centers  of  crystallization,  mostly  of 
pyrite,  and  have  thus  been  protected  from  flattening  and  crushing  forces. 
Such  pyritized  specimens  have  been  used  for  the  preparation  of  sections 
by  Tornqnist  [see  p.476].  A  layer  of  graptolite  bed  2  in  the  Deep  kill 
section  contains  numerous  pyrite  nodules,  mostly  with  specimens  of 
Phyllograptus  ilicifolius;  and  the  writer  has  been  able  to  obtain 
from  thin  sections  of  these,  certain  facts  as  to  the  structure  of  the  stipes  and 
of  their  periderm. 

The  best  results,  however,  have  been  acquired  by  the  study  of  the 
graptolites  which  are  sometimes  found  embedded  in  limestone,  calcareous 
shale  or  chert.  By  means  of  sections  uncompressed  specimens  which  were 
preserved  in  more  or  less  calcareous  beds,  have  been  studied  by  Perner 
(Monograptus  and  Retiolites),  Giirich  (also  Monograptus)  and  by  Holm 
(Phyllograptus) . 

In  calcareous  or  flinty  beds  the  graptolites  can  be  further  etched  out 
with  acids  without  crumbling  to  pieces,  as  those  of  argillaceous  shale  will 
do  under  such  treatment.  This  method  was  first  applied  by  Gtimbel  [1878], 
but  has  been  brought  to  great  perfection  by  Holm  and  specially  by  AViman.1 

Limestone  material  was  found  the  simplest  to  handle,  and  muriatic  acid 
in  different  states  of  solution  or  milder  solvents  such  as  acetic  acid,  gave  good 

1  Dr  AViman  has  published  an  interesting  account  of  his  preparative  methods  in  his 
paper  “  Uber  die  Graptoliten  ”  [1895]  and  in  the  “  Structure  of  the  Graptolites”  [1896]. 
His  work  has  been  reviewed  in  the  American  Geologist  [1896]  by  Clarke,  and  in  the 
American  Naturalist  [1898]  by  Ruedemann. 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


481 


results  in  dissolving  the  matrix.  Strongly  argillaceous  marl  slates  were  first 
treated  with  acetic  acid,  which  dissolves  the  lime  content,  and  then  the 
graptolites  were  brought  out  with  hydrofluoric  acid.  In  silicious  rocks,  mostly 
chert  masses,  graptolites  have  been  freed  with  concentrated  hydrofluoric  acid. 

The  isolated  graptolites  have  been  decolored  by  Holm  and  Wiman  in 
different  ways.  Wiman  used  first  Schultze’s  maceration  medium,  which  is  a 
solution  of  calcium  chlorate  in  nitric  acid,  but  later  substituted  for  it  eau  de 
Javelle  or  potassium  hypochlorite,  because  Schultze’s  medium  is  often  too 
harsh.  The  specimens  were  then  cleared  with  chloroform  or  other  clearing 
fluids  and  mounted  in  Canada  balsam.  Where  this  method  could  not  be 
used  on  account  of  the  thickness  of  the  periderm,  they  were  prepared  for  the 
microtome  according  to  the  methods  used  by  zoologists. 

The  methods  of  illustration  of  graptolites  have  also  been  gradually 
improved.  Minute  isolated  specimens  and  thin  sections  have  been  drawn 
with  the  camera  lucida  by  Holm  and  Wiman  and  thus  accurate  representa¬ 
tions  obtained.  As  the  specific  distinctions  of  the  graptolites  have  frequently 
to  be  sought  in  minute  details,  such  as  the  inclination  and  closeness  of 
arrangement  of  thecae,  the  former  method  of  free-hand  drawing  with  its 
unavoidable  idealization  of  the  figures,  is  no  longer  sufficient  to  bring  out  the 
crucial  characters  with  the  desired  accuracy.  Fortunately  the  shale  material 
as  a  rule  retains  just  enough  relief  to  permit  its  being  drawn  with  the  camera 
hicida  or  even  being  photographed  as  Barrois  has  done.  Van  Ingen  has  also 
successfully  photographed  graptolites  of  the  St  John  group  and  then  used  the 
photograph  for  tracing  [Matthew  1895].  By  his  kind  assistance  I  have  been 
enabled  to  bring  out  characters  photographically  which  were  visible  to  but 
few  observers. 

Lapworth  has  had  constructed,  for  the  illustration  of  the  British 
graptolites  in  the  monograph  now  under  preparation,  a  horizontal  microscope 
with  attached  camera  lucida.  By  means  of  this  arrangement  the  specimens 
can  be  enlarged  with  the  least  possible  slanting  to  five  times  natural 
size.  The  drawings  have  then  been  shaded  and  reduced  by  photographic 


482 


NEW  YORK  STATE  MUSEUM 


process.  The  collotype  plates  thus  obtained,  miss,  it  is  true,  the  artistic  effect 
that  so  distinguishes  the  former  illustrations  of  graptolites  and  specially  the 
beautiful  engravings  in  Hall’s  Graptolites  of  the  Quebec  Group ,  but  they  are 
clearly  faithful  representations  of  the  specimens  in  natural  size. 

As  our  facilities  did  not  permit  us  the  application  of  Lapworth’s  method, 
which  would  appear  to  furnish  the  most  satisfactory  results,  we  have  drawn 
the  outlines  of  all  forms,  which  are  enlarged  by  means  of  a  vertically  placed 
compound  lens  with  attached  camera  lucida,  the  light  being  furnished  by  a 
Bausch  illuminating  lens.  This  arrangement  necessitated  very  little  slanting 
of  the  slabs,  and  the  slight  distortion  produced  by  the  inclined  position  of  the 
slabs  has  been  reduced  to  a  minimum  by  the  placing  of  the  longitudinal 
axis  of  the  fossil  in  a  diagonal  position.  These  outlines  have  been  reduced  - 
by  photography  to  a  scale  of  mostly  twice  natural  size,  this  small  enlargement 
being  retained  to  secure  more  distinct  representation  of  certain  details 
than  the  natural  size  drawings  could  furnish.  The  text  drawings  are 
slightly  reduced  camera  drawings.  The  illustrations  in  natural  size  have  been 
traced  with  a  lithographer’s  needle  directly  from  the  fossils  on  gelatin  plates, 
glued  over  the  graptolites.  After  retracing  on  the  other  side  of  the  gelatin 
plate,  the  outlines  have  been  transferred  to  paper  by  means  of  lampblack, 
rubbed  into  the  tracings.  While  this  method  can  not  give  exact  results  with 
minute  objects  and  hence  is  subject  to  various  sources  of  error,  it  not  only 
gives  satisfactory  results  with  larger  fossils,  but  also  saves  much  time  and 
labor. 

4  Terminology 

The  terminology  which  is  currently  applied  to  the  graptolite  structure 
has  been  transferred  to  this  extinct  class  from  the  hydrozoans  under  the 
assumption  that  the  graptolites  form  a  branch  of  the  Cnidarians.  This  usage 
can  be  objected  to  on  the  ground  that  the  taxonomic  relations  of  the  grap¬ 
tolites  are  not  yet  established.  It  seems  however  that,  inasmuch  as  a 
terminology  is  necessary,  and  the  graptolites  indeed  in  their  structure  show 
more  analogies  and  similarities  to  the  Hydrozoa  than  to  any  other  class  of 
living  animals,  a  leaning  toward  the  hydrozoan  terminology  appears  most 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


483 


practicable,  while  the  presence  of  distinctive  features  makes  the  creation  of 
certain  new  terms  imperative. 

As  numerous  terms  have  been  applied  to  almost  every  part  of  the 
graptolite  structure,  it  is  advisable  to  define  the  terms  here  used  before 
entering  on  a  description  of  the  forms  and  a  discussion  of  their  structure. 

The  term  hydrosome  means  “the  whole  colony”  in  the  terminology  of 
the  hydrozoans.  For  the  whole  colony  of  the  graptolites  the  terms  frond, 
polypary ,  polypidom,  polypier ,  polypariet ,  colonie  and  Stock  also  have  been 
used.  Tornquist  has  proposed  to  use  for  hydrosome  the  more  neutral  term 
rhabdosome ,  which  has  been  adopted  by  Wiman.  The  rhabdosome  of  a 
graptolite  could  be  defined  as  each  colony  which  originates  from  a  sicula. 
Here  arises,  however,  a  difficulty  from  the  fact — discussed  fully  in  the 
chapters  on  embryology  and  morphology  of  the  graptolites  —  that,  while  in 
the  Dendroidea  and  Dichograptidae  each  colony  originates  from  one  sicula,  in 
the  later  forms,  the  Axonophora  (Diplograptus  etc.)  generations  of  secondary 
colonies,  produced  by  the  primary  colony,  and  each  of  which  also  originates 
from  a  sicula,  remain  in  connection  with  the  mother  colony  and  thus  form  a 
compound  colony  or  a  person  of  a  still  higher  order  (the  bushlike  stocks 
of  Diplograptus  etc.).  These  are  hence  colonies  of  colonies,  or  a  combination 
of  rhabdosomes.  It  would  probably  be  advantageous  to  apply  to  these  com¬ 
bination  colonies  a  term  like  synrhabdosome,  expressive  of  their  composite 
character.1  As  formerly  the  “  stipes  ”  (rhabdosomes)  of  Diplograptus, 
Climacograptus  and  other  later  genera  were  considered  as  representing  the 
whole  colony,  the  terms  hydrosome,  rhabdosome,  polypariet  etc.  have  been 
applied  to  these  as  well  as  to  the  entire  colonies  of  the  Dichograptidae  and 
Dendroidea.  This  usage  happens  to  be  correct  in  consequence  of  the  homology 
of  both  now  recognized. 

1  The  writer  has  in  a  previous  paper  on  Diplograptus  [1895,  p.  221]  termed  the 
compound  colonies  of  Diplograptus  hydrosomes  and  the  component  colonies  rhabdosomes, 
a  usage  which,  however,  does  not  appear  to  express  the  homology  existing  between  the 
components  of  the  Diplograptus  colony  and  the  whole  colony  of  the  Dichograptidae. 


484 


NEW  YORK  STATE  MUSEUM 


Freeh  proposes  to  reject  both  terms,  hydrosome  and  rhabdosome,  hitherto 
in  use  for  these  stipes,  as  indicating  that  the  latter  embrace  the  whole  organism, 
and  to  use  instead  the  term  liydrorhabd.  This  term,  again,  is  open  to  the 
objection  that  it  suggests  the  hydrozoan  nature  of  the  graptolites.  The  term 
polypary,  still  in  common  use  (also  in  Monograph  of  the  British  Graptolites) 
implies  the  close  taxonomic  relation  of  the  graptolites  to  the  Cnidaria.  We 
shall  for  this  reason  here  use  the  term  rhabdosome  for  the  colony  originating 
from  a  sicula  and  synrhabdosome  for  the  compound  colony  of  the  later  forms. 
The  rhabdosomes  are  persons  of  the  second  order,  being  composed  of 
thecae  (or  persons  of  the  first  order),  and  the  synrhabdosomes  are  persons  of 
the  third  order,  being  composed  of  those  of  the  second  order. 

The  single  hollow  cone,  from  which  the  rhabdosome  proceeds,  was 
originally  termed  the  radicle  or  initial  point  (ex  parte).  Fuss  and  Haftorgan. 
Lap  worth  has  introduced  the  term  sicula  for  it.  Holm  termed  it  the  first 
theca. 

Tornquist  and  Wiman  have  applied  the  term  connecting  canal  to  that  part 
of  the  first  theca  which  connects  the  sicula  with  the  common  cavity  of  the 
rhabdosome.  Holm  calls  the  proximal  part  of  the  second  theca,  which  crosses 
the  sicula,  the  connecting  canal.  Elies  and  Wood  call  this  part  the  crossing 
canal. 

That  aspect  of  the  rhabdosome,  in  which  the  sicula  is  visible  in  its  entire 
length,  is  termed  the  obverse  aspect  ( Siculaseite ),  the  other,  in  which  it  is  more 
or  less  covered  by  the  connecting  canal,  the  reverse  aspect  (. Antisiculaseite ). 
That  end  of  the  rhabdosome  which  contains  the  sicula  is  most  practically  termed 
the  sicula r  end,  instead  of  proximal  end,  and  the  other  the  antisicular  end. 

The  rhabdosome  of  most  graptolites  divides  into  branches.  These 
branches  are  known  as  branches ,  stipes,  Arme,  Zweige  and  Grenarne.  We 
call  here  forms  with  many  branches  multiramous,  forms  with  few,  pauci- 
ramous.  Forms  in  which  the  thecae  are  arranged  in  one  series  were  called  by 
Barrande  and  later  writers  monoprionidian ;  those  in  which  they  are  arranged 
in  two,  diprionidian. 

There  has  prevailed  much  difference  of  opinion  in  regard  to  the  proper 


GRAPTOLITES  OF  NEW  YORK.  PART  ] 


485 


Reclined  series 


Horizontal 


Declined  series 
Dependent  series 


Fig.  1  Diagrammatic  figure,  showing  the  relative 
angles  of  divergence  of  the  branches  characteristic  of 
the  several  series  of  Didymograpti  [Copied  from 
Lapworth,  Elies  &  Wood] 


conception  of  the  angle  of  divergence  of  the  branches.  The  fact  of  the 
gradual  reversion  of  the  branches  from  a  descending  to  an  ascending  position 
is  readily  expressed  by  the  use  of  Hopkinson’s  definition  of  the  angle  of 
divergence  as  the  “angle  included  within  the  polypiferous  margins  of  the 
branches.” 

The  variation  of  the  angle  of  divergence  and  of  the  curves  described  by 
the  branches,  has  made  it  expedient 
to  introduce  terms  for  a  number  of 
characteristic  positions  of  the  branches, 
which  will  save  long  descriptions. 

These  are  dependent ,  declined ,  deflexed , 
horizontal,  reflexed,  reclined  and  recum¬ 
bent  branches.  The  terms  find  their 
explanation  in  the  appended  diagram. 

A  difference  has  been  noted  be¬ 
tween  dichotomous  and  monopodial 
[Wiman]  or  lateral  [Elies]  branching.  In  the  first  both  diverging  mother 
thecae  of  the  new  branches  assume  directions  different  from  that  of  the 
older  branch,  while  in  the  monopodial  branching  only  one  mother  theca  of  a 
new  branch  turns  aside.  Where  repeated  divisions  produce  numerous  genera¬ 
tions  of  branches,  the  self-explaining  terms,  branches  of  the  first,  second,  etc. 
order ,  are  used  to  denominate  the  successive  generations. 

The  receptacles  of  the  zooids  passed  originally  under  the  designations, 
denticles ,  calycles,  cellules ,  cells,  cups  and  Zdhne,  and  were  later  on  called 
hydrothecae  like  the  analogous  parts  of  the  hydrozoans.  At  present  the  term 
thecae ,  ( Theken ,  lliekorna )  has  found  nearly  universal  usage.  Lapworth  has 
lately  used  the  term graptothecae  [1897,  p.251].  Frequently  the  zooids,  which 
once  inhabited  the  thecae,  are  meant  by  the  expression  thecae,  a  usage  which, 
though  illogical,  can,  as  Holm  has  pointed  out,  hardly  be  avoided,  if  long 
paraphrases  are  not  to  be  used.  As  a  matter  of  fact,  the  shells  are  in  paleon- 
tologic  literature  currently  treated  as  the  individuals.  The  thecae  represent 
the  persons  of  the  first  order. 


486 


NEW  YORK  STATE  MUSEUM 


The  distal  end  of  the  theca  is  the  aperture.  In  describing  the  thecae, 
one  regards  them  as  bounded  by  four  walls,  viz  one  dorsal  (inner),  one  ventral 
(outer),  and  two  lateral  walls.  The  distal  free  margins  of  these  walls  consti¬ 
tute  collectively  the  apertural  margin.  The  ventral  region  of  the  apertural 
margin  forms  a  well  marked  denticle  and  is  sometimes  prolonged  into  an 
apertural  spine.  The  length  of  the  thecae  is  conventionally  measured  by  the 
ventral  margin.  The  latter  is  in  contact  with  the  dorsal  wall  of  the  theca 
immediately  preceding  it,  or  overlapped  by  it  to  a  certain  fraction  of  the  length 
of  the  thecae. 

The  walls  of  the  rhabdosomes,  which  in  the  living  state  were  chitinous, 
are  cited  as  the  periderm ,  perisarc ,  test,  Haut  and  Schale. 

The  proximal  parts  of  the  thecae  form  a  canal  in  the  Graptoloidea.  This 
is  termed  the  common  canal ,  coenosarcal  caned ,  gemeinsamer  Canal ,  canal 
commun.  The  outer  edge  of  this  common  canal  is  termed  the  dorsal  edge.  A 
view  of  the  compressed  stipes,  in  which  only  this  canal  is  exhibited,  is  a  dorsal 
view.  The  opposite  margin,  which  is  denticulated  by  the  outer  margins  of  the 
thecae,  is  the  ventral  margin,  and  the  corresponding  view  is  the  ventral  or 
frontal  view  (scalariform  aspect).  In  the  profile  view  both  the  dorsal  and 
ventral  edges  are  seen. 

Hall  proposed  the  term  funicle  for  the  central  connecting  process  and  its 
subdivisions  in  the  Dichograptidae,  which  he  thought  to  be  destitute  of  thecae. 
Since,  however,  these  central  parts  have  later  on  turned  out  to  be  also  -com¬ 
posed  of  thecae,  the  term  is  no  longer  applicable  to  them.  The  writer  [1895, 
p.222]  had  applied  Hall’s  term  to  the  small,  long  elliptic  chitinous  vesicle  from 
which  the  nemacauluses  of  Diplograptus  spring.  Wiman  [1895,  p.73]  has 
pointed  out  that  this  so  called  funicle  of  Diplograptus  is  a  different  part  of  the 
graptolite  colony  from  that  which  Hall  termed  funicle  in  the  Dichograptidae ; 
he  concedes  however  that  it  may  be  identical  with  the  part  of  Retiograptus 
called  funicle  by  Hall.  As,  indeed,  the  composition  of  the  synrhabdosomes  of 
Retiograptus  and  Diplograptus  is  identical,  both  representing  persons  of  the 
third  order,  and  the  central  parts,  termed  here  funicle,  are  stems  which  are 
destitute  of  thecae,  the  term  no  longer  necessary  for  the  Dichograptidae  could 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


487 


be  properly  transferred  to  them.  The  funicle  is,  then,  the  common  base  of  the 
nemacauluses  of  the  rhabdosomes  or  persons  of  the  second  order  in  the  Axon- 
ophora,  or  one  of  the  central  parts  of  the  person  of  the  third  order,  while  the 
“  funicle  ”  of  the  Dichograptidae  represented  but  the  central  part  of  a  person 
of  the  second  order. 

The  sicula  is  suspended  by  means  of  a  flexuous,  filiform  process  which  has 
been  termed  the  nema  or  lima  by  Lapworth  [1897,  p.251],  and  hydrocaulus 
by  the  writer  [1895,  p.224].  In  the  last  cited  paper  it  has  been  shown  that 
the  proximal  prolongation  of  the  axis  of  the  rhabdosome  of  Diplograptus 
known  as  virgula  is  identical  with  this  nema  or  hydrocaulus.  This  latter  is 
a  hollow  process,  capable  of  further  growth.  There  originates  however  in  the 
wall  of  the  sicula  of  the  Axonopliora,  as  Wiman  has  demonstrated,  a  solid 
rod,  to  which  the  latter  author  has  applied  the  name  virgula.  This  rod  is 
not  present  in  the  sicula  of  the  Axonolipa,  and,  as  the  writer’s  observation 
would  indicate  [1897,  pl.2,  fig. 6],  it  extends  into  the  nema  of  the  Axonopbora. 

A  sharp  distinction  between  the  hollow  proximal  prolongation  of  the 
sicula,  present  in  all  Graptoloidea,  and  the  solid  axis,  originating  in  the  wall 
of  the  sicula  of  the  Axonophora  and  probably  extending  into  the  first  named 
prolongation,  hence  becomes  necessary.  For  this  reason,  the  writer  had 
proposed  to  name  the  hollow  process  hydrocaulus  and  the  solid  axis  the 
virgula.  As  the  term  hydrocaulus  is-' however  taken  from  the  Hydroidea, 
where  it  represents  an  analogous  process,  connecting  the  first  receptacle  of  the 
embryo  and  the  disk  of  attachment  [see  ch.7,  p.523],  it  appears  practical  to 
discard  it  for  one  of  the  neutral  terms,  nema  or  nemacaulus ,  proposed  by 
Lapworth.  The  term  nema  would  well  express  the  flexuous  character  of  this 
organ  in  the  Axonolipa,  and  the  term  nemacaulus  the  more  rigid  character  in 
the  Axonophora. 

In.  certain  Dichograptidae  the  bases  of  the  stipes  are  “  united  by  a 
thickened  corneous  expansion  ”  which  was  termed  by  Hall  the  central  disk. 
The  writer  has  observed  a  chitinous  disk  in  the  early  stages  of  various  forms 
[see  ch.7,  p.535],  from  which  the  sicula  is  suspended.  This  we  call  here  the 
'primary  disk,  as  it  is  clearly  a  more  or  less  essential  part  of  the  first  growth 


488 


NEW  YORK  STATE  MUSEUM 


stage  coining  under  notice.  The  disk  forming  the  center  of  the  synrhabdosome 
of  Diplograptus  is  a  further  development  of  this  primary  disk  and  should, 
hence,  not  have  been  termed  a  “  central  disk,”  as  was  done  on  a  former  occasion 
by  the  writer. 

Basal  cyst  or  pneumatocyst  has  been  applied  to  a  tenuous  chitinous 
vesicle,  observed  in  Diplograptus  by  the  writer,  which  is  supposed  to  have 
served  as  a  “  float.” 

Dendroidea  Nicholson.  This  term  embraces  the  dendroid  graptolites. 

G r apt olo idea  Lapwortk.  These  are  the  graptolites  proper. 

Retioloidea  Lapwortk.  In  this  group  the  periderm  consists  of  a  network 
of  chitinous  filaments. 

Axonolipa  Freeh.  In  this  order  the  virgula  or  solid  axis  is  lacking. 

Axonophora  Freeh.  The  forms  ot  this  order  are  provided  with  a  virgula. 

5  Range  and  geographic  distribution 

The  graptolites  begin  with  a  few  undoubted  forms  in  the  closing  stage  of 
the  Cambric,  attain  their  acme  in  the  Champlainic  (Lower  Siluric),  reach  a 
second,  minor  period  of  prosperity  with  a  small  group  of  newly  developed 
genera  in  the  lower  and  middle  Siluric  and  disappear  with  astonishing 
rapidity  in  the  Upper  Siluric,  leaving  but  a  few  stragglers  (four  species  in 
North  America)  in  the  Devonic. 1  For  this  reason  they  can  be  considered  a 
class  of  organisms  most  characteristic  of  the  Champlainic  and  Siluric  eras. 

During  the  period  of  their  greatest  vitality  they  attained  a  remarkable 
rapidity  of  development,  which  has  permitted  the  division  of  the  graptolite 
shales  of  several  regions  into  a  great  number  of  life  zones.  This  is  notably 
the  case  in  certain  parts  of  Sweden,  where,  for  instance,  Tullberg  cites  from 
Scania  [1882]  no  less  than  26  graptolite  zones  of  the  Lower  and  Upper  Siluric. 
This  fact,  together  with  the  discovery  brought  out  by  investigations  in 
Great  Britain,  France,  America  and  Australia,  that  the  larger  divisions 

hurley  has  also  described  a  fossil  from  the  Choteau  limestone  (Carboniferous)  of 
Sedalia  Mo.  as  Dictyonema  blairi.  This,  however,  is  very  doubtful  and  according 
to  last  accounts  only  the  remains  of  a  plant. 


Chart  of  the  World  showing  the  Distribution  of  the  Lower  Graptolite  Faunas 


North 


Legend 

Land  areas  at  the  beginning  of  the  Champlain  (Lower  Siluric)  era  in  drab  tint;  their 
boundaries  copied,  with  some  alterations,  from  Freeh  [1897] 

5  Localities  of  zone  with  Dict.yonema  flabelliforme 

•  “  “  Tetragraptus-Phyllograptus  zones  (zones  1  and  2  of  Deep  kill  section) 

+  “  “  zone  with  Diplograptus  dentatus  (zone  8  of  Deep  kill  section ) 

*  “  “  Goniograptus  thureaui 


♦x- 


GKAPTOLITBS  OF  NEW  YORK,  PART  1 


489 


can  be  recognized  over  immense  areas,  has  given  to  the  graptolites  their 
well  known  reputation  as  reliable  indicators  of  homotaxial  beds.  It  is  the 
merit  of  Linnarsson,  Tornquist  and  Tullberg  in  Sweden,  and  of  Lapworth  in 
Great  Britain  to  have  brought  into  general  recognition  the  fact  of  the  possible 
correlation  of  the  graptolite  beds  in  different  regions,  and  of  their  subjection 
to  the  general  law  of  progress  and  development  of  the  organic  world,  and 
thus  to  have  freed  them  from  the  bane  of  suspicion  which  the  theory  of 
colonies,  promulgated  by  Barrande,  had  brought  on  all  correlation  by 
graptolites. 

The  elaboration  of  the  European  graptolite  faunas  has  shown  that  the 
graptolites,  in  their  development,  have  three  times  in  succession  changed  their 
plan  of  structure  and  thus  produced  three  large  divisions,  by  which  also  the 
zones  can  be  divided  into  three  large  stratigraphic  divisions.  These  are  that 
of  the  deeper  Lower  Siluric,  which  is  characterized  by  the  Dichograptidae, 
or  uniserial  forms  without  axis;  the  higher  Lower  Siluric,  in  which  the 
biserial  forms  with  axes,  the  Climacograptidae  and  Diplograptidae,  impress 
their  character  on  the  faunas ;  and  that  of  the  Upper  Siluric,  in  which  the 
Monograptidae,  the  uniserial  forms  with  axes,  hold  the  field  almost  to  the 
exclusion  of  all  other  forms. 

Of  these  the  two  first  divisions  are  well  represented  in  the  graptolite 
fauna  of  New  York.  The  faunas  of  the  first  are  the  subject  of  the  present 
memoir,  while  those  of  the  second  division,  which  find  their  typical 
representation  in  the  Normanskill  fauna,  will  be  treated  in  a  succeeding 
publication.  The  third  division,  so  richly  developed  in  many  parts  of  Europe, 
as  Sweden,  Great  Britain,  Bohemia  and  France,  is  hardly  more  than  suggested 
by  a  few  species  found  in  the  Clinton  shales. 

To  the  correlation  of  the  North  American  graptolite  horizons  with  the 
European  zones  on  one  hand  and  with  the  standard  formations  of  this  State 
on  the  other,  but  little  attention  has  thus  far  been  paid.  The  difficulties  here 
are  of  the  same  character  as  those  with  which  Nicholson,  Lapworth,  Man*  and 
others  have  had  to  contend  in  Great  Britain,  namely  an  indescribable  confusion 
of  the  beds  by  extensive  orogenic  movements  of  this  part  of  the  earth  crust. 


490 


NEW  YORK  STATE  MUSEUM 


For  English  as  well  as  American  geologists,  therefore,  the  Swedish  beds, 
which  are  found  in  undisturbed  or  slightly  altered  position,  must  remain  the 
standards  of  succession. 

The  identity  of  a  considerable  number  of  forms  from  the  Arenig  beds  of 
the  Lake  district  in  north  England  and  of  Wales  with  species  described  by 
Hall  from  the  Quebec  beds,  and  of  English  Llandeilo  graptolites  with  those 
of  the  Normanskill  fauna,  was  early  recognized,  and  these  American  terranes, 
accordingly,  roughly  correlated  with  English  formations. 

Regarding  the  succession  of  the  minor  divisions  of  the  known  graptolite 
terranes  of  eastern  North  America  there  prevailed,  however,  in  consequence  of 
their  disturbed  position,  certain  wrong  conceptions ;  and  these,  having  received 
Hall’s  authoritative  confirmation,  enjoyed  for  a  long  time  an  unhesitating 
acceptance.  One  of  these  was  the  placing  of  the  “  Hudson  river  shales  ”  as  a 
mass  with  their  Normanskill  and  other  faunas  in  the  uppermost  Lower  Siluric, 
above  the  Utica  shales. 

When  Lapworth  [1886]  was  given  an  opportunity  to  study  a  collection 
from  various  localities  in  Canada,  he  recognized  in  them  the  Cambric  Dictyo- 
nema  zone,  the  Pliyllograptus  anna  zone,  the  Normanskill  zone  and 
the  Utica  zone,  and  by  reference  to  the  succession  of  the  zones  in  Europe  he 
asserted  that  the  Phyllograptus  zone  must  correspond  to  a  part  of  the  lowest 
Lower  Siluric,  and  the  Normanskill  zone  should  be  placed  provisionally 
between  the  Chazy  and  Ti’enton,  at  any  rate  below  the  Utica.  Ami  [1890] 
inclined  to  a  similar  correlation  of  the  Normanskill  shale  on  account  of  its 
association  with  rocks  of  apparently  Lower  Trenton  aspect  in  the  Quebec 
fault  block;  and  Gurley,  after  an  investigation  of  the  North  American 
graptolites,  concluded  that  “the  vertical  succession  of  the  American  graptolites 
represents  a  complete  parallel  to  the  range  in  other  countries.” 

The  present  writer  has  shown  [ l 901]  that  in  the  so  called  “Hudson  river 
shales  ”  of  the  neighborhood  of  Albany  there  can  be  discerned  a  number  of 
faunal  zones,  running  parallel  to  the  strike  of  the  beds,  from  which  the 
succession,  in  ascending  order,  of  the  Normanskill  fauna,  the  Utica  and 
Lorraine  faunas  with  several  transitional  faunules  can  be  established  [see 


CORRELATION  TABLE  OF  THE  ZONES  IN  THE  CAMBRIC  AND  CHAMPLAINIC  (LOWER  SILURIC)  OF  THE  SLATE  BELT  OF  NEW  YORK 


Forma¬ 

tion 


Slate  belt  of  New  York 


Canada 


<D 


03 

£ 

o 

►J 


oJ 

2  j 


-u 

p 


Zone  with  Dipl,  f  o  1  i  a  c  e  us, 
Cory  n.  curt  us  and  Lor¬ 
raine  fossils  (Waterford) 


Zone  with  Dipl,  q  u  a  d  r  i 
mucronatus,  D.  folia- 
ceus,  D.  pusillus, 
Coryn.  curtus,  Triar- 
thrus  becki  etc.  (Rural 
cemetery,  etc.) 

Transitional  zone  with  C  1  i  m  a  - 
cogr.  caudatus,  Cryp 
togr.  tricornis,  Triar- 
thrus  becki  etc.  (Mechan¬ 
ic  icville,  Van  Schaick  island) 

?  Upper  Dicellogr.  zone  (Lans 
ingburg  power-house) 


Great  Britain 


,orraine  beds 


Utica  beds  with  Dipl 
quadrimucronatus 
(Quebec  etc.)  and  Lep- 
togr.  flaccid  us  (Lake 
St  John) 


Zone  with  Dipl,  a  tuple  xi- 

e  ■{  c  a  u  1  i  s  (Troy) 

© 

Ut 

Lower  Dicellogr.  zone  (Nor- 
manskill  beds) 


l 


Upper  Dicell,  zone  (Quebec 
and  Magog,  Gurley) 
(=  zone  without  Coe- 
nogr.  gracilis  Lapw.) 


Lower  Dicell,  zone  (Quebec 
etc.  Gurley)  (=zone  with 
Coenogr.  gracilis 
Lapworth) 

Beds  of  Mystic  (Gurley) 


N 

c5 


2 


o 


a 

s? 

o 

c 

£ 

CJ 

© 


Zone  with  Dipl,  dentatus 
and  Cryptogr.  anten- 
,  n  ar  i u  s  (Deep  kill) 

[  Transitional  subzone(Mt  Moreno) 
"Zone  with  Didymogr.  bifi- 
dus  and  Phyllogr.  anna 
(Deep  kill) 


a  Zone  with  Tetr.  (Deep  kill) 
subz.  b  Goniogr.  subzone 
“  a  Clonogr.  subzoue 


Point  Levis  zone  (Gurley) 


St  Anne  zone  (Lapworth 
and  Gurley)  Graptolite 
shales  of  Newfoundland 
Division  P  (Billings) 


Top  of 


Zone  with  Dictyonema  fla- 


Upper  belliforme  (Schaghticoke 

Cambric  etc.) 


Main  Point 
(Gurley) 


Levis  zone 


© 
o 
ra 

2  ^ 
cS 

Q 


Zone  with  Dicell,  an- 
ceps  (Upper  Hartfell 
shales)  upper  Caradoc  of 
Shropshire  with  Dipl, 
foliaceus  etc. 

Zone  with  Dicell,  com- 
p  1  a  n  a  t  u  s  (Upper  Hart- 
fell) 


Zone  with  Pleurogr.  lin¬ 
earis,  Dipl,  quad¬ 
rimucronatus,  etc 
(Lower  Hartfell) 

Zone  with  Dicranogr, 
c  1  i  n  g  a  n  i  (Lower  Hart 
fell) 

Zone  with  Climacogr. 
w  i  1  s  o  n  i  (Lower  Hart¬ 
fell  shales,  Moffat  etc.) 
f  Zone  with  Coenogr. 
gracilis  (Lapworth) 
Lowest  Moffat  beds, 
Glenkiln  shales 


© 

'O 

a 

a 


© 

© 


Cambric  j  No  &™Ptolites 


Diet,  f  labellif  orme 
zone  Gaspe  (Lapworth), 
St  John  (Matthew) 


No  graptolites 


Ellergill  beds  (Elies)  (=  Llan 
virn,  Elies) 


Upper  Tet.  zone  (Skiddaw 
slates,  Elies)  Upper  Are- 
nig  beds  of  Scotland  and 
Wales 

Lower  Tet.  and  Dich.  zones 
(Skiddaw  slates,  Elies) 
Middle  Arenig  graptolite 
beds  of  Scotland  and 
Wales 


Scandinavia  (Tullberg) 


Zone  with  Dipl.  sp.  nov. 


Other  regions 


Zone  with  Dicell,  com 
planatus 


OQ 

CO 


© 

co 


© 


a, 

cS 

© 

£3 

T3 


Zone  with  Dipl,  quad 
rimucronatus 


Zones  with  Climacogr. 
vasae,  Dicranogr. 
c  1  i  n  g  a  n  i  etc. 


Zone  with 
gracilis 


Coenogr. 


Zones  with  Glossograp 
t  u  s  and  Didymogr 


gem inu  s 


© 


o 

-u> 

O.  „ 

cS  03 

S-S 

&  S 

£ 

o 


Diet,  flabelliforme  zone 
in  Upper  Lingula  flags  of 
Wales 


No  graptolites 


Zone  with  Phyllogr 
t  y  p  u  s  and  D  i  d  y 

mogr.  bifidus 


Tetragraptus  shales 


Upper  Maquoketa  shales  (Ohio 
and  Mississippi  valleys) 


Dd  5  of  Bohemia  with  Dipl 
pristis 


Lower  Cincinnati,  lower  Ma¬ 
quoketa  shales  (Ohio  valley) 


Shale  of  Gembloux  (Arden¬ 
nes)  with  Climacogr- 
caudatus,  C.  styloi- 
d  e  u  s ,  and  sandstone  of  St 
Germain-sur-lle  with  Dipl, 
foliaceus  and  D.  an- 
gustif  olius 
Shale  with  Coenogr.  gra¬ 
cilis  of  Victoria,  Aus¬ 
tralia.  Shales  of  Arkansas 

%  Graptolite  shales  of  Kicking 
Horse  pass,  and  Dease  river, 
British  Columbia  (Gurley) 
%  shales  of  Nevada 
Graptolite  shales  of  Arkansas 
and  Nevada 


Shales  of  Cabrieres,  France. 
Dd  1  of  Bohemia  with 
Didymogr.  bifidus. 
Auriferous  shales  of  Vic¬ 
toria,  Australia 

Shales  of  Huy-Statte  and 
Sart-Bernard  (Ardennes) 
with  Phyllogr.  Dich.  and 
Tet.  Auriferous  shales  of 
Victoria,  Australia 


Diet,  flabelliforme  zone 
Christiania,  Scania,  Bornholm 
Oesel 


Diet.  flabelliforme 
zone  Esthonia  (Russia), 
Belgium 


No  graptolites 


No  graptolites 


I 


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GRAPTOLITES  OF  NEW  YORK.  PART  1 


491 


correlation  table  of  zones  in  New  York,  p. 575].  To  the  Trenton  were  referred 
tlie  typical  Normanskill  or  lower  Dicellograptus  fauna,  tbe  lower  Dicellograptus 
fauna  of  Mt  Olympus  at  Troy,  which  contains  some  differing  elements 
and  the  Diplograptus  amplexicaulis  fauna.  The  Utica  formation 
was  found  to  be  represented  by  four  different  faunal  associations:  that  of 
Mechanicville,  which  contains,  besides  the  typical  Utica  fossils,  Conularia 
trentonensis  and  Climacograptus  caudatus,  a  form  hitherto 
known  only  from  Europe  as  being  associated  with  the  equivalent  of  the 
Normanskill  fauna;  the  Utica  fauna  of  Van  Schaick  island,  which  has  Crypto- 
graptus  tricorn  is,  another  Normanskill  form,  as  an  element;  the  typical 
Utica  fauna  of  Rural  cemeter}q  etc.;  and  the  Upper  Utica. fauna  of  the  old 
Dudley  observatory  site,  etc.  The  first  two  faunas  are  evidently  transitional 
to  the  Trenton.  A  fuller  account  of  the  faunas  of  these  zones  and  a 
discussion  of  their  relations  to  European  faunas  will  be  given  after  a  renewed 
and  more  detailed  study,  in  a  subsequent  memoir. 

In  another  publication  [1902]  the  writer  has  announced  the  discovery  of 
the  Quebec  (Levis)  graptolite  fauna  at  the  Deep  kill  in  the  “  Hudson  river 
shales  ”  of  New  York,  and  of  its  division  into  three  well  defined  zones,  which 
in  their  faunal  constitution  exactly  correspond  to  the  homotaxially  successive 
European  zones.  These  zones  were  correlated  by  the  writer  with  the  Beek- 
mantown  or  Calciferous  beds  of  New  York,  the  uppermost  being  considered 
as  possibly  of  Chazy  age.  It  is  this  locality  at  the  Deep  kill  which,  yielding 
an  extremely  rich  fauna  in  an  exceptionally  excellent  state  of  preservation, 
has  furnished  the  larger  portion  of  the  material  for  this  memoir. 

As  we  have  in  the  paper  mentioned  given  a  full  account  of  the  Canadian 
and  European  equivalents  of  the  Deep  kill  zones  and  of  the  geographic 
distribution  of  the  faunas  represented  there,  we  refer  here  for  all  details  to 
that  publication  and  to  the  correlation  table  [p.575]  of  the  zones  and  the  table 
of  the  distribution  of  the  species,  appended  to  this  chapter,  restricting 
ourselves  in  this  place  to  a  short  characterization  of  the  zones. 

The  presence  in  New  York  State  of  the  Dictyonema  flabelli- 
forme  zone,  so  well  known  in  Europe  as  characterizing  the  upper  limit 


492 


NEW  YORK  STATE  MUSEUM 


of  the  Cambric,  has  also  been  announced  lately  by  the  present  writer  [1903], 
The  taxonomic  position  and  distribution  of  this  zone  —  also  found  in  “  Hudson 
river  shales  ”  —  has  been  discussed  in  detail  in  the  paper  mentioned.  It  will 
therefore  suffice  briefly  to  review  here  the  more  important  facts. 

a  Zone  with  Dictyonema  flabelliforme.  This  zone  has  been  found  by  the 
writer  to  be  very  well  exposed  at  the  falls  of  the  Hoosic  river  in  the  village 
of  Scliaghticoke,  Rensselaer  co.  N.  Y.  Its  fossils  are  finely  preserved 
in  the  beds  exposed  at  Schaghticoke,  and  complete  series  of  growth  stages 
of  the  characteristic  graptolites  [pl.l]  were  secured  at  this  locality.  Its 
lithologic  characters,  which  are  similar  to  those  of  the  Deep  kill  beds  of 
Beekmantown  age,  can  also  be  well  studied  at  the  falls,  but  the  adjoining 
formations  are  not  exposed  there.  The  characteristic  graptolites  of  the  beds 
are  Dictyonema  flabelliforme  Eichwald  and  Staurograptus 
dichotomus  Emmons  (Clonograptus  proximatus  Matthew), both 
in  several  varieties. 

The  limitation  of  the  graptolite  fauna  to  hardly  more  than  two  forms, 
the  first  representative  of  the  long  persistent  genus  Dictyonema  and  the 
second  a  pronounced  synthetic  form,  Staurograptus,  seems  to  be  everywhere 
characteristic  of  this  zone ;  for  in  Canada,  where  it  was  recognized  at  nearly 
the  same  time  by  Dawson  and  Lapworth  in  the  slates  trending  along  the 
south  shore  of  the  lower  St  Lawrence,  these  are  the  only  graptolites  cited. 
In  the  St  John  (N.  B.)  basin,  where  the  vertical  range  of  Dictyonema  has 
been  carefully  studied  by  Matthew,  these  are  the  principal  graptolites,  and 
the  species  of  Bryograptus  cited  are  probably  all  referable  to  one  of  these 
forms  [see  p.616]. 

In  Europe,  the  zone  is  considered  as  marking  in  Scandinavia,  where  it  is 
widely  distributed,  the  closing  stage  of  the  Cambric.  Here  also  Dicty¬ 
onema  flabelliforme  is  associated  with  a  species  of  Clonograptus  that 
is  similar  to  ours,  and  probably  also  with  a  few  representatives  of  Bryograptus, 
which  is  another  synthetic  genus.  The  Dictyonema  zone  has  been  further 
recognized  in  Esthland,  Oesel,  Bornholm,  Belgium,  Wales,  western  England 
and  Ireland.  Brogger  has  demonstrated  that  the  zone  is  also  in  Great 


GRAPTOEITES  OF  NEW  YORK,  PART  1 


493 


Britain  to  be  regarded  as  marking  the  boundary  between  the  Cambric  and 
Siluric  eras. 

From  the  material  collected  by  the  geologists  who  have  been  engaged,  in 
mapping  the  slate  belt  of  New  York  and  Vermont,  I  infer  that  both  D  i  c  t  y  - 
onema  flabelliforme  and  Staurograptus  dichotomus  are 
also  present  at  other  localities  in  the  slate  belt  of  New  York,  notably  in  the 
region  of  Granville  in  Washington  county  [ see  localities  under  Dicty- 
onema  flabelliforme,  p.601].  The  fact  that  almost  without  exception 
only  the  more  common  early  growth  stages  had  been  collected,  prevented  the 
recognition  of  the  presence  of  this  stratigraphically  important  zone  in  the 
slate  belt  by  the  paleontologist  of  that  survey.  Subsequent  investigation  of 
the  outcrops  of  the  horizon  in  Washington  county  by  the  present  writer  has 
brought  out  the  fact  that  the  Dictyonema  shale  is  found  infolded,  northward 
from  the  Hoosic  river  to  and  beyond  the  Vermont  boundary,  between  the 
Georgian  shales  and  slates  and  the  basal  rocks  of  the  Lower  Siluric,  notably 
the  thinly  bedded  limestones  and  intercalated  shales,  characteristic  of  the 
Beekmantown  graptolite  horizons  at  the  Deep  kill. 

There  is  no  doubt  that  the  zone  extends  into  Vermont,  for  Dicty¬ 
onema  flabelliforme  is,  for  example,  found  at  Fairhaven  Vt.  and 
probably  it  extends  northward  through  that  state  and  merges  into  the  belt  of 
Dictyonema  slates  skirting  the  south  shore  of  St  Lawrence  bay. 

An  interesting  fact  brought  out  by  the  presence  of  the  shale  with 
Dictyonema  flabelliforme  in  the  slate  belt  of  eastern  New  York, 
one  which  has  an  important  bearing  on  the  paleography  of  eastern  North 
America,  is  that,  while  the  contemporaneous  Upper  Cambric  or  Saratogian 
littoral  facies  of  New  York  —  the  Potsdam  sandstone,  Greenfield  limestone,  at 
Saratoga  etc.  —  by  their  included  Dicellocephalus  fauna  were  clearly  deposited 
in  the  American  Pacific  basin,  the  Atlantic  waters  encroached  close  by  on  the 
present  territory  of  the  slate  belt,  probably  along  the  “  Levis  channel  ” 
outlined  by  Ulrich  and  Schuchert,  for  the  earlier  Lower  Siluric.  [See 
appended  chart  on  the  distribution  of  the  fauna  with  Dictyonema 
flabelliforme. 


494 


NEW  YORK  STATE  MUSEUM 


b  Tetragraptus  zone.  This  zone  is  represented  at  the  Deep  kill  by 
two  graptolite  beds.  While  the  fauna  of  one  of  the  beds  is  largely  composed 
of  species  of  Didymograptus,  and  in  the  other  the  representatives  of  the  genus 
Tetragraptus  prevail,  a  comparison  of  the  faunal  lists  of  the  two  shows  that  all 
species  occurring  in  the  first  bed  are  also  found  in  the  second,  and  that  both 
comprise  one  fauna.  This  consists  of  32-  species  of  graptolites.  Of  these, 
16  are  restricted  to  this  horizon.  Of  the  remaining,  the  greater  majority 
extend  only  into  the  lowest  bed  of  the  next  horizon. 

The  most  important  genus,  which,  both  by  the  number  of  its  species  and 
its  individuals,  gives  to  this  zone  its  character,  is  the  genus  Tetragraptus,  of 
which  eight  species,  out  of  the  10  of  the  Deep  kill  section,  are  either 
restricted  to  this  zone  or  clearly  reach  here  the  acme  of  their  development. 
The  most  stately  and  showy  forms  of  the  genus,  asT.  quadribrachiatus, 
amii,  fruticosus,  serra  and  s  i  m  i  1  i  s,  are  those  found  in  this  bed. 
The  species  of  Tetragraptus  found  in  the  next  horizon  are  either  smaller 
mutations  of  these  species  or  dwarfed  species  with  distinct  paracmic  features. 

Next  in 'importance,  in  the  number  of  individuals  and  species,  is  the  genus 
Didymograptus,  which,  however,  is  represented  by  only  five  of  its  14  Deep 
kill  species  in  this  zone,  the  others  all  being  of  later  age.  These  five  species 
all  belong,  as  a  glance  at  the  synoptic  table  of  the  genera  [p.  508]  will  show, 
either  to  the  horizontal  or  to  the  declined  series.  The  dependent  (“  tuning 
fork  ”)  and  reclined  forms  are  still  entirely  absent.  The  horizontal  series  of 
Didymograptidae  culminates  in  this  zone  and  declines  at  its  termination, 
entering  the  next  zone  with  only  one  species. 

The  genus  Phyllograptus  is  represented  with  three  of  its  five  Deep  kill 
species  in  this  zone,  but  the  largest  and  most  typical  form,  P.  t  y  p  u  s ,  is  not 
developed  till  the  next  zone  is  reached. 

The  multiramous  Dichograptidae  are  represented  by  Dichograptus 
octobrac hiatus,  which  here  culminates ;  and  two  of  the  three  species  of 
the  genus  Goniograptus,  attain  here  their  greatest  size  and  frequency.  It  is 
however  to  be  noted  that  the  genus  Clonograptus,  so  well  represented  in  the 
Main  Point  Levis  zone,  is  absent  entirely  and  only  represented  by  its  more 
rigid  and  symmetric  descendant,  Goniograptus.  It  is,  hence,  very  probable 
that  the  Tetragraptus  zone  is  preceded  by  a  subzone  characterized  by  the 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


495 


Clonograpti,  which  is  either  not  exposed  or  not  represented  at  the  Deep  kill. 
On  the  other  hand,  the  upper  Cambric  synthetic  genus  Bryograptus  extends 
with  two  species  into  this  horizon,  thereby  indicating  the  proximity  of  the 
latter  to  the  beginning  of  the  graptolite  reign. 

Of  Dendroidea  we  find  the  genera  Dictyonema,  Dendrograptus  and 
Callograptus  represented  in  this  zone.  Finally,  the  species  of  Dawsonia 
and  Caryocaris,  described  in  this  paper,  were  also  obtained  from  the  same. 

The  correlation  of  this  zone  with  the  divisions  recognized  in  Canada  and 
Europe  has  been  fully  discussed  before  [1902].  For  this  reason  only  a  short 
summary  is  here  given. 

The  Tetragraptus  zone  of  the  Deep  kill  is  homotaxial  to  a  part  (probably 
upper  part)  of  the  beds  termed  by  Gurley  the  “  Main  Point  Levis  zone  ”  of 
the  Quebec  beds.  This  is  the  zone  containing  the  typical  Quebec  graptolite 
fauna.  The  same  zone  is  probably  present  at  St  John  N.  B.  [Matthew],  and 
at  Cow  Head,  Newfoundland  [Billings].  The  association  of  forms,  character¬ 
istic  of  this  horizon,  is  typically  developed  in  the  Middle  Skiddaw  slates  of 
the  Lake  district,  north  England  [Elies].  The  Dichograptus  bed,  which  there 
separates  the  lower  and  upper  Tetragraptus  bed,  is  probably  the  exact 
equivalent  of  the  zone  here  considered.  The  more  common  species  of  the 
Tetragraptus  zone  are  also  found  in  the  Arenig  shales  of  St  Davids,  Wales, 
of  the  Shelve  district  in  Shropshire,  west  England,  and  in  the  Ballantrae 
terrane  in  south  Scotland.  In  Sweden  [Tornquist  and  Tullberg]  the  fauna 
here  under  consideration  is  found  in  the  “ Tetragraptus  shales”  overlying 
the  Ceratopyge  limestone  and  succeeded  by  the  Orthoceras  limestone.  The 
latter  also  contains  in  Oeland  [Holm]  some  of  the  species  of  this  zone 
(Tetr  ag  rapt  us  bigsbyi  and  Pliyll.  an  gust  if  olius).  In  France, 
a  number  of  the  characteristic  species  of  Tetragraptus  and  Didymograptus 
have  been  found  in  the  graptolite  schists  of  Boutoury  near  Cabrieres  in 
the  Languedoc  [Barrois];  and  Dichograptus  o  c  t  o  b  r  a  c  h  i  at  u  s  is 
reported  from  Belgium  [Malaise].  In  Australia,  well  known  Levis  forms 
have  been  recoi’ded  by  McCoy  and  Etheridge  jr  from  various  localities  of 
Victoria. 


496 


NEW  YORK  STATE  MUSEUM 


Subhorizon  of  Clonograptus  cf.  flexilis  (Clonograptus  bed).  Tliei'e  OCCUFS  at  a  locality 

in  Rensselaer  county,  about  4^  miles  due  east  from  the  city  of  Albany,  in  a 
small  road  metal  pit  on  the  road  between  Defreestville  and  West  Sandlake, 
a  yellowish  weathering  sandy  slate,  interbedded  in  light  greenish  and  darker 
silicious  slates,  which  contains  a  faunule  that  indicates  the  presence  of  a 
subhorizon  of  the  Tetragraptus  beds  lying  below  the  first  graptolite  bed 
observed  at  the  Deep  kill. 

The  faunule,  which  was  discovered  by  Professor  Dale  (his  locality  154, 
the  material  being  in  the  National  Museum)  is  unfortunately  represented  by 
small  drifted  fragments  only,  and  the  present  writer  has  been  unable  to  secure 
more  favorably  preserved  material.  It  consists  of 


Dictyonema  murrayi  Hall .  c 

Clonograptus  cf.  flexilis  Hall .  cc 

Tetragraptus  quadribrachiatus  Hall .  c 

T.  serra  Brongniart .  c 

c=common  cc=very  common 


This  faunule  consists  of  two  species  of  Tetragraptus,  common  in  the 
Tetragraptus  zone  of  the  Deep  kill,  and  of  two  species  which  are  entirely 
absent  at  the  Deep  kill.  One  of  these,  Dictyonema  murrayi,  is 
recorded  by  Hall  as  occurring  “  in  hard  shales  ”  associated  with  Clono¬ 
graptus  r  i  g  i  d  u  s  and  two  other  very  robust  species  of  Dictyonema,  viz 
D,  irregularis  and  D.  robust  a.  There  appears,  hence,  also  in  the 
Quebec  region  an  association  of  a  Clonograptus  with  Dictyonemas  with 
remarkably  robust  rhabdosomes.  It  is  quite  probable  that  both  these 
faunules  represent  the  same  subhorizon,  the  exact  taxonomic  position  of 
which  is  at  present  unknown.  On  account  of  the  frequency  of  the  Clono- 
grapti,  this  subhorizon  is  however  to  be  considered  as  forming  a  part  of  the 
Clonograptus  beds  and  as  lying  in  the  lower  part,  or  perhaps  at  the  base,  of 
the  Tetragraptus  beds. 

C  Zone  with  Didymograptus  bifidus,  Phyllograptus  typus  and  Ph.  anna. 

This  zone  at  the  Deep  kill  comprises  a  considerable  thickness  of  rock, 
containing  numerous  graptolite-bearing  surfaces  which,  in  the  former  paper, 
were  divided  into  graptolite  beds  8,  4  and  5.  The  fauna,  consisting  of  28 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


497 


species,  is  still  entirely  composed  of  Dendroidea  and  Dichograptidae.  The 
prominent  genera  are  still  Tetragraptus,  Phyllograptus  and  Didymograptus, 
but  with  new,  younger  elements.  Four  of  the  seven  species  of  Tetragraptus 
of  the  preceding  zone  extend,  as  stated  before,  mostly  in  smaller  mutations 
into  this  zone,  and  two  other  species,  Tetragraptus  clarkii  and 
pendens,  appear  as  new  forms. 

Of  the  Phyllograpti,  P.  ilicifolius,  which  has  its  acme  in  the 
preceding  zone,  is  here  rare  and  disappears ;  P.  angustifolius  becomes 
more  common  than  before  and  continues  throughout  the  zone ;  P.  a  n  n  a , 
which  appeared  in  the  last  layer  of  the  preceding  zone,  is  here  one  of  the 
common  and  characteristic  fossils,  but  extends  also  into  the  lower  part  of  the 
next  zone.  P.  typus  appears  for  the  first  time  in  this  zone,  becomes 
extremely  common  and  probably  ends  with  it.  It  is,  hence,  apparent  that 
the  genus  Phyllograptus  culminates  in  this  zone. 

Of  the  Didymograpti,  the  horizontal  series  has  dwindled  down  to  one 
species,  D.  s  i  m  i  1  i  s.  The  declined  series  which  originated  in  the  preceding 
zone,  continues,  but  develops  very  little  strength  in  a  specific  and  individual 
representation.  The  dependent  series  is  entirely  restricted  to  this  zone  and 
furnishes  in  D.  bifidus  and  D.  nanus  most  characteristic  fossils  of 
the  same.  The  reclined  series  finally  begins  here  with  D.  caduceus 
( gib b  e  r  u  1  u  s). 

Of  the  multiramous  Dichograptidae,  Dichograptus  octobrach- 
i  a  t  u  s  endures  and  Goniograptus  disappears  after  developing  a  last,  interesting 
species  in  G.  geometricus.  No  more  species  of  Bryograptus  are  found. 
The  Dendroidea  are  faintly  represented,  among  them  the  genus  Ptilograptus 
with  two  species.  With  Sigmograptus  the  coenograptids  appear  on  the  scene. 

The  characteristic  members  of  this  fauna  are  the  Phyllograpti,  notably 
P.  typus  and  P.  anna,  the  dependent  or  “tuning  fork”  Didymograpti, 
D.  bifidus  and  D.  nanus;  and  a  horizontal  form,  D.  s  i  m  i  1  i  s. 

The  principal  species  were  originally  reported  by  Hall  from  a  place  “  3 
miles  above  the  River  St  Anne.”  Lapworth  recognized  this  association  in 
collections  from  the  same  locality  and  termed  it  the  St  Anne  zone  or  zone 


498 


NEW  YORK  STATE  MUSEUM 


with  Phyllograptus  anna.  Gurley  [1896]  records  the  occurrence  of 
D  idymograptus  b  i  f  i  d  u  s  and  Phyllograptus  anna  in  the 
graptolite  shale  of  Nevada. 

In  Great  Britain  Lapworth  records  a  similar  association  from  the  Ballan* 
trae  rocks  in  south  Scotland.  In  the  Skiddaw  slates  the  characteristic  species 
of  the  zone,  specially  Didymograptus  b i f i d u s,  Phyllograptus 
t  y  p  u  s  and  P  h  y  1 1  o  graptus  a  n  n  a,  are  found  in  the  upper  Tetragraptus 
subzone  which  overlies  the  Dicliograptus  zone.  In  Scania  the  zone  with 
Phyllograptus  cf.  t  y  p  u  s  and  Didymograptus  cf.  b  i  f  i  d  u  s  forms, 
according  to  Tullberg,  the  highest  part  of  the  lower  graptolite  shale  and 
overlies  the  Orthoceras  limestone.  But  as  this  is  also  reported  to  contain 
Climacograptus  and  Cryptograptus,  which  here  do  not  appear  till  the  next 
zone,  this  Scanian  and  the  Deep  kill  zone  can  not  be  exactly  parallelized ;  and 
it  is  to  be  assumed  that  the  typical  St  Anne  fauna  lies  a  little  deeper  and  is 
homotaxial  with  a  part  or  the  whole  of  the  Orthoceras  limestone  itself. 

In  Bohemia  Didymograptus  b  i  f  i  d  u  s  occurs  in  D  dir  [  Perner] ; 
and  in  France  its  occurrence  and  that  of  Rouvilligraptus  r  i  c  li  a  r  d- 
soni,  another  St  Anne  form,  indicate  the  presence  of  the  St  Anne  zone 
in  the  graptolite  shale  of  Cabrieres.  Finally,  T.  S.  Hall  [1893]  recognized 
the'  zone  of  Didymograptus  b  i  f  i  d  u  s  in  the  auriferous  shales  of 
Victoria,  Australia. 

It  is  hence,  with  our  present  evidence,  to  be  inferred  that  this  zone  in  all 
lower  graptolite  beds  of  the  world  is  directly. successive  to  and  also  coextensive 
with  the  preceding  Tetragraptus  zone. 

d  Zone  with  Diplograptus  dentatus  and  Climacograptus?  antennarius. 
This  zone  is  represented  at  the  Deep  kill  by  graptolite  beds  6  and  7,  which 
are  separated  by  an  interval  of  several  hundred  feet  of  nonexposure  from  the 
zone  with  Didymograptus  b  i  f  i  d  u  s.  The  writer’s  supposition  [1902] 
that  this  interruption  hides  a  transitional  zone,  of  similar  composition  as 
the  one,  just  mentioned,  in  Scania,  with  Didymograptus  bifid  us, 
Phyllograptus  typus,  intermingled  with  the  graptolites  of  the  zone 
of  Diplograptus  dentatus,  has  to  some  extent  been  verified  by  a 
fauna  found  at  Mt  Moreno  [see  note  below]. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


499 


This  third  Deep  kill  zone  is  characterized  by  the  suppression  of  the 
Dichograptidae  and  the  unheralded  appearance  of  the  axonophorous  Diplo- 
graptidae,  with  the  genera  Diplograptus,  Glossograptus,  Trigonograptus, 
Climacograptus  and  Retiograptus,  which  now  dominate  till  the  end  of  the 
Lower  Siluric.  Accordingly,  between  this  and  the  underlying  zone,  there 
has  taken  place  a  profound  change,  indeed  the  most  profound  change  to  be 
met  with  between  the  successive  graptolite  faunas ;  for  a  new  subclass,  the 
Axonophora,  built  on  an  entirely  new  plan,  have  taken  possession  of  the  field, 
and  the  Dichograptidae,  hitherto  holding  sway  in  the  wide  areas  occupied  by 
the  graptolites,  persist  only  in  a  few  stragglers. 

Note.  Transitional  subzone.  The  fortunate  discovery  of  a  Phyllograptus  in  the 
shales  of  the  Ashhill  quarry  at  Mt  Moreno  near  Hudson,  by  Prof.  A.  W.  Grabau,  has  led 
to  the  finding  there  of  a  fauna  which  is  a  blending  of  the  typical  forms  of  the  zone  with 
Diplograptus  dentatus  with  some  species  of  the  preceding  zone.  It,  therefore, 
appears  to  happily  fill,  to  a  great  extent,  the  gap  in  the  continuity  of  the  graptolite 
horizons,  caused  by  the  interruption  of  the  outcrops  between  graptolite  beds  5 
and  6  of  the  Deep  kill  section  (zones  with  Didymograptus  bifidus  acd 
Diplograptus  dentatus).1 

The  lithologic  character  of  the  beds  at  the  Ashhill  quarry  is  strikingly  similar  to  that 
of  the  Deep  kill  beds,  the  bands  of  black  graptolite  shales  being  also  intercalated  in 
thicker  masses  of  greenish,  silicious  shales.2 


The  Ashhill  quarry  has  furnished  the  following  forms  : 


Dendrograptus  sp .  r 

Ptilograptus  plumosus  Hall .  c 

Goniograptus  perflexilis  sp.  nov.  mut  . .  rr 
Tetragraptus  quadribrachiatus  Ilall ....  rr 

T.  taraxacum  sp.  nov .  .  rr 

T.  pygmaeus  sp.  nov .  r 

Didymograptus  forcipiformis  sp.  nov . .  c 

D.  filiformis  Tullberg .  r 

D.  gracilis  Tornquist .  r 


D.  cuspidatus  sp.  nov .  rr 

D.  spinosus  sp.  nov . .  r 

Phyllograptus  angustifolius  Ilall .  c 

Diplograptus  dentatus  Brong .  cc 

D.  laxus  sp.  nov . .  c 

Climacograptus  pungens  sp.  nov .  cc 

Glossograptus  hystrix  sp.  nov .  r 

Trigonograptus  ensiformis  Hall . . .  rr 

Retiograptus  tentaculatus  Hall .  r 


1  See  N.  Y.  State  Paleontol.  An.  Rep’t  1901,  pi.  2,  facing  p.  546. 

2  As  at  Mt  Moreno  these  Lower  Champlainic  graptolite  shales  are  exposed  in  close  proximity  to 
the  Normanskill  shales  of  Trenton  age,  this  locality  will  he  noticed  in  greater  detail  in  a  later 
publication  in  the  report  of  the  state  paleontologist. 


500 


NEW  YORK  STATE  MUSEUM 


While  the  typical  species  of  the  zone  with  Diplograptus  dentatus  prevail, 
both  in  number  of  species  and  individuals,  thus  characterizing  the  beds  as  belonging  to 
that  zone,  the  congeries  contains  still  a  goodly  number  of  species  met  only  in  the  deeper 
horizons  at  the  Deep  kill,  namely,  Goniograptus  perflexilis,  Tetragraptus 
taraxacum  and  T.  pygmaeus,  Didymograptus  filiformis  and  D.  gra¬ 
cilis.  The  Aslihill  quarry  beds  represent  hence  a  very  early  or  initial  phase  of  the  zone 
with  Diplograptus  dentatus  not  met  with  at  the  Deep  kill,  but  whose  existence 
was  surmised  on  account  of  the  considerable  break  in  the  rock  succession  at  that  place.1 
The  Den-droidea  which  constitute  so  large  a  portion  of  the  fauna  of  the  horizon  at  the 
Deep  kill  are  here  represented  only  by  a  species  of  Ptilograptus  and  a  few  fragments 
of  a  Dendrograptus ;  but,  as  they  also  fail  to  be  present  in  this  zone  in  other  countries, 
they  may  represent  but  a  local  element. 

A  notable  feature  of  this  faunule  is  the  considerable  number  of  species  not  observed 
elsewhere,  or  in  the  preceding  and  succeeding  horizons.  Some  of  these  forms,  as 
Didymograptus  cuspid  at  us  and  D.  spinosus,  represent  moreover  peculiar 
types  and  have  no  closely  related  congeners.  Other  species,  as  Diplograptus  laxus 
and  Climacograptus  p ungens,  which  are  new  and  very  rare  in  the  Deep  kill 
beds  with  Diplograptus  dentatus,  appear  here  in  great  profusion.  These  facts 
characterize  the  fauna  as  constituting  a  distinct  subzone  of  the  zone  with  Diplo¬ 
graptus  dentatus. 

e  Some  general  facts  of  distribution  of  graptolites  [see  chart].  The 
specific  identity  of  so  great  a  percentage  of  forms  in  faunas  characterizing 
successive  zones,  as  we  find  in  the  deeper  zones  of  the  Lower  Siluric,  over  so 
vast  an  area  as  that  outlined  above,  by  the  notes  on  the  distribution  of  the 
Lower  Siluric  graptolites,  is  a  fact  without  a  parallel  among  the  paleozoic 
faunas.  It  has  a  distinct  bearing  on  several  problems,  notably  on  that 
of  the  mode  of  existence  of  the  graptolites  and  of  the  distribution  of  land 
and  water  in  the  Lower  Siluric  time.  The  former  problem  will  be  discussed 
in  the  following  chapter,  the  relation  of  the  graptolites  to  paleography  however 
is  still  a  virgin  field,  promising  rich  fruit  after  a  most  detailed  comparison  of 
the  various  faunas.  We  can,  with  the  present  knowledge  of  the  distribution 
of  the  graptolites,  do  little  more  than  make  some  general  statements. 


1  See  N.  Y.  State  Paleontol.  An.  Rep’t  1901,  p.  572. 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


501 


It  has  been  pointed  out  by  Freeh  [1897,  2  : 88]  that  for  the  lower  and 
middle  Lower  Siluric  the  existence  of  four  grand  marine  provinces  can  be 
inferred,  which  were  more  or  less  separated  from  one  another.  These 
are  the  Bohemian-Mediterranean,  the  Baltic,  the  North  Atlantic,  and  the 
Pacific-North  American  basins.  The  former  existence  and  extension  of  these 
provinces  is  deduced  from  the  comparative  study  of  the  horizontal  distribu¬ 
tion  of  the  faunas,  specially  of  their  trilobite  element. 

The  graptolites,  however,  are  expressly  excepted  as  passing  beyond  the 
boundaries  of  these  basins.  Indeed,  we  find,  for  instance,  the  Tetragraptus 
zone  with  its  principal  forms  developed  in  the  northwestern  (St  Lawrence) 
and  northeastern  (British)  embayments  of  the  north  Atlantic  basin,  iu  the 
Baltic  basin  (Scancliuavia),  Bohemian-Mediterranean  basin  (southern  France) 
and  Pacific-American  basin  (province  of  Victoria,  Australia,  and  Nevada). 
The  same,  with  some  exceptions,  is  true  of  the  succeeding  zones,  at  least  as  far 
as  the  Trenton  or  Normanskill  fauna  is  concerned. 

This  phenomenon  is  explained  by  Freeh  by  their  pelagic  or  abysmal 
habitat  in  contrast  to  the  littoral  or  shallow  sea  habitat  of  the  provincial 
faunas,  which  consist  essentially  of  brachiopods,  mollusks  and  trilobites.  We 
shall  see  in  the  succeeding  chapter  that,  whatever  may  have  been  the  mode  of 
existence  of  the  graptolites,  for  various  reasons  they  can  not  be  considered  as 
having  been  littoral  benthonic  forms  living  in  association  with  the  representa¬ 
tives  of  the  other  classes  mentioned,  but  were  either  pelagic  or  abysmal 
organisms.  Either  of  the  latter  are,  today,  notable  for  the  vastness  of  the 
territory  inhabited  by  them,  many  of  the  former  and  nearly  all  of  the  latter 
being  cosmopolitan. 

While,  however,  the  most  common  and  characteristic  species  of  the 
graptolite  zones  appear  also  to  be  practically  cosmopolitan,  a  closer  comparison 
of  those  homotaxial  faunas  which  have  been  thoroughly  studied,  brings  to 
light  certain  differences  in  the  composition  of  the  faunas  which  may 
indicate  divisions  of  the  open  sea,  independent  of  those  suggested  by  the 
shallow  sea  organisms.  We  find  in  the  Upper  Cambric  Dictyonema 


502 


NEW  YORK  STATE  MUSEUM 


f  1  a  b  e  1 1  i  f  o  l*  m  e  zone,  that,  while  the  index  fossil  is  present  in  both 
America  and  North  Europe,  it  is  associated  in  Europe  with  a  species 
of  Clonograptus  (C.  t  e  n  e  1 1  u  s),  while  in  the  northwestern  embayment 
of  the  Cambric  Atlantic  sea,  Clonograptus  proximatus  Matthew 
(or  Staurograptus  dichotomus  Emmons)  appears  as  a  vicarious 
form  in  the  homotaxial  St  John  and  New  York  beds.  Elies  [1898,  463ff] 
concluded  in  regard  to  the  Skiddaw  slate  fauna,  that,  ‘‘though  it  is 
more  closely  related  to  the  fauna  of  the  Quebec  group  of  Canada  than 
to  that  of  any  English  beds,  it  is  still  more  nearly  related  to  the  Swedish 
fauna;  for,  while  of  the  whole  59  species,  25  are  common  to  the  Skiddaw 
slates  and  the  Quebec,  and  only  14  common  to  the  Skiddaw  slates  and  the  two 
other  English  areas,  no  less  than  34  species  are  common  to  the  beds  of  Sweden 
and  the  Skiddaw  slates.”  While,  with  further  elaboration,  undoubtedly 
still  more  forms  will  be  found  to  be  common  to  these  regions,  as  indeed  the 
writer’s  investigation  of  the  New  York  graptolites  distinctly  shows,  new  forms 
are  being  discovered  which  are  not  known  to  the  other  territories,  and  thus 
the  differences  in  the  composition  of  the  equivalent  faunas  will  be  maintained. 
These  differences  are  probably  of  a  provincial  or  regional  nature,  as  the  closer 
approximation  of  the  regionally  adjoining  Swedish  and  Skiddaw  faunas 
indicates. 

A  still  wider  difference  appears  to  exist  between  the  Lower  Siluric 
graptolite  faunas  of  Bohemia  and  northern  Europe,  which  have  but  very 
few  species  in  common.  This  coincides  with  the  great  difference  of  the 
littoral  faunas  of  the  Bohemian  and  Scandinavian  Lower  Siluric  seas,  belonging 
respectively  to  the  Bohemian  and  Baltic  basins.  On  the  other  hand,  the 
graptolite  fauna  of  Cabrieres  in  southern  France,  which  also  belongs  to  the 
Bohemian-Mediterranean  basin,  contains  a  greater  number  of  the  more 
important  forms  of  the  Scandinavian  or  Skiddaw  faunas.  [See  appended  chart 
on  the  distribution  of  the  Lower  Siluric  graptolite  faunas] 

Some  facts  concerning  the  distribution  of  the  Lower  Siluric  graptolites 
are  entirely  at  variance  with  the  distribution  of  the  land  and  water  masses, 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


503 


as  it  can  be  reconstructed  for  the  Lower  Siluric  age  from  the  study  of  the 
littoral  faunas.1  One  of  these  is  the  appearance  of  the  peculiar  generic  type 
Goniograptus  with  the  same  species,  G.  thureaui,  in  Victoria,  Australia, 
in  the  south  Australian  sea  of  that  age  which  formed  presumably  a  south¬ 
western  embayment  of  the  Pacific-American  basin,  and  in  the  homotaxial 
Tetragraptus  beds  of  Point  Levis,  Canada,  and  the  Deep  kill,  New  York, 
while  no  trace  of  it  has  been  found  in  the  corresponding  European  beds. 
The  only  explanation  of  this  abnormal  distribution  can,  in  the  writer’s 
opinion,  be  found  in  the  assumption  that  the  supposed  “  Levis  channel  ”  of 
Ulrich  and  Schuchert  had  at  that  time  not  only  an  open  connection  with  the 
northwestern  (St  Lawrence)  embayment  of  the  North  Atlantic  basin,  but  also 
at  its  southern  terminus  with  the  Pacific-American  basin,  and  that  oceanic 
currents  connected  the  habitats  of  Goniograptus  thureaui,  at 
present  antipodal  regions.  [ See  chart] 

Another  irregularity  of  distribution  can  be  found  in  the  appearance  of 
the  Dendroidea,  with  the  genera  Dendrograptus,  Dictyonema,  Callograptus 
and  Ptilograptus,  in  great  force  at  certain  localities,  while  they  are  absent 
in  homotaxial  beds  at  others.  Thus  Lap  worth  and  Hopkinson  [1875,  p.635] 
enumerate  from  the  graptolite  beds  on  Ramsey  island,  Wales,  10  Dendroidea 
to  only  six  Graptoloidea.  From  the  whole  St  Davids  district  they  record 
15  Dendroidea  to  20  Graptoloidea,  while  the  Dendroidea  are  entirely  absent 
in  the  corresponding  beds  of  the  English  Lake  district,  and  are  rare  in 
the  homotaxial  beds  of  the  Quebec  region.  They  are,  further,  extremely 
prominent  in  species  and  individuals  in  the  third  Deep  kill  zone,  that  of 
Diplograptus  den  tat  us  [see  table  of  distribution  of  species,  p.504], 
while  they  are  absent  in  the  same  zone  at  Point  Levis  and  in  the  Lake  district; 
and  are  hardly  represented  at  Mt  Moreno.  The  peculiarly  local  distribution  of 
this  class  of  graptolites  would  seem  to  suggest  a  mode  of  existence  different 
from  that  of  the  other  members  of  the  group  [p.514]. 


1  See  Freeh.  Lethaea  palaeozoica,  v.l,  chart  2. 


504 


NEW  YORK  STATE  MUSEUM 


SYNOPTIC  TABLE  OF  THE  DISTRIBUTION  OF  THE  CAMBRIC 

(i'r- rare ;  rr= Very  rare;  c  =  common; 


M 

u 

O 

Deep  Kill 

M 

u 

o 

o 

A 

<H 

O 

*d 

a> 

P 

a 

a 

o 

O 

0) 

a 

o 

S3 

Tetragraptus 

o> 

d'U 

fl¬ 

ee 

S3^ 

CO 

‘1 

Zone  of 

Dipl. 

dentatus 

ocalities  in  New 

and  Vermont 

o 

1 

o 

5 

*d 

0) 

ffl 

0) 

pq 

2 

PQ 

'd 

o 

dJ 

<D 

'd 

<D 

pq 

a 

o 

1 

Dictyonema  flabelliforme  Eichwald . 

cc 

2 

T)  rfict.il  in  pa  turn  R  uedem.ann . 

r 

3 

D.  f urciferum  Ruedemann . 

r 

r 

4 

D  murrayi  Hall . 

17 

5 

Desmograptus  eaneellatus  Hopkinson . 

c 

6 

D.  intricatus  Ruedemann . 

c 

7 

Dendroeraptus  flexuosus  Ilall . 

c 

r 

8 

D.  fluitans  Ruedemann  . . 

r 

9 

D.  succulentus  Ruedemann . 

c 

10 

Callograptus  salteri  Hall . 

r 

c 

r 

11 

C.  cf.  diffnsns  Hall . 

r 

r 

12 

Ptiloeraotus  plmnosus  Hall .  . . 

rr 

(c)18 

13 

O  1  X" 

P.  geinitzianus  Ilall . 

rr 

14 

P.  tenuissimus  Ilall . 

rr 

15 

Bryooraptus  lapworthi  Ruedemann . 

c 

cc 

16 

B.  pusillus  Ruedemann . 

rr 

17 

Staurograptus  dickotomus  Emmons . 

cc 

5 

18 

Clonograptus  ef.  flexilis  Ilall . 

17 

19 

Goniograptus  thureaui  McCoy . 

CC 

c 

20 

G.  eeometricus  Ruedemann . . 

r 

cc 

21 

o 

G.  perflexilis  Ruedemann . 

cc 

r 

22 

Loeanosraptus  loa:ani  Hall . .  . . 

rr 

rr 

23 

Dichograptus  octobrachiatus  Ilall . . . 

rr 

cc 

r 

24 

Tetragraptus  qnadribrackiatus  Hall . 

cc 

r 

rr 

(rr)  i7,  is 

25 

T.  amii  Elies  &  Wood . 

c 

26 

T.  fruticosus  Ilall . . . 

c 

cc 

cc 

27 

T.  clarkii  Ruedemann . 

c 

28 

T.  pendens  Elies . 

r 

29 

T.  serra  Rrongniart . 

r 

c 

17 

30 

T.  sirailis  Hall . 

cc 

c 

31 

T.  taraxacum  Ruedemann.  ...  . 

r 

(r)18 

(rV8 

32 

T.  pvsrmaeus  Ruedemann  . 

c 

r 

33 

T.  lentus  Ruedemann .  . 

r 

V  J 

34 

Didymoeraptus  extensus  Ilall . 

cc 

35 

D.  nitidus  11 all . 

c 

c 

36 

D.  patulus  Hall .  . 

cc 

cc 

1Cape  Breton  island;  Cape  Rosier,  Gaspe.  2  Also  in  Ostrogothia,  Vestrogothia  and  Esthonia, 
Russia;  Bornholm  and  Ireland.  3Gros  Maule,  Canada.  4 Orleans  island  [Ami],  5 Rensselaer 
county,  N.  Y.  [Emmons].  6 Cape  Rosier  zone,  Canada  [Lapworth],  8  Also  Orthoceras  limestone  of 
Oeland.  9  Also  Vestrogothia.  10  Also  in  South  Shropshire  (Shelve  district).  11  Kiltrea  near  Ennis- 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


505 


AND  LOWER  CHAMPLAINIC  GRAPTOLITES  OF  NEW  YORK 

cc  -  very  common ;  x  =  present) 


Levis,  Quebec 

Miscellaneous 

Sc  John 
Division  3 

Newfoundland 

Arkansas  (A)  or  Nevada  (N) 

Arenig,  South  Scotland 

Arenig 
Lake  district 
North  England 

Upper  Lingula  flags,  Wales 

Arenig,  St  Davids  etc.,  Wales 

Christi¬ 

ania 

Scania 

Dalarne 

Belgium 

Bohemia 

France  (Cabriferes) 

Australia 

Main  Point  Levis 
zone 

Phyllograptus 
anna  zone 

Point  Levis  zone 

b&c 

d 

Lower  Skiddaw 

Middle  Skiddaw 

U pper  Skiddaw 

2d 

Phyllograptus  co 

shale  & 

1 

X 

X 

X 

X3 

X 

X 

X 

X 

X 

3 

X 

X 

X 

X 

4 

X 

X 

6 

X 

X 

X 

X 

4 

X 

X 

X 

X 

X 

X 

.  .  . 

X 

'l 

X 

X 

X 

X 

X 

X 

.  .  . 

X 

X 

.  .  . 

X 

X 

X 

.  . 

.  . 

X 

X 

X 

X 

X 

X 

X 

4 

X 

•  •  • 

X 

X 

X 

X 

X 

X 

X 

X 

X 

3 

X 

A 

X 

.  .  . 

X 

X 

.  .  . 

X 

X 

X9 

.  • 

.  . 

X 

X 

X 

X 

X 

X 

X 

X 

X8 

X 

•  *  * 

X 

X 

X 

X 

X 

X 

X 

X9 

X 

?x 

X 

X 

X10 

.  .  • 

?  X 

X 

X 

X 

X 

* 

worthy,  Ireland.  12  Also  New  Zealand.  13  Also  in  Ireland.  14  In  uppermost  layers.  15Chaudiere 
river,  Canada.  16  Top  of  Phyllograptus  zone.  17  Sandy  shale  between  Defreestville  and  West  Sand- 
lake,  N.  Y.  18  Mt  Moreno  near  Hudson  N.  Y.  (lower  part  of  zone  of  Dipl,  dentatus) 


506 


NEW  YORK  STATE  MUSEUM 


SYNOPTIC  TABLE  OF  THE  DISTRIBUTION  OF  THE  CAMBRIC 

(r  =  rare ;  rr  =  very  rare ;  c  =  common ; 


M 

u 

O 

h 

Deep  Kill 

M 

u 

o 

h 

£ 

© 

£ 

o 

'C 

© 

-O 

a 

B 

© 

CO 

d 

°Sj 
©  u 
a  bp 

O  03 

© 

■M 

° 

So- 
N  * 

CO 

© 

°n  £ 
Nw  0 

* 

©-M 

Si 

s® 

g§ 

o 

o 

5 

r— 1 

'O 

© 

« 

'M 

'd 

© 

« 

CO 

© 

« 

to 

© 

CO 

'd 

© 

« 

fc- 

'd 

© 

n 

u 

© 

i£l 

O 

37  D.  similis  Hall . 

r 

c 

38  D.  acutidens  Lapworth . . . 

rr 

39  Didymograptus  cuspidatus  Ruedemann . 

(rr)18 

(r)18 

40  D.  gracilis  Tornquist . . 

c 

41  D.  ellesi  Iiuedemann . 

c 

42  D.  nicholsoni  var.  planus  Elies  <&  Wood . 

r 

43  D.  tornquisti  Iiuedemann . 

r 

44  D.  filiformis  Tull.herg  ...  . 

r 

45  D.  bifid  us  Ilall . 

cc 

CC 

46  D.  nanus  Lapworth . 

X 

47  D.  caduceus  Salter .  ...  . 

c 

48  D.  caduceus  Salter ,  mut.  nana . 

c 

49  D.  forcipiforrois  Iiuedemann . 

(c)18 

50  D.  incertus  Iiuedemann  . 

rr 

51  D.  spinosus  Iiuedemann . 

(r)18 

52  Phyllograptus  typus  Hall . 

c 

cc 

53  P.  ilicifolius  Hall . 

r 

cc 

r 

54  P.  ancmstifoliiis  Hall . 

rr 

r 

0, 

c 

(c)18 

55  P.  anna  Hall . 

r14 

cc 

c 

c 

56  Temnograptus  noveboracensis  Iiuedemann . 

c 

57  Sigmagraptus  praecursor  Iiuedemann . 

rr 

58  Strophograptus  trichomanes  Iiuedemann . 

c 

59  Diplograptus  dentatus  Brongniart . 

r 

cc 

(cc)18 

60  D.  inutilis  Hall . 

r 

61  D.  longicaudatus  R uedemann .  , . 

rr 

62  D.  laxus  Ruedemann . . . 

c 

(c)18 

(r)18 

63  Glossograptus  liystrix  Ruedemann . 

r 

64  G.  echinatus  Ruedemann . 

rr 

65  Trigonograptus  ensiformis  Hall . 

r 

cc 

(r)18 

(c)18 

(cc)18 

(r/8 

66  Climacograptus  ?  antennarius  Hall . 

cc 

67  G.  pungens  Ruedemann . 

r 

68  Ketiograptus  tentaculatus  Hall . 

c 

r 

69  Pawsonia  monodon  Gurley . 

c 

c 

70  D.  tridens  Gurley . 

c 

71  Caryocaris  curvilineatus  Gurley . 

c 

1Cape  Breton  island;  Cape  Rosier,  Gaspe.  2  Also  in  Ostrogothia,  Vestrogotliia  and  Esthonia, 
Russia;  Bornholm  and  Ireland.  3 Gros  Maule,  Canada.  4 Orleans  island  [Ami].  5 Rensselaer 
county,  N.  Y.  [Emmons].  6 Cape  Rosier  zone,  Canada  [Lapworth],  8  Also  Orthoceras  limestone  of 
Oeland.  9  Also  Vestrogothia.  10  Also  in  South  Shropshire  (Shelve  district).  11  Kiltrea  near  Ennis- 


GRAPTOLITES  OF  NEW 


YORK,  PART  1 


507 


AND  LOWER  CHAMPLAINIC  GRAPTOLITES  OF  NEW  YORK  ( concluded ) 
cc  =  very  common ;  x  present) 


Levis,  Quebec 

Miscellaneous 

II 

St  John 
Division  3 

Newfoundland 

Arkansas  (A)  or  Nevada  (N) 

Arenig,  South  Scotland 

Arenig 
Lake  district 
North  England 

Upper  Lingula  flags,  Wales 

Arenig,  St  Davids  etc.,  Wales  1 

Christi¬ 

ania 

Scania 

Dalarne 

Belgium 

Bohemia 

France  (Cabrieres) 

Australia 

« 

o 

■£  © 

*3 

Cfi 

fg 

c3  O 
a 

Point  Levis  zone 

b&c 

d 

Lower  Skiddaw 

Middle  Skiddaw 

tipper  Skiddaw 

2d 

Phyllograptus  co 

shale  & 

X 

.  .  . 

xio,  n 

X 

?X9 

X10 

X 

X 

X 

.... 

X 

X 

X 

% 

.... 

X 

X 

1ST 

X 

.  .  . 

X 

X 

.  .  . 

x10,  13 

X 

X 

X 

X 

,  . 

.... 

X 

X 

.  .  . 

X 

X 

X 

X 

X9 

... 

x12 

X 

X 

?  A 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

Xs 

X 

.  .  . 

15 

A,N 

X 

X 

A 

... 

X 

X10 

X16 

X 

X 

A 

X 

X 

X 

A 

X 

'  1 

...  * 

... 

X 

?  X 

" 

. .. 

X 

X 

. .. 

X 

worthy,  Ireland.  12  Also  New  Zealand.  13  Also  in  Ireland.  uIn  uppermost  layers.  15Cliaudiere 
river,  Canada.  16  Top  of  Phyllograptus  zone.  17  Sandy  shale  between  Defreestville  and  West  Sand- 
lake,  N.  Y.  18 Mt  Moreno  near  Hudson  N.  Y.  (lower  part  of  zone  of  Dipl,  dentatus). 


Axonophora  Graptoloidea  Axonolipa  Dendroidea 


508 


NEW  YORK  STATE  MUSEUM 


SYNOPTIC  TAHLE  OF  THE  RANGE  OF  THE  GENERA  OF  THE  CAMBRIC  AND  LOWER  CHAMPLAINIC 

OF  NEW  YORK 


o 


Dictyonema 
Desmograptus 
“  Dendrograptus 
Callograptus 
„  Ptilograptus 
Bryograptus 
Staurograptus 
Temnograptus 
Goniograptus 
Logan  ograptus 
Dicli  ograptus 
Tetragraptus 
Pliyllograptus 
Didymograptus 

a)  horizontal  series 

b)  declined  series 

c)  dependent  series 

d)  reclined  series 
Sigmagraptus 

,  Strophograptus 
Diplograptus 
Glossograptus 
■j  Trigonograptus 
Climacograptus 
Retiograptus 
Dawsonia 
Caryocaris 


Zone  of  Zone  of 

Zone  of  Zone  of  Tet.  Did.  bifidus  Dipl,  dentatus 

Diet.  , - * - « - ‘ - - - * - n 

f labelli-  Bed  1  Bed  2  Bed  3  Bed  5  Mt  Beds6-7 
forme  Deep  Kill  Deep  Kill  Deep  Kill  Deep  Kill  Moreno  Deep  Kill 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


509 


6  Mode  of  existence 

The  problem  of  the  mode  of  existence  of  the  graptolites  has  as  a  rule 
been  touched  but  incidentally  by  investigators,  and  the  views  entertained 
by  various  authors  regarding  its  solution  differ  widely.  Moreover,  as  with 
but  few  exceptions,  only  fragments  of  the  rhabdosomes  are  known,  and  these 
were  taken  for  the  whole  colonies,  these  views  are  mostly  based  on  erroneous 
conceptions  of  the  rhabdosomes. 

Hall  [Quebec  Grapt.  p.38,39],  though  using  the  term  “ radicle”  for  the 
sicula,  considered  the  Graptoloiclea  free  floating  organisms,  as  appears  from 
the  following  statement :  “  For  all  those  species  with  a  single  range  of  cellules, 
as  well  as  for  some  with  a  double  range,  including  Retiolites,  Retiograptus, 
and  Phyllograptus,  I  conceive  that  we  have  already  shown  a  similar  plan  of 
development  and  a  uniform  mode  of  existence ;  and  we  are  constrained  to 
believe  that  all  these  forms,  in  their  mature  condition,  were  free  floating 
bodies  in  the  Silurian  seas.”  In  regard  to  the  Dendroidea  he  “  inferred  their 
attachment  either  to  the  sea  bottom  or  to  foreign  bodies,”  but  adds  that 
he  has  never  observed  them  attached,  largely  because  there  do  not  occur  in 
the  graptolite  beds  any  other  bodies  to  which  they  could  be  attached ;  but 
neither  has  any  evidence  been  found  of  the  attachment  of  the  Dictyonemas 
which  in  the  Niagara,  Upper  Helderberg  and  Hamilton  groups  occur  in 
association  with  large  numbers  of  other  fossils.  Richter,  Scharenberg  and 
Geinitz  expressed  the  opinion  that  the  graptolites  were  attached  by  their 
Fuss  (sicula),  or  had  this  lower  extremity  plunged  into  the  mud  or  sand 
[Geinitz].  Nicholson  held  that  some  (as  Didymograptus)  were  attached,  and 
others  (as  Monograptus  and  Coenograptus)  were  free.  Herrmann  assumes 
“  that  all  graptolites  provided  with  a  sicula  were  not  attached  bodies,”  basing 
his  view  on  the  tapering  of  the  sicula  into  a  fine  point  or  nema  or  its  supposed 
disappearance.  He  leaves  the  question  open,  whether  they  were  inserted  into 
the  mud  with  this  free  end  or  kept  at  small  depths  “  like  a  Cartesian  diver,” 
while,  like  all  other  graptologists,  he  considers  the  arborescent  forms  (Den¬ 
droidea)  as  having  been  attached. 


510 


NEW  YORK  STATE  MUSEUM 


Jaekel  sketched  the  mode  of  existence  of  the  graptolites  very  decidedly 
in  1889,  asserting  that  they  formed  meadows  at  the  sea  bottom  and  fixed 
themselves  with  a  network  of  root  fibers.  His  arguments  for  this  conception 
were,  that  the  graptolites  can  not  have  been  free-swimming  for  the  reason 
that  their  colonies  were  too  heavy  to  be  earned  by  the  water;  that  they 
would  have  had  either  to  move  by  concerted  movements  of  the  zooids,  against 
which  the  independence  of  the  thecae  and  of  their  apertures,  and  the  form  of 
the  rhabdosomes  militate,  or  that  they  would  have  had  to  use  a  hydrostatic 
apparatus.  In  the  latter  case,  the  central  disk  would  have  to  be  regarded  as 
that  organ  ;  it  would  then,  however,  have  been  floating  above  the  colony  and 
the  thecae  would  have  been  directed  downward,  which  is  considered  as 
unnatural. 

The  same  conception  of  the  mode  of  existence  of  the  graptolites  was 
attained  by  Wiman  [1895,  p.68]  by  the  following  considerations.  The 
graptolite  beds  can  not  have  been  deposited  in  the  shallow  littoral  regions 
on  account  of  their  thin  bedding,  they  can  not  be  supposed  to  be  deep  sea 
deposits,  and  are  hence,  by  exclusion,  deeper  littoral  deposits.  The  grapto- 
iites  were  however  not  pelagic,  as  the  occurrence  in  these  beds  of  deeper 
origin  might  suggest,  for  then  they  would  occur  as  frequently  in  limestones 
as  in  shales ;  further,  on  account  of  the  great  similarity  of  their  external  form, 
they  all  must  have  had  the  same  mode  of  existence  and  belonged  to  the  same 
fauna,  but  the  combined  length  and  stiffness  of  the  nemacaulus,  which  is  still 
increased  by  the  virgula,  as  well  as  the  adhering  disk  of  some  forms,  point  to 
an  upright  position  of  the  rhabdosome. 

The  present  writer  discovered  in  the  Utica  shale  complete  synrhabdo- 
somes  of  Diplograptus  and,  observing  a  central  bulb,  or  cystlike  organ, 
described  this  as  having  probably  had  the  function  of  a  “float”  [1894, p.225], 
basing  his  assertion  of  the  floating  habit  of  this  genus  of  graptolites  on  the 
great  length  and  thinness  of  the  nemacaulus  supporting  the  rhabdosome, 
the  absence  of  attached  specimens  among  the  numerous  synrhabdosomes 
observed,  and  the  facts  of  the  distribution  of  the  graptolites. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


511 


Giirich  [1896,  p.960]  had,  at  the  same  time,  by  his  study  of  the  Polish 
graptolite  horizons  arrived  at  the  conclusion  that  the  monograptids,  populating 
these  horizons,  had  belonged  to  the  plankton.  He  cites  as  his  arguments  the 
geologic  distribution  of  the  graptolites,  their  mode  of  preservation  in  the  rock, 
their  appearance  in  lieteropic  beds  and  their  accumulation  in  such  beds,  which 
for  other  reasons  also  must  be  considered  as  formations  of  the  deeper  sea.  He 
finds  a  verification  of  his  views  in  the  writer’s  observations  on  Diplograptus. 

The  former  mode  of  existence  of  fossil  marine  animals  has  been 
thoroughly  studied  by  Johannes  Walther  [1897].  The  graptolites  have 
thereby  excited  his  special  interest,  because,  as  a  group  of  most  excellent 
index  fossils,  they  must  have  lived  under  conditions  greatly  different  from 
those  indicated  by  the  mode  of  occurrence  of  the  majority  of  fossils.  He  finds 
that  they  were  most  pronounced  facies  animals,  being  bound  to  thinly  bedded, 
carbonaceous  shales.  The  connection  of  the  graptolites  with  a  distinct  facies, 
it  is  stated,  would  argue  for  the  conclusion  that  the  graptolites  belonged  to 
the  sessile  benthos,  being  attached  in  some  fashion  to  the  bottom  of  the  sea, 
as  has  been  claimed  by  Jaekel.  The  author  rejects  this  conclusion  on  the 
ground  that  in  that  case  they  should  occasionally  be  found  to  pass  the  bed¬ 
ding  planes,  while,  as  he  was  informed  by  Professor  Lindstrom,  they  are  never 
found  in  that  position  in  the  Swedish  graptolite  shales,  the  sandstones  or 
limestones.  The  clue  to  the  solution  of  the  apparent  contradiction  of  the 
occurrence  of  the  graptolites  in  a  characteristic  facies  and  on  the  bedding 
planes  was,  as  he  states,  furnished  to  him  by  Professor  Lapworth,  who  prepared 
a  statement  of  his  views,  published  in  the  same  paper. 

We  can  not  refrain  from  enumerating  here  the  important  conclusions  of 
this  authority  on  matters  referring  to  graptolites. 

Lapworth  found,  during  his  extended  researches  of  the  English  grapto- 
litiferous  beds,  that  the  -typical  or  rhabdophorous  graptolites  occur  in  all  sedi¬ 
ments,  but  are  most  frequent  in  such  deposits  as  possess  a  strong  admixture  of 
carbonaceous  matter,  and  that  the  number  of  genera,  species  and  individuals 
increases  in  direct  proportion  (1)  to  the  quantity  of  carbonaceous  matter, 


512 


NEW  YORK  STATE  MUSEUM 


(2)  to  the  fineness  of  the  sediment,  and  (3)  to  the  length  of  the  time  of  deposi¬ 
tion.  He  concludes,  further,  that  the  graptolites  did  not  produce  the  car¬ 
bonaceous  matter  of  the  black  shales  by  their  decomposition,  for  they  are 
never  found  as  partly  decayed  rhabdosomes,  which  pass  into  the  surrounding 
carbonaceous  matter.  That  they  did  not  live  as  sessile  benthos  attached  to 
the  bottom  of  the  sea  can  be  inferred  from  the  fact  that  they  never  pass 
vertically  from  one  bed  to  the  other,  but  are  always  spread  out  as  if  they  had 
slowly  settled  in  tranquil  water. 

The  distribution  of  the  typical  black  graptolite  shales  of  Great  Britain 
shows  further  that  they  preserve  their  strikingly  thin  bedding  and  finegrained 
character  over  enormous  distances  in  a  northeasterly  and  southwesterly  strike, 
but  that,  when  traced  in  the  direction  from  northwest  to  southeast,  they 
rapidly  change  into  coarser  sediments  and  graywackes,  or  into  deposits  of 
shallow  water  with  surface  currents.  This  northeast-southwest  extension  is 
now,  for  certain  reasons,  to  be  considered  as  running  parallel  to  the  protozoic 
coast  line,  and  the  graptolite  beds  in  England  are  hence  dependent,  in  a  sense, 
on  the  old  coast  lines  of  that  period.  While  the  absence  of  clastic  material  in 
the  Moffat  shales  proves  their  deposition  in  deep  water  distant  from  the  coast, 
the  black  graptolite  shales  embedded  in  the  contemporaneous  coarser  sedi¬ 
ments  of  Girvan  and  Wales  were  deposited  at  a  much  faster  rate.  Hence  the 
same  black,  fine,  muddy  sediments  can  be  formed  in  deeper  and  shallower 
water,  and  not  the  depth  but  the  tranquillity  of  the  water  is  the  most 
essential  factor. 

As  the  graptolites  did  not  furnish  the  cellulose  material  for  the  car¬ 
bonaceous  shales,  it  is  to  be  inferred  that  this  was  derived  from  plants.  On 
account  of  the  scarcity  of  land  plants  in  the  lowest  Ordovicic,  there  remains,  by 
exclusion,  the  derivation  of  the  carbonaceous  matter  from  drifting  seaweeds. 
The  enormous  masses  of  Sargassum  which,  torn  from  the  coasts,  continue  to 
live  while  drifting  in  the  oceans  as  pseudoplankton,  are  cited  as  a  recent 
example  for  comparison. 

The  bands  of  carbonaceous  beds  would  then,  according  to  Lapworth, 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


513 


represent  a  zone  between  the  agitated  bottom  where  coarser  sediments  are 
deposited  and  the  dead  water  of  the  deep  sea. 

Lapworth  infers  further,  from  the  writer’s  observations  on  Diplograptus 
and  other  facts,  that  the  nema  of  every  sicula  was  originally  an  organ  of  attach¬ 
ment,  either  to  a  “  central  organ  ”  or  to  a  foreign  body.  He  has  found,  that  in 
the  Dendroidea,  to  which  also  Dictyonema  belongs,  all  transitions  occur 
from  the  stem  of  the  typical  Dendroidea  to  the  threadlike  nema.  In  the  lat¬ 
ter  case  they  must  have  been  suspended  like  a  bell  at  the  end  of  a  rope  from 
the  supporting  object.  They  were  now,  according  to  Lapworth,  attached  to 
floating  objects,  as  seaweeds ;  and  this  is  held  to  explain  both  their  constant 
appearance  in  carbonaceous  sediments  and  their  world- wide  distribution.  In 
support  of  this  hypothesis  are  further  cited  the  facts  that  only  the  siculate  and 
funiculate  graptolites  swarmed  in  such  multitudes  over  the  world,  while  the 
sessile  Dendroidea  are  by  no  means  common ;  that  further  the  first  profuse 
appearance  of  graptolites,  in  the  upper  Cambric  Dictyonema  fauna,  is  that  of 
siculate  suspended  forms.  These,  Lapworth  argues,  are  the  first  types  in 
which  the  originally  beuthonic  mode  of  existence  has  changed  into  a  pseudo- 
planktonic  ;  and  it  is  suggested  that  they  thus  escaped  from  some  creeping 
enemy. 

With  this  change  in  the  mode  of  existence  was  connected  the  complete 
reversion  in  the  position  of  the  whole  rhabdosome  which  gradually  took  place 
during  the  development  of  the  various  graptolite  series.1  Its  purpose  was  to 
restore  to  the  thecae  their  original  ascending  direction. 

The  distinguished  author  concludes  by  stating  that  it  can  be  considered 
as  established,  that  some  graptolites,  specially  the  Dendroidea,  were  attached 
during  their  lifetime  to  fixed  objects,  that  possibly  others  belonged  to  the 
plankton  proper,  but  that  the  majority  of  the  typical  graptolites  lived  as 
pseudoplankton. 

’This  interesting  and  significant  reversion  is  fully  described  in  the  chapter  on  the 
phylogeny  of  the  graptolites  [see  p.530]. 


514 


NEW  YORK  STATE  MUSEUM 


Frecli  [Lethaea  palaeozoica,  1:684]  considers  the  graptolites  as  gre¬ 
garious,  free  planktonic  organisms.  His  conception  is  based  on  the  present 
writer’s  observations  on  Diplograptus,  while  Lapworth’s  views,  just  cited,  had 
not  been  published  and  have  therefore  not  been  taken  into  consideration.  Of 
special  interest  is  Freeh’s  discussion  of  certain  hitherto  problematic  features 
of  the  graptolite  structure  in  the  light  of  a  possible  planktonic  existence 
[ibid,  p.552].  The  semicircular  expansions  of  the  distal  ends  of  the  rhabdo- 
somes  of  Diplograptus  phy  sophora,  formerly  described  by  Lap- 
worth  as  air  cells,  the  distal  “discus”  of  Monograptus  pal  a  and  the 
well  known  distal  expansions  between  strong  spines  of  Climacograptus 
bicornis  are  considered  as  steering  rudders  used  in  the  rising  and  sinking 
of  the  synrhabdosomes.  The  rudderlike  broadening  of  the  entire  stipe 
of  the  later  Diplograptidae  (Cephalograptus)  and  the  alate  pellicle  of 
Dicellograptus  divaricatus  var.  rigida1  are  also  held  to  have 
subserved  the  same  function.  The  solid  axis  of  the  rhabdosomes,  in  which 
'Wiinan  saw  an  argument  against  their  possible  suspension,  is  explained  as 
having  served  to  strengthen  the  rudder  pole. 

In  undertaking  to  present  our  own  views  on  this  important  problem  of  the 
mode  of  existence  of  the  graptolites,  we  will  state  at  the  outset  that  our 
observations  agree  fully  with  the  facts  brought  forward  by  Lapworth,  and 
that  we  believe  his  hypothesis  furnishes  a  very  plausible  explanation  for 
numerous  characters  of  at  least  one  large  group  of  graptolites.  It  appears 
further  that,  in  the  discussion  of  the  problem  before  us,  the  three  principal 
groups  of  this  class,  which  succeed  each  other  in  time  of  appearance, 
namely  the  Dendroidea,  the  Axonolipa  or  the  Graptoloidea  without  solid 
axes  and  the  Axonophora  or  forms  with  axes  [p.546],  should  be  treated 
separately. 

The  Dendroidea  approach  in  their  habit  most  closely  to  certain  recent 
Hydrozoa ;  they  have  been  observed  to  possess  sometimes  a  distinct  network 

‘The  New  York  State  Museum  contains  specimens  belonging  to  this  genus  in  which 
a  continuous  pellicle  is  stretched  between  the  entire  distal  part  of  the  two  branches. 


GRAPTOLITES  OF  NEW  YORK,  TART  1 


515 


of  liydrorhiza  or  adhesive  threads  such  as  the  mature  hydroids  have.  They 
were  hence,  at  least  in  these  cases,  firmly  attached  in  an  upright  position  to  the 
sea  bottom  or  to  other  bodies,  probably  sessile  seaweeds.  Hence  their  localized 
appearance.  Other  Dendroidea,  as  Dictyonema  flabelliforme, 
have  no  doubt,  at  least  at  certain  stages,  been  suspended,  as  the  relation  of 
their  long  thin  nema  to  the  large  rhabdosome  distinctly  demonstrates  [pi.  11 
We,  hence,  agree  with  Lapworth  that  the  Dendroidea  may  have  been  partly 
attached  in  an  upright  position  to  the  sea  bottom  or  seaweeds  and  partly  have 
been  suspended  from  seaweeds.  Whether  any  were  free  floating  can  not  now 
be  established  ;  but  the  discovery  among  the  hydroids  of  free  floating  colonies 
or  hydroid  colonies  actually  moving  independentl}’,  by  the  concerted  action  of 
the  zooids,  which  do  not  differ  from  the  sessile  ones,  proves  that  an  analogous 
case  among  the  Dendroidea  [see  Dictyonema  flabelliforme,  p.595] 
may  be  possible. 

As  to  the  rhabdosomes  of  the  Graptoloidea  or  graptolites  proper,  Lap- 
worth,  Giirich,  Freeh  and  the  present  writer  in  former  publications  agree  that 
they  were  suspended.  Jaekel’s  argument,  which  he  brought  forward  for  a 
sessile  mode  of  life,  namely  that  the  thecae  would  naturally  be  turned  upward 
toward  the  food  supply,  can  be  directly  used  as  an  argument  for  the  opposite 
hypothesis,  as  the  investigations  of  Wiman  and  the  present  writer  have  since 
shown,  that  in  the  axonophorous  graptolites  the  first  theca  reverses  its  original 
direction,  and  the  succeeding  thecae  grow  backward  along  the  nemacaulus 
to  attain  this  ascendant  position.  In  regard  to  the  Axonolipa  (Dichograp- 
tidae)  Lapworth  has  pointed  out,  that,  on  the  whole,  branches  change 
their  dependent  position  gradually  into  a  reclined  or  recumbent  position  to 
attain  the  same  result. 

There  remains  then  to  be  discussed  only  the  question  whether  all  the 
graptolites  proper  or  Graptoloidea  were  suspended  from  seaweeds  or 
all  from  a  “float”  of  their  own,  or  whether  one  part  had  adopted  the 
former  and  the  other  the  latter  mode  of  suspension.  To  shorten  matters, 
we  shall  begin  by  stating  that  we  entertain  the  view  that  the  Axonolipa 
were  suspended  from  seaweeds,  while  the  later  Axonophora  had  proceeded 


516 


NEW  YORK  STATE  MUSEUM 


to  a  free  or  lioloplanktonic  mode  of  existence.  This  view  is  based  on  the 
following  facts. 

In  the  Axonolipa  we  find  the  rhabdosome  in  all  cases  where  the 
proximal  parts  have  been  observed,  suspended  either  by  means  of  an 
extremely  thin,  distinctly  flexuous  nema  [p.614,  and  pl.12]  or  fastened 
directly  to  a  disk  without  the  intercalation  of  a  nema.  The  former  mode 
of  suspension  is  observed  among  the  lighter,  thin  branched  forms  and  all 
the  younger  individuals  [pl.12],  while  the  unwieldy  attachment  of  the 
base  of  the  rhabdosome  to  a  disk  occurs  among  the  mature,  heavy  branched 
forms  of  larger  dimensions,  notably  of  the  genera  Dichograptus  and 
Didymograptus  [pi.  13].  This  mode  of  attachment  is  apparently  well 
adapted  to  a  sessile  existence  on  the  underside  of  floating  seaweeds,  which 
naturally  will  be  exposed  more  or  less  to  the  commotion  of  the  surface 
waters.  The  young  lighter  forms  could  favorably  meet  these  conditions 
by  a  suspension  which  allowed  ready  yielding  to  the  movements  of  the 
water,  thus  preventing  their  being  torn  from  their  bases.  As  the  rhabdo- 
somes  grew  heavier,  a  stage  would  be  reached  where  the  thin,  flexuous 
nema  would  no  longer  furnish  a  safe  attachment,  and  a  strengthening  of 
the  same  would  lead  to  an  inflexibility  which  would  result  in  breaking 
ofl:  the  basal  stem  in  case  of  more  violent  commotions  of  the  water.  Then 
the  nema  was  gradually  discarded,  and  the  rhabdosome  began  to  hug  the 
supporting  seaweed  closely.  This  condition  is  specially  well  shown  by 
the  horizontal  Didymograpti,  as  D.  pat  ulus  and  extensus,  which, 
while  rigidly  horizontal,  attain  a  great  length.  In  them  a  nema  is  never 
observed,  Avhile  the  central  disk  has  been  seen  by  the  writer  to  be  closely 
attached  to  or  to  surround  the  apical  portion  of  the  sicula  [pi.  13].  It  is 
further  to  be  noted  that  in  the  latter  forms  the  branches  did  not  attempt  to 
assume  a  reclined  direction,  sought  by  the  others ;  and  thus  voluntarily  fore¬ 
went  the  advantage  of  giving  the  thecae  an  upward  direction,  which,  with 
the  supposed  close  attachment  to  the  underside  of  a  seaweed,  would  have 
been  a  distinct  disadvantage.  It  is  therefore  to  be  assumed  that  they  were 
attached  to  the  more  solid  portions,  the  stems  or  median  parts  of  the  leaflike 


GKAPTOLITES  OF  NEW  YORK,  PART  1 


517 


expansions  of  the  thallus  of  the  giant  seaweeds,  which  would  be  less  pliable 
and  fluctuating  with  the  waves. 

In  this  connection  the  thick  nema  of  Tetragraptus  fruticosus 
[pi.  10],  which  would  seem  to  disagree  with  the  foregoing  remarks,  deserves 
special  notice.  Complete  specimens  show  however  that  this  nema  tapers 
upward  into  a  fine  thread,  and  that  hence  also  these  beautiful  rhabdosomes 
were  suspended,  as  is  clearly  indicated  by  the  recurving  of  the  branches. 
Moreover,  in  several  cases  the  compression  of  the  organisms  has  separated 
this  apparently  thick  stem  into  two  bands,  indicating  its  hollow  character. 
It  suggests  itself  readily  that  this  secondary  expansion  of  the  nema  may 
have  been  filled  with  gas  and  to  some  extent  aided  in  supporting  the 
large  and  heavy  rhabdosome.  The  later  developed  central  disk  of  some 
Dichograptidae  appears  from  the  writer’s  observation  [p.746]  to  have  been 
composed  of  two  layers,  as  was  also  suggested  b}r  Hall ;  and  the  deposition  of 
lime  between  its  walls  described  in  this  paper  [p.746]  would  indicate  that 
it  probably  was  a  hollow  body,  the  filling  of  which  with  gas  may,  at 
times  of  accidental  separation  from  the  supporting  seaweeds,  have  saved 
the  rhabdosome  from  sinking  to  the  bottom. 

After  the  development  of  the  Dichograptidae,  and  with  them  that  of  the 
axonolipous  forms,  has  reached  its  acme  in  the  second  Deep  kill  zone,  the 
axonophorous  forms,  represented  by  Diplograptidae  and  Climacograptidae, 
appear  in  the  third  zone.  In  these  we  find  a  number  of  structural 
departures  from  the  Dichograptidae,  which  indicate  a  somewhat  different  mode 
of  existence.  These  are  the  presence  of  a  solid  axis,  which  already  originates 
in  the  wall  of  the  sicula  and  extends  into  the  nemacaulus,  as  the  present 
writer  has  shown  [  1896,  pi. 2].  In  contrast  to  the  Dichograptidae,  the 
mostly  long  nemacaulus  is  straight,  stiff  and  fragile,  as  clearly  evinced 
by  the  fact  that,  with  the  exception  of  the  synrhabdosomes  of  Diplograptus 
found  in  New  York,  nothing  but  broken  off  rhabdosomes  of  these  immensely 
common  graptolites  have  been  found.  This  character  of  the  nemacaulus 
is  incompatible  with  the  assumption  that  these  forms  could  have  lived  in 
the  agitated  waters  near  the  surface  of  the  ocean.  For  this  reason  they 


518 


NEW  YORK  STATE  MUSEUM 


must  have  lived  either  in  quiet  bottom  waters,  as  Wiman  has  urged  on 
account  of  this  stiffness  of  the  nemacaulus,  or  have  been  floating  in  some¬ 
what  deeper  and  quieter  waters  than  the  Axonolipa.  The  latter  alternative 
presents,  on  account  of  the  reversed  direction  of  growth  of  the  thecae,  the 
most  probable  hypothesis.  It  is  supported  by  other  facts  and  considerations. 
The  character  of  the  central  vesiclelike  body  in  Diplograptus  described 
before  as  pneumatophor  by  the  present  writer  [1895],  the  presence  of 
the  rudderlike  expansions  of  the  distal  ends  of  the  rhabdosomes  in  several 
species  and  the  bladelike  form  of  the  entire  rhabdosomes  of  others,  would 
suggest  the  adaptation  of  the  synrhabdosomes  to  a  vertical  and  oblique 
rising  and  sinking. 

Among  the  Axonophora  a  strong  tendency  to  a  lightening  of  the 
rhabdosomes  by  extensive  perforation  of  the  peridermal  walls,  which  finally 
leads  to  a  perfect  reticulation,  makes  itself  felt,  as  well  among  probable 
descendants  of  the  Diplograptidae  as  among  those  of  the  Climacograptidae, 
and  leads  to  the  production  of  the  genera  Retiolites,  Stomatograptus,  Grotho- 
graptus,  Lasiograptus,  Clathrograptus  and  Retiograptus.  The  purpose  of 
this  tendency  can  not  be  well  understood,  if  either  an  attachment  to  seaweeds 
or  to  the  bottom  is  assumed,  since  in  either  case  only  a  weakening  of  the 
protective  covering  without  apparent  accruing  advantage  would  be  attained ; 
but  it  is  readily  referred  to  a  planktonic  mode  of  existence,  as  all  planktonic 
forms  tend  to  lighten  their  shells. 

It  might  be  further  mentioned  that  in  certain  beds  of  the  Utica  shale  of 
the  Mohawk  valley  fragments  of  seaweeds  are  by  no  means  rare  and  are 
often  covered  with  such  organisms  as  the  sessile  Conularias,  described  by  the 
writer,  but  that  in  no  case  have  colonies  of  the  axonophorous  graptolites 
been  found  attached  to  them;  the  graptolites  occurring  in  these  beds  are, 
on  the  contrary,  only  represented  by  detached  rhabdosomes. 

Another  argument  for  the  free  planktonic  mode  of  life  of  the  Diplo¬ 
graptidae  at  least,  is  seen  by  the  present  writer  in  the  observation  published 
by  him  before  [1895],  that  the  siculae,  discharged  from  the  gonangia  are 
already  provided  with  their  pneumatophors  while  in  the  Hydroidea,  where 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


519 


an  exactly  analogous  growth  stage  is  produced  [p.523],  the  planula  is  dis¬ 
charged,  which  does  not  produce  disk,  hydrocaulus  and  first  theca  till  after 
fixation.  It  is  now  inconceivable  that  these  disks  of  the  siculae  of  Diplo- 
graptus  could  have  been  intended  as  organs  of  attachment,  as,  wherever 
attachment  of  the  embryo  takes  place  the  disk  is  formed  only  after  attach¬ 
ment  and  as  a  result  of  it.  As  the  Axonolipa  had  changed  from 
pseudoplanktonic  to  holoplanktonic  forms,  it  is  to  be  inferred  that  the  disks 
of  the  siculae  originally  were  actually  organs  of  attachment,  but  assumed 
secondarily  the  function  of  floats,  and  that  then,  by  acceleration  of  develop¬ 
ment  or  retention  and  brooding  of  the  embryos  within  the  gonothecae,  the 
disks,  which  originally  formed  only  after  contact  of  the  embryos  with  foreign 
bodies,  were  produced  within  the  gonangia. 

It  would  finally  appear  that  the  change  from  a  pseudoplanktonic 
mode  of  existence  by  attachment  to  seaweeds  to  a  holoplanktonic  mode 
would  be  easily  accomplished  by  the  accumulation  of  gas  in  some  portion 
of  the  supporting  organs.  It  would,  for  instance,  be  possible  that  a 
transudation  of  gas  took  place  into  the  space  between  the  principal  layer 
of  the  perisarc  and  the  epidermal  layer  of  the  primary  disk,  thus  pro¬ 
ducing  the  tenuous  “  pneumatophor  ”  described  by  the  writer.  Further, 
the  vesiclelike  expansions  of  the  nemacaulus  and  of  the  distal  appendages 
of  certain  species  of  Diplograptus,  as  I).  physophora,  vesiculosus 
and  la  xus  [pi.  16,  fig.  3]  are  plausibly  explained  as  organs  which  assisted 
in  floating  the  synrhabdosomes,  and  eventually  protected  the  broken-off 
rhabdosomes  from  sinking. 

7  Mode  of  reproduction  and  ontogeny 

Early  growth  stages  of  graptolites  are  of  very  common  occurrence  in 
the  graptolite  beds.  They,  therefore,  soon  attracted  the  attention  of 
observers;  and  Hall  has  figured  [1865,  pl.BJ  a  number  of  such  “germs” 
without,  however,  referring  them  to  any  definite  species.  He  also  recognized 
clearly  that  the  growth  of  the  rhabdosome  begins  with  the  minute  spinelike 


520 


NEW  YORK  STATE  MUSEUM 


body  which  he  termed  the  “  initial  point  ”  or  “  radicle,”  and  for  which 
Lapworth  later  on  introduced  the  term  “  sicula.” 

The  details  of  the  structure  of  the  sicula  have  been  elucidated  by 
Wiman,  who  has  demonstrated  that  it  consists  of  two  very  different  parts 
[see  fig.2,  2a,  2b].  The  initial  part  is  a  smooth1,  thin  walled  conical  body  that 
does  not  show  any  transversal  growth  lines  and  tapers  at  one  end  into  a 
hollow  tube,  the  nema,  while  the  other,  wider  end  is  directly  continuous 
with  the  apertural  part  of  the  sicula,  which  is  the  larger  and  thicker 


Fig. 2Diplograptus  sp.  Sicula, 
showing  the  characters  of  the  apical 
(embryonic)  and  apertural  parts. 
From  the  Baltic  sea  limestone  of 
Bornholm.  x37  (Copy  from  Wiman) 


Fig.  2a,  2b.  Obverse  and  reverse  views  of  t  he 
young  rhabdosome  of  a  dichograptid  showing 
the  sicula,  its  two  parts  and  the  gemmation  of 
the  first  theca.  From  the  Asaphus-limestone 
of  Oeland.  x27  (Copies  from  Wiman) 


walled  portion ;  is  provided  with  growth  lines  and  in  form  approaches  a 
theca.  The  sicula  has  for  this  reason  been  termed  the  first  theca  by  Holm. 

The  question  appears  pertinent,  whether  in  the  sicula  itself  (its  apical 
part)  we  have  to  see  a  product  of  sexual  reproduction  or  of  some  form  of 
gemmation.  This  leads  to  the  further  inquiry  after  the  organ  of  reproduction 
of  the  graptolites. 

Hall  believed  he  had  found  such  organs  in  appendages  of  the 
rhabdosomes  of  Diplograptus  whitfieldi  [1859,  p.507],  which 
give  the  impression  of  macerated  or  ruptured  vesicles.  But  no  siculae  were 
found  in  connection  or  inclosed  in  them ;  and  a  large  series  of  specimens  of 


Tn  Diplograptus  provided  with  longitudinal  anastomosing  thickenings. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


521 


such  forms,  collected  by  the  writer  some  years  ago  in  the  Normanskill  shale 
of  Mt  Moreno,  as  well  as  an  inspection  of  Hall’s  types  in  the  American 
Museum  of  Natural  History,  have  convinced  us  that  these  apparent 
appendages  are  of  the  character  of  the  peripheral  fibrous  tissues  of 
Lasiograptus,  as  will  be  more  fully  shown  in  the  second  memoir  on  the 
Graptolites  of  New  York.  Freeh  [1897,  p.551]  has  suggested  that  these 
appendages  may  have  been  “  Deckstiicke  ”  (protective  persons)  or  swimming 
bells  (nectophores). 

Nicholson  saw  gonangia  in  elliptic  or  orbicular  chitinous  bodies,  for 
which  he  proposed  the  name  Dawsoniae.  These  very  common  bodies  have 
however  never  been  found  attached  to  graptolite  rhabdosomes  and  form 
probably  themselves  an  aberrant  type  of  graptolites  [Appendix,  p.738]. 

Holm  and  Wiman  have  recognized  the  presence  of  small  tubes  in  the 
Dendroidea  which  flank  the  thecae,  and  asserted  the  gonangial  function  of 
these.  No  sicula  has  been  found  in  connection  with  these  tubes,  while 
distinct  siculae  occur  in  the  Dendroidea,  as  for  instance  in  Dictyonema 
flabelliforme  [pl.l].  Freeh  considers  these  tubes  homologous  to  the 
nematophores  of  the  living  Plumularidae. 

Cysts,  actually  containing  siculae,  of  two  species  of  Diplograptus, 
have  been  described  by  the  writer  [1897].  [See  text  fig.9].  These 
were  held  to  be  gonangia  or  organs  for  sexual  propagation.  Wiman  has 
expressed  his  dissenting  belief  that  they  ought  rather  to  be  considered 
individuals  of  asexual  propagation  or  budding  individuals  [1895,  p.73  ; 
1896,  p.192].  In  support  of  my  own  conception  I  would  cite  the  following 
arguments : 

1  The  homology  in  the  structure  and  development  of  the  sicula  and 
the  embryos  of  Hydroidea,  as  Eudendrium,  which  is  discussed  below 
[p.523].  The  embryos  of  Eudendrium  are,  of  course,  of  sexual  origin. 

2  Every  rhabdosome  begins  its  growth  with  a  sicula.  As  new  colonies 
among  the  recent  Cnidaria  and  other  colony-forming  invertebrates  take,  with 
rare  exception,  their  inception  from  sexually  produced  embryos,  it  is  to  be 
inferred  that  these  extinct  rhabdosomes  also  originated  from  such.  It  is 


522 


NEW  YORK  STATE  MUSEUM 


certain  that  there  was  intercalated  in  the  multiplication  of  thecae  and 
growth  of  the  colonies  by  budding  a  sexual  process  of  reproduction,  and 
this  would  be  most  na'turally  expected  to  precede  the  inception  of  new 
colonies,  or  the  formation  of  the  siculae. 

3  The  cysts  of  Diplograptus,  in  which  the  siculae  are  produced,  are  com¬ 
parable  in  structure  and  position  to  the  gonangia  or  gonothecae  of  the 
calyptoblastic  Hydroidea,  i.  e.  to  the  external,  cliitinous  receptacles  of  these 
living  forms,  in  which  either  sporosacs  or  planoblasts  are  developed.  Both 
the  sporosacs  and  planoblasts  are  generative  buds,  with  the  difference  that 
the  sporosac  remains  inclosed  within  the  gonangium,  giving  there  origin  to 
the  generative  elements  —  ova,  or  spermatozoa  —  while  the  planoblast  is  a 
generative  bud  which  is  fitted  for  a  free  locomotive  life  and  becomes 
detached  from  the  hydrosome.  As  the  product  discharged  from  the  cysts 
of  Diplograptus,  the  sicula,  directly  produces  new  colonies,  it  can  not  have 
been  a  free  generative  bud  like  the  planoblast ;  and  it  is  hence  to  be  inferred 
that  the  generative  elements  of  Diplograptus  were  produced  within  the 
gonangia,  and  that  the  ova  directly  ripened  therein  into  siculae. 

It  is  true  that,  in  the  propagation  of  Diplograptus  by  siculae,  it  has 
been  found  that  a  part  of  the  siculae  remains  attached  to  the  mother 
colony,  growing  out  directly  into  new  rliabdosomes,  while  others  are  dis¬ 
charged  with  the  evident  purpose  of  forming  new  colonies  or  synrhabdo- 
somes.  The  former  might  be  considered  as  suggesting,  by  the  retention 
of  their  connection  with  the  mother  colony,  an  asexual  origin  or  the  nature 
of  buds;  but,  then,  it  must  be  considered  that  the  colonial  stock  or 
synrhabdosome  of  Diplograptus  is  actually  a  person  of  a  still  higher  order 
than  a  common  colonial  stock  of  a  hydroid,  for  it  is  a  colony  of  colonies, 
as  each  “  stipe,”  on  account  of  its  origin  from  a  sicula,  is  homologous  with 
the  entire  colonial  stock,  or  rhabdosome,  of  a  dichograptid  or  dendroid. 

In  the  earlier  forms,  viz  the  Dendroidea  and  Graptoloidea  Axonolipa, 
the  reproduction  may  have  been  different,  in  so  far  as  no  siculiferous 
cysts  have  been  found ;  and  for  this  reason  it  is  probable  that  the  embryos 
were  discharged  at  earlier  stages.  But  the  final  product  of  the  embryonic 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


523 


development  was  also  a  sicula.  In  the  Dendroidea  it  is  possible  that  the 
flanking  tubes  of  the  thecae,  considered  by  Holm  and  Wiman  to  be 
gonangia,  contained  the  sexual  products.  In  the  Axonolipa  nothing  has 
been  found  as  yet  which  would  suggest  receptacles  for  the  development 
of  the  generative  elements ;  for  the  entire  rhabdosome  is  composed  of 
nothing  but  thecae  or  supposed  nourishing  individuals. 


Fig.  3 


Fig.  4 


Fig.  5 


Fig.  6 

Fig.  3-8 


Fig.  7  Fig.  8 

Eudendrium  ramosum  Linn.  Growthstages  (Copy  from  Allman) 


The  initial  part  of  the  sicula  is  obviously  to  be  considered  as  the  embryo 
sheath,  as  also  suggested  by  Holm. 

The  hollow  nema  is,  as  the  writer’s  shale  material  shows,  extended 
into  a  primary  disk  [pl.2].  The  complete  embryonic  shell  consists  hence  of  a 
disk  and  a  short  cone,  connected  by  a  hollow  tube.  The  question  arises, 
then,  whether  one  of  these  parts  was  formed  before  the  other  or  whether  all 
originated  together.  The  answer  to  this  problem  is  probably  furnished 
by  the  development  of  certain  hydroids,  that  pass  through  a  growth  stage 


524 


NEW  YORK  STATE  MUSEUM 


which  is  exactly  alike  in  its  structure  and  which  hence  can  be  considered  as 
equivalent  to  that  of  the  graptolites  here  under  discussion.  I  copy  here 
for  comparison  the  successive  stages  of  a  tubularian  hydroid,  Eudendrium 
ramosum,  from  Allman  [1872,  pt2,  pl.13,  fig.12-16].  The  similarity  of 
the  embryos  in  the  graptolites  and  this  hydroid  is  increased  by  the  fact 
that  the  embryo  of  the  latter  produces  a  delicate  chitinous  sac.1 

In  figure  4  the  planula  has  “become  fixed  by  a  disklike  enlargement 
of  one  extremity.” 

In  figure  5  “  the  disk  of  fixation  has  become  more  decidedly 
differentiated,  while  a  delicate  chitinous  perisarc  has  become  excreted  over 
the  whole  surface  of  the  embryo.” 

In  figure  6  “  the  disk  has  begun  to  be  divided  into  radiating  lobes,  and 
the  hypostoma  has  become  differentiated.” 

In  figure  7  “  the  hydranth  is  now  distinctly  differentiated  from  the 
hydrocaulus,  while  the  tentacles  have  begun  to  sprout  round  the  hypostoma, 
and  within  a  delicate  chitinous  sac,  which  envelops  the  whole.” 

In  figure  8  “the  hydranth  has  attained  to  nearly  its  ultimate  form, 
and  has  burst  through  the  chitinous  sac,  which  has  hitherto  confined  it, 
and  the  tentacles  are  now  free  to  extend  themselves  in  the  surrounding 
waters.” 

There  is  no  visible  ground  for  the  assumption  that,  inasmuch  as  the 
embryo  of  the  graptolite  shows  the  same  composition  of  disk,  nemacaulus 
and  conical  sheath,  the  formation  of  its  embryonic  sheath  did  not  take  place 
by  the  same  processes  of  differentiation  of  an  originally  saclike  covering 
into  a  disk  and  closed  cone,  and  the  gradual  lengthening  of  the  apical  part  of 
the  cone  into  a  nemacaulus. 

After  the  bursting  of  the  embryonic  sac,  the  zooid  began  to  grow  and 
formed  the  apertural  part  of  the  sicula,  the  increment  producing  the  trans¬ 
versal  growth  lines. 

^he  presence  of  the  chitinous  covering  of  the  embryo  in  the  graptolites  has 
repeatedly  been  cited  as  an  important  difference  from  the  hydroids  [p.576],  but,  as  this 
instance  shows,  without  propriety. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


525 


In  the  only  case,  where  the  organ  containing  the  siculae  has  been 
observed,  viz  in  Diplograptus  foliaceus,  it  has  been  found  that 
these  originate  in  cysts,  which  surround  the  base  of  the  whole  svnrhabdosome 
[p.528],  and  that  they  are  partly  retained,  growing  out  into  new  rhabdosomes, 
and  partly  discharged,  producing  new  synrhabdosomes.  Here  the  young 
pass  therefore  apparently  within  vesicles  through  postembryonic  stages,  which 
in  the  Hydroidea  are  passed  only  after  fixation  of  the  embryo.  This  is 
evidently  a  secondary  adaptation  to  the  free  planktonic  mode  of  life  of  the 
Axonophora. 

The  fact  that  no  such  sicula-bearing  vesicles  have  been  found  attached 
to  any  of  the  frequently  observed  rhabdosomes  of  the  Dichograptidae 
would  indicate  that  in  these  forms,  which  were  pseudoplanktonic,  the  young 
were  discharged  already  in  their  planula  stage,  and  the  subsequent  growth 
stages  were  passed  after  attachment  to  foreign  bodies,  as  in  the  living 
Hydroidea. 

The  sicula  has  been  termed  the  first  theca  by  Holm.  While  Wiman’s 
investigations  have  taught  us  that  the  apertural  part  of  the  sicula,  indeed, 
has  the  form  and  function  of  a  theca,  it  can  also  be  inferred  from  his 
work,  that  it  still  differs  in  essential  characters  from  all  later  thecae  of  the 
same  rhabdosome.  Thus  in  Diplograptus  there  is  formed  a  solid  axis,  the 
virgula,  in  the  wall  of  the  sicula,  which  is  lacking  in  the  other  thecal  walls, 
and  the  aperture  is  provided  with  a  long  spine  (the  distal  extension  of  the 
axis)  on  one  side,  and  with  two  lobes  on  the  opposite.  All  of  these  characters 
fail  to  develop  on  the  thecae.  Elles’s  and  Wood’s  and  the  writer's  investiga¬ 
tions  have  further  demonstrated  that  the  siculae  frequently  differ  in  their 
dimensions  from  the  thecae  of  the  same  rhabdosome.  It  is  therefore  to  be 
inferred  that  the  first  zooid,  occupying  the  sicula,  must  have  differed  in 
essential  characters  from  the  later  individuals  produced  by  gemmation.  It 
is,  for  this  reason,  appropriate  to  designate  this  first  theca  always  by  a  special 
term,  viz  sicula. 

The  presence  of  a  rod  in  one  side  of  the  sicular  Avail  and  that  of  the  tAvo 
lobes  on  the  opposite  side  of  the  aperture  gives  to  the  sicula  a  particularly 


526 


NEW  YORK  STATE  MUSEUM 


conspicuous  bilateral  symmetry,  as  Wiman  has  pointed  out  [1893,  p.269] 
This  author  lays  great  emphasis  on  this  fact  in  the  discussion  of  the  possible 
relations  of  the  graptolites  to  the  Hydroidea,  and  we  shall  recur  to  this 
character  in  a  later  chapter  [p.576]. 

Lapworth,  as  early  as  1876,  when  describing  two  species  of  the  new 
genus  Dimorphograptus,  expressed  his  belief  that  the  sicula  never  develops 
more  than  one  bud,  even  in  the  diprionidian  forms.  This  view  has  been 
confirmed  by  Holm’s,  Wiman’s  and  the  writer’s  observations  on  represen¬ 
tatives  of  different  orders  of  the  graptolites,  and  it  can  now  be  asserted  that 
in  all  graptolites  but  one  bud  originates  from  the  sicula. 

With  this  the  process  of  continuous  budding  is  initiated,  which  results 
in  the  formation  of  the  rhabdosomes. 

Series  of  growth  stages  of  colonies  have  thus  far  been  published  only  by 
the  present  writer,  viz  those  of  the  synrhabdosomes  of  Diplograptus 
foliaceous  [1895]  and  of  the  rhabdosomes  of  Goniograptus  thu- 
reaui  [1902,  p.576-93],  to  which  is  added  in  this  publication  a  series  of 
the  growth  stages  of  Dictyonema  flabelliforme.  It  thus  happens 
that  these  represent  the  three  orders  of  graptolites,  the  last  named  graptolite 
giving  an  example  of  the  development  of  the  Dendroidea,  Goniograptus 
thureaui  of  the  axonolipous  Graptoloidea,  and  Diplograptus  foli- 
aceus  of  the  axonophorous  Graptoloidea. 

The  astogenetic  series 1  of  Dictyonema  flabelliforme  is  described 
in  greater  detail  under  that  species.  We  shall,  therefore,  mention  here  but 
the  principal  facts.  It  begins  with  a  distinct  sicula,  provided  with  a  very 
long  nema  and  a  primary  disk  [pl.l,  fig.l].  From  the  sicula  buds  first  a 

1  We  adopt  here  a  recent  suggestion  by  Dr  E.  R.  Cumings  [Development  of  Some 
Paleozoic  Bryozoa.  Am.  Jour.  Sci.  1904.  17:50],  who  submits  a  new  set  of  terms  for 
the  growth  stages  of  a  colony  in  distinction  to  those  introduced  by  Hyatt  for  the  ages  of 
an  individual,  and  shall  use  here  the  term  astogenetic  series  for  these  growth  stages  of  a 
colony.  In  a  former  paper  [1902,  p.591],  in  which  for  the  first  time  has  been  pointed 
out  the  recognition  of  stages  in  the  development  of  a  colony  which  correspond  to  the 
ontogenetic  growth  stages  of  an  individual,  we  have  employed  the  terms  of  the  latter 
series  in  a  wider  sense. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


527 


single  theca,  which,  however,  as  Wiman’s  sections  of  rhabdosomes  of  other 
species  of  Dictyoneraa  would  suggest,  is  probably  of  a  composite  nature  and 
consists  of  a  nourishing  individual  and  a  budding  individual.  It  thus  repre¬ 
sents  already  a  branch.  This  first  branch  diverges  at  an  approximately 
right  angle  from  the  sicula.  Several  more  buds  of  thecal  appearance  and 
apparently  composite  nature  originate  in  succession,  one  from  the  other,  all 
arranging  themselves  around  and  close  to  the  sicula,  thus  producing  a  whorl 
of  branches  radiating  from  the  apertural  part  of  the  sicula  [pl.l,  fig.13,  15]. 
These  branches  of  the  first  order  at  once  give  origin  by  dichotomy  to 
branches  of  a  higher  order,  which  continue  the  same  process.  Thus  is 
produced  the  multitude  of  straight  branches,  which,  growing  downward 
and  outward,  arrange  themselves  on  the  surface  of  an  imaginary  bell. 

With  the  astogenetic  development  of  a  midtiramous  colony  of  the 
axonolipous  Graptoloidea ,  we  have  become  acquainted  by  the  material  of 
Goniograptus  thureaui  from  the  Deep  kill.  The  astogenetic  series 
of  this  form  has  been  described  in  the  New  York  State  Museum  bulletin 
52;  aud  is  more  fully  treated  in  this  memoir  under  that  species  [p.621  and 
pi. 6].  It  represents  a  type  of  development  different  from  that  of 
Dictyonema  flabelliforme  in  several  features,  while  it  can  be  said 
to  be  typical  of  the  whole  mass  of  Dichograptidae. 

From  the  sicula  a  single  theca  buds,  which  is  noncomposite  and  turns 
to  one  side  in  a  horizontal  direction.  From  this  theca  originates  a  second 
theca,  which,  falling  into  the  same  line  with  the  first  theca,  turns  in  oppo¬ 
site  direction.  These  first  two  thecae  form  the  crossbar  at  the  center  of 
all  the  dichograptid  rhabdosomes,  "which  has  been  termed  the  “  funicle  ” 
by  Hall,  and  which  hence  is  composed  of  thecae  like  the  rest  of  the 
colony. 

Both  of  the  first  two  thecae  divide  again  dichotomously,  producing  thus 
four  branches  of  the  second  order,  which  repeat  the  same  process,  the  result 
being  eight  branches  of  the  third  order. 

After  this  stage  is  reached,  in  one  half  of  the  branches  the  thecae 
adopt  a  serial  arrangement  these  becoming  the  “  denticulate  ”  branches  of 


528 


NEW  YORK  STATE  MUSEUM 


the  earlier  authors,  while  the  others  continue  to  bifurcate,  forming  the 
so  called  stems.  Both  kinds  of  branches  consist  of  thecae. 

The  early  stages  of  all  multiramous  Dichograptidae  are  identical  -with 
those  of  Goniograptus.  . 

A  third  series  of  growth  stages,  found  in  the  New  York  rocks,  is  that  of 
Diplograptus  foliaceus.  This  again  is  representative  of  the  axono- 
phorous  Graptoloidea  and  differs  fundamentally  from  either  of  the  two 
mentioned  before.  It  has  been  fully  described  and  figured  in  the  14th 


Fig.  9  (1-8)  Diplograptus  foliaceus  McCoy.  Series  of  growth  stages,  g,  gonangium ;  pn,  pneu- 
matophor;  I,  first  generation  of  rhabrtosomes ;  II,  second  generation  (Copy  from  Kuedemann) 


Annual  Report  of  the  New  York  State  Geologist  [pi. 3].  We  copy  here  the 
drawings  of  some  of  the  most  characteristic  stages.  These  show  that  the 
growth  of  the  synrhabdosome  of  that  diplograpticl  also  begins  with  a  sicula 
provided  with  nemacaulus  and  disk  [ see  fig.9]. 

From  the  sicula  originates  again  a  single  theca  [see  fig.9-2].  This,  as 
AY i man  has  demonstrated  [see  fig.  10]  grows  for  a  short  distance  downward 
in  the  direction  of  the  sicula,  but  then  turns  abruptly  aside  and  the  next 
theca  grows  upward  along  the  sicula  in  a  proximal  or  antisicular  direction 
and  turns  to  the  opposite  side  of  the  sicula.  A  continuation  of  this  process 
of  budding  and  alternate  arranging  of  thecae  produces  the  first  stipe,  which 
apparently  consists  of  two  separate  series  of  thecae  [ see  fig.9-4]. 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


529 


As  the  writer  has  pointed  out  in  the  paper  mentioned,  the  thecae,  and 
with  them  the  entire  rhabdosome,  grow  along  the  nemacaulus  toward  the 
central  organs,  hence  in  a  direction  directly  opposite  to  that  found  in  the 
typical  Dichograptidae.  The  nemacaulus  itself  lengthens  rapidly  [see  fig.9-4] 
Before  the  primary  rhabdosome  has  reached  mature  size,  cysts  appear 
around  the  base  of  the  nemacaulus  on  the  primary  disk  [ see  fig.9-4], 
which  in  older  specimens  are  filled  with  siculae  [see  fig.9-5].  These 
cysts,  which  have  been  termed  gonangia  by  the  writer  and  considered  vesicles, 
containing  the  products  of  sexual  reproduction,  open  finally,  a  part  of  the 
siculae  is  discharged  and  form  new  separate 
rhabdosomes,  while  the  others  remain  in  con¬ 
tact  with  the  primary  disk  and  evolve  in  the 
same  fashion  as  the  primary  rhabdosomes  into 
new  rhabdosomes  [see  fig.9-7],  thus  producing 
the  radiating  groups  of  rhabdosomes.  Succes¬ 
sive  generations  of  gonangia  produce  whorls  of 
rhabdosomes  which  differ  in  length,  each  whorl 
representing  the  rhabdosomes  grown  from  a  dif¬ 
ferent  generation  of  siculae  [see  fig.9-8]. 

of  the  rhabdosomes  of  the  axonophorous  Grapto- 
loidea  differs  in  the  following  facts  from  that  of  the  axonolipous  Graptoloidea. 
The  nemacaulus  of  the  sicula  becomes,  by  the  retrograde  growth  of  the 
thecae,  incorporated  into  the  rhabdosome  as  a  part  of  the  axis,  while  in  the 
Dendroidea  and  axonolipous  Graptoloidea  it  remains  free.  The  primary 
rhabdosome  with  its  one  stipe  is  homologous  with  the  entire  colony  of  the 
Dendroidea  and  axonolipous  Graptoloidea,  as  it  is  produced  by  one  sicula. 
As  new  rhabdosomes,  each  originating  from  a  sicula,  combine  in  Diplograptus 
into  a  composite  colonial  stock,  this  represents  a  rhabdosome  colony  or  a 
person  of  a  higher  order  than  that  of  the  Dendroidea  and  Dichograp¬ 
tidae,  and  the  writer  [see  ch.4,  p.483]  has  hence  proposed  for  it  the  term 
synrhabdosome. 


It  will  be  noticed  that  the  development 


Fig.  10  Diplograptus  sp.  Aper- 
tural  part  of  sicula  and  first  theca, 
showing-  the  perforation  from  which 
the  second  theca  will  grow.  .\3~  (Copy 
from  Wiman) 


530 


NEW  YORK  STATE  MUSEUM 


It  has  been  pointed  out  by  the  writer  in  a  former  publication  [1902, 
p.586ff]  that  not  only  did  there  exist  in  the  graptolites  ontogenetic  growth 
stages  in  the  development  of  the  individual  zooids,  which,  however,  can  not 
be  traced  in  the  fossils,  but  the  rhabdosomes  in  toto  and  their  parts,  the 
branches,  seem  also  to  pass  through  stages  lohich  suggest  phylogenetically 
preceding  forms.  These  ontogenetic  stages  of  the  rhabdosomes  express 
themselves  in  various  ways,  of  which  we  select  here  the  direction  of  the 
branches  and  the  changing  character  of  the  thecae. 

The  original  direction  of  the  growth  of  the  branches  in  the  Dichograp- 
tidae  has  been  in  the  approximate  continuation  of  the  sicula,  i.  e.  an  ascending 
erect  position  as  long  as  the  rhabdosomes  were  sessile  on  the  ground.  These 
became  pendent  [ see  ch.6,  p.51 3]  when  the  graptolites  attached  themselves 
in  a  suspended  position  to  seaweeds,  as  numerous  hydroids  do  today.  To 
restore  to  the  zooids  their  original,  more  advantageous,  erect  position,  the 
branches  began  now  to  recurve,  a  process  which  in  the  Dichograptidae  led  to 
the  Phyllograptidae,  the  horizontal,  the  reflexed,  reclined  and  recumbent 
Tetragraptidae  and  Didymograptidae  [see  ch.10,  p.543],  and  to  the  whole  class 
of  the  Axonophora,  where  the  thecae  climb  upward  along  the  nemacaulus. 

We  find  now  in  the  majority  of  the  Dichograptidae  with  the  above  cited 
growth  directions  of  the  branches,  that  the  latter  still  retain  their  original 
dependent  direction,  in  the  proximal  parts  in  some  species,  as  in  T  e  t  r  a  - 
graptus  fruticosus  [pl.10,  fig.l],  Didymograptus  nitidus, 
D.  tornquisti  and  D.  patulus,  while  in  others,  by  the  law  of 
acceleration,  the  dependent  proximal  direction  has  already  changed  into  a 
horizontal  one,  as  in  Tetragraptus  serra,  bigsbyi  and  taraxa¬ 
cum,  the  change  in  direction  becoming  progressively  more  abrupt  as  the 
final  direction  of  the  branches  becomes  reclined,  as  in  T.  bigsbyi,  or 
recumbent,  as  in  Phyllograptus. 

In  the  Axonophora,  where  the  growth  direction  of  the  rhabdosome  has 
become  entirely  recumbent,  it  growing  upward  along  the  nemacaulus,  only 
the  first  theca  retains  for  a  short  distance  the  original  downward  direction, 
and  then  turns  abruptly  in  a  direction  at  right  angles  to  the  former.  The 


GRAPTOLITES  OF  NEW  YORK.  PART  1 

branches  pass  hence,  in  their  development,  through  dif¬ 
ferent  directions  representing  ontogenetic  stages  that 
repeat  stations  in  their  phylogenetic  development. 

An  analogous  fact  is  found  in  the  character  of  the 
thecae.  The  change  which  takes  place  in  the  character  of 
the  thecae  within  the  colonies  of  the  Dichograptidae  has 
been  described  in  detail  in  the  paper  noted  before,  on  the 
development  of  Goniograptus  thureaui  [1902, 
p.586].  The  writer  has  endeavored  to  demonstrate  that 
in  the  rhabdosomes  of  that  species  two  different  kinds 
of  thecae  can  be  recognized,  (1)  those  in  the  more 
proximal  portions  forming  the  bifurcating  branches,  for 
which  the  term  stolonal  thecae  was  proposed,  and  (2) 
those  in  the  distal  parts,  notably  in  the  serially  arranged 
final  branches.  These  were  termed  brachial  thecae.  The 
stolonal  thecae  are  more  cylindric  than  the  brachial 
ones,  remain  narrower  toward  the  aperture,  less  inclined 
to  the  axis  of  the  branches  and  without  any  submucro- 
nate  apertural  processes. 

A  comparison  of  the  form  of  the  thecae  of  the 
younger  clichograptid  genera,  as  of  Dichograptus,  Tetra- 
graptus  and  Didymograptus,  with  that  of  the  older  and 
presumably  phylogenetically  preceding  genera,  Bryograp- 
tus  and  Clonograptus,  shows  that  in  general  the  older 
genera  have  the  more  tubular,  simpler  thecae  with  less 
protected  apertural  margins.  It  is,  hence,  apparent  that 
the  stolonal  or  earlier  thecae  of  the  rhabdosomes  repre¬ 
sent  indeed  the  older  types  of  thecal  form. 

Observation  of  the  thecae  constituting  the  “  denticu¬ 
late  ”  or  final  branches  of  Goniograptus  thureaui, 
of  Tetragraptus  fruticosus  [see  fig.ll],  and  of 
T.  taraxacum  has  further  brought  out  the  fact  that 

O 


531 


gressive  change  of  thecae. 
x:ib  (Copy  from  Ruede- 
man) 


532 


NEW  YORK  STATE  MUSEUM 


within  these  branches  also  a  gradual  change  of  the  thecae  from  the  stolonal 
or  siculoid  form  to  the  brachial  one  takes  place.  In  the  species  of  Gonio- 
graptus  cited,  it  has  been  shown  that  the  earlier  thecae  of  the  branches 
have  an  inclination  of  but  7°  as  against  28°  in  the  more  distal,  mature 
thecae,  and  overlap  but  one  fourth  of  their  length,  whereas  the  later  ones 
overlap  more  than  one  half  and  have  straight  apertures  without  marginal 
processes ;  these  also  have  concave  apertures  with  projecting,  outer  apertural 
margins. 

It  has  been  concluded  from  these  facts  that  “  the  thecae  of  the  colony  of 
Goniograptus  (and  other  Dichograptidae  as  well)  from  the  sicula  through  the 
stolonal  and  early  brachial  thecae  to  the  distal  brachial  thecae,  form  an 
ontogenetic  series,  which  furnishes  a  clear  and  interesting  example  of 
localized  stages  of  development,”  the  existence  of  which  has  been  demon¬ 
strated  and  their  character  elucidated  by  R.  T.  Jackson1.  The  principle  of 
the  localization  of  development  expresses  the  fact  that  “  in  organisms  that 
grow  by  a  serial  repetition  of  parts,  it  is  found  that  there  is  often  an 
ontogenesis  of  such  parts  which  is  more  or  less  clearly  parallel  to  the 
ontogenesis  of  the  organism  as  a  whole.” 

The  asexually  produced  buds  of  the  graptolites  (thecae),  like  those  of 
Hydrozoa  and  Actinozoa,  are  now  to  be  considered  as  such  localized  stages. 
While  they  lack  the  stages  seen  in  early  embryonic  development,  they 
repass  in  general  the  later  stages  found  in  the  ontogeny  of  sexually  produced 
young. 

The  application  of  Jackson’s  principle  to  the  colony  of  Goniograptus 
hence  allows  the  conclusion  “  that  the  branches  of  the  rhabdosome,  like  the 
leaves  of  a  tree,  indicate  individually  by  their  ontogeny  the  path  along  which 
they  have  been  developed.  The  ontogeny  of  the  branches  demonstrates 
that  the  phylogenetically  preceding  forms  possessed  branches  composed  of 
more  tubular  thecae,  with  less  overlap,  looser  arrangement,  smaller  deviation 
from  the  direction  of  the  axis  of  the  branch  and  straight,  not  mucronate 
apertures.” 


1  Bost.  Soc.  Nat.  Hist.  Memoir.  1899.  v.5,  no.4. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


.  533 


On  the  other  hand,  Didymograptus  gracilis,  a  form  with 
extremely  long  filiform  thecae  in  the  mature  stage,  possesses  in  its  proximal 
part  shorter,  tubular  thecae,  of  the  Bryograptus  type  of  thecal  structure, 
thus  indicating  an  opposite  path  of  development  to  that  observed  in 
Goniograptus,  but  which  also  finds  its  expression  in  the  ontogenetic  develop¬ 
ment  of  the  branch  [see  fig.  12]. 

As  noted  before,  the  directions  of  the  branches  in  the  proximal  parts 
present  also  an  ontogenetic  development,  indicative  of  phylogenetic  stages 
passed.  Both  the  direction  of  the  branches  and  the  character  of  the 
thecae  tend,  hence,  to  support  the  same  view,  viz  that  the  branches,  though 
composed  of  thecae  were  connected  into  physiologic  units. 


Fig.  12  Didymogniptus  g r a c i  1  i s  Tornquist.  Enlargement  of  the  specimen 
figured  on  plate  14,  figure  17  to  show  more  distinctly  the  sicula  and  the  progres¬ 
sive  lengthening  of  the  thecae.  Deep  kill.  x6 


The  writer  has  endeavored  to  demonstrate  in  the  paper  on  Goniograptus 
that,  not  only  the  branches,  but  in  fact  the  entire  colonies  of  graptolites 
were  organisms  approaching  closely  to  the  character  of  individuals.  One 
finds  among  the  colonies  all  gradations  from  loose  aggregates  of  individuals 
forming  colonies  to  organisms  in  which,  by  division  of  labor,  consequent 
suppression  of  individuality  and  the  presence  of  common  organs,  the  colony 
also  morphologically  approaches  closely  to  the  character  of  a  sole  individual, 
as  in  the  Siphonophora. 

The  graptolite  rhabdosomes  now  present,  besides  the  ontogenetic 
characters  of  the  proximal  parts  described  above,  various  other  features, 
which  are  suggestive  of  the  physiologic  individuality  of  the  colonies.  Some 
of  these  are  the  presence  of  a  common  float  or  pneumatophor,  observed 
in  several  groups,  and  the  geometric  arrangement  of  the  branches,  which 


534 


NEW  YORK  STATE  MUSEUM 


became  progressively  more  rigid  and  which  served  to  maintain  the 
equilibrium  and  to  give  to  the  greatest  number  of  zooids  the  most  advan¬ 
tageous  position. 

As,  now,  the  graptolite  rhabdosome  so  closely  approached  the  character 
of  an  individual,  and  like  such  a  one  had  its  ontogeny  and  repassed 
ancestral  stages,  it  is  possible  to  recognize  such  ontogenetic  stages  of  the 
whole  rhabdosome  and  to  apply  to  these  the  terminology  introduced  by 
Hyatt  for  the  ontogenetic  series  of  an  individual.  These  stages  have  to 
some  extent  been  traced  in  the  rhabdosomes  of  Goniograptus  with  the 
following  result1 : 

The  embryonic  stage  is  clearly  present  in  the  initial  part  of  the  sicula, 
which  is  differentiated  from  the  distal  part  of  the  sicula  by  the  nature  of 
the  periderm,  which  is  thin,  pellucid  and  possesses  no  growth  lines.  Holm 
asserts  his  belief  that  this  initial,  more  pointed  end  of  the  sicula  “  corre¬ 
sponds  to  the  original  chitinous  covering  of  the  free  zooid  germ  or  embryo.” 
It  holds  a  position  similar  to  the  protoconch  of  the  cephalopod  shell. 
The  nepionic  or  infantile  stage  is  represented  by  forms  [pi. 7,  fig.1-6]  in 
which  the  successive  dichotomous  divisions  produce  the  stems.  It  begins 
with  the  formation  of  the  apertural  part  of  the  sicula.  The  neanic  or 
adolescent  stage  of  the  colony  begins  with  the  formation  of  the  branches 
with  serial  arrangement  of  thecae  and  ends,  in  the  Goniograptus  material 
from  the  Deep  kill,  with  the  production  of  six  such  branches  on  each  of 
the  four  stems.  After  this,  in  the  ephebic  or  mature  stage,  the  branches 
continue  to  grow  out  to  full  length.  The  gerontic  or  senile  age  is  marked 
by  a  thickening  of  the  stems. 

8  Structure  and  morphology 

As  much  of  the  structure  and  morphology  of  the  graptolites  has  been 
anticipated  in  preceding  chapters,  and  more  details  are  given  in  the  generic 
descriptions,  but  a  cursory  statement  of  the  principal  facts  regarding 

1  As  we  have  before  noted,  Professor  Cutnings  has  meanwhile  proposed  to  desig¬ 
nate  the  growth  stages  of  colonies  by  the  prefix  “asto.” 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


535 


those  groups  of  graptolites  which  are  treated  in  this  memoir  is  needed  in 
this  place. 

All  graptolites  are  colonies  of  hydroid-like  appearance.  Only  the  car¬ 
bonaceous  (chitinous)  periderm  is  preserved. 

Probably  all  colonies  originated  from  an  embryonal  zooid  (sicula)  and 
consisted,  where  complete,  of  (1)  the  organs  of  attachment,  or  suspension, 
(2)  the  supporting  stems,  (3)  the  thecae,  and  (4)  the  reproductive  organs. 

The  organ  of  attachment  may  be  a  part  of  the  first  embryonal 
zooid  (primary  disk)  or  a  secondary  disk  (central  disk)  or  a  rootlike 
expansion.  The  first  organ  is  probably  found  in  the  young  stages  of  all 
graptolites,  and  in  the  mature  stage  of  all  smaller  Axonolipa  and  probably 
in  all  Axonophora ;  the  second  in  some  larger  forms  of  the  Dichograptidae 
(genera  Tetragraptus  and  Dichograptus).  Perhaps  it  occurs  also  in  some 
species  of  Didymograptus,  as  in  D.  p  a  t  u  1  u  s .  The  rootlike  expansions 
have  been  observed  only  in  some  Dendroidea  ( see  Dictyonema).1 

Between  the  sicula  and  the  primary  disk  is  intercalated  either  a  thin, 
often  very  long,  filament,  the  nema,  in  the  young  of  some  Dendroidea 
(D  ictyonema  flabelliforme)  and  the  Axonolipa,  or  a  more  rigid, 
narrow  tube  (nemacaulus)  in  the  Axonophora,  which  in  the  latter  is 
(always?)  supported  by  a  strengthening  rod  (virgula)2  originating  in  the 
wall  of  the  sicula. 

From  the  sicula  originates  the  first  theca,  and  by  continued  gemmation 
of  thecae  the  branches  are  formed.  The  second  theca  in  nearly  all  Grapto- 

1  In  some  Axonophora  a  vesicle  has  been  found  by  the  writer  to  surmount  the 
primary  disk.  This  is  considered  to  have  had  the  function  of  a  pneumatophor. 

2  The  inclosure  of  the  virgula  within  the  nemacaulus  of  the  Diplograptidae  can  be 
inferred  from  an  observation  made  by  the  writer  [1895],  who  found  in  a  flexed  specimen, 
that  the  virgula  had  separated  from  the  nemacaulus  \loc.  cit.  pi. 2,  fig.6].  The  latter 
is,  according  to  Wiman,  who  observed  its  initial  part,  a  hollow  tube.  Sometimes 
the  nemacaulus  becomes  inflated  into  a  vesicle,  as  in  Dipl,  appendiculatus 
(Tornq.  ms.)  Elies  emend.  Inside  this  vesicle  the  virgula  can,  according  to  Elies  [1898] 
be  quite  well  detected ;  and  it  is  also  figured  [ibid.  fig.  30]  by  that  authoress  as  a  straight 
rod  extending  through  the  vesicle. 


NEW  YORK  STATE  MUSEUM 


536 

loidea  (with  the  exception  of  unbranched  forms,  as  Azygograptus)  crosses 
over  and  places  itself  on  the  opposite  side  of  the  sicula.  This  often 
prominent  proximal  part  of  the  second  theca,  which  in  the  multiramous 
forms  connects  the  common  canals  of  the  first  four  branches,  has  been  termed 
connecting  canal  by  Ilolm,  but  this  term  was  applied  by  Tornquist  to  the 
first  part  of  the  first  theca.  Elies  and  Wood  call  it  the  “crossing  canal.” 

In  the  Dendroidea  the  branches  consist  of  three  different  kinds  of  tubes : 
large  thecae,  which  are  supposed  to  have  contained  nourishing  individuals, 
smaller  tubes,  which  are  budding  individuals,  and  from  which  all  three  kinds 
of  tubes  originate,  and  longer,  narrow  tubes  (gonangia,  after  Holm  and 
Wiman;  nematophores,  according  to  Freeh).  For  further  details  see  under 
Dictyonema  and  Dendrograptus. 

In  the  Graptoloidea  only  thecae  of  one  kind  are  observable  which 
contained  nourishing  zooids.  These  exhibit  in  some  compound  Dichograp- 
tidae  (Goniograptus,  Tetragraptus)  certain  differences  proceeding  from  the- 
base  of  the  colony  in  a  distal  direction,  which  are  of  an  ontogenetic  character 
[see  ch.7,  p.531].  The  apertures  of  the  thecae  are  often  provided  with  one  or 
several  mucros  or  spines.  These  and  other  characters  give  to  the  theca  a 
bilateral  symmetry.  The  external  and  internal  apertures  of  the  thecae  are 
in  most  or  perhaps  all  Graptoloidea  provided  with  a  ringlike  thickening 
[see  Perner,  text  fig.  1 ,  2,  and  H i d y  m ograptus  b i f  i d u s ,  p.692,  of  this 
publication]. 

In  the  axonolipous  Graptoloidea  the  thecae  grow  in  a  distal  direction 
and  are  connected  and  held  by  their  bases  only,  which  form  a  continuous 
canal  (common  canal).  In  the  Axonophora  the  first  theca  assumes,  after  a 
short  distal  growth,  a  reverse  direction,  which  is  followed  by  all  succeeding 
thecae.  These  attach  themselves  to  the  nemacaulus.  The  latter  is  here 
supported  by  an  independently  formed  axis  (virgula). 

It  appears  that  also  in  the  heavier  branches  of  the  Axonolipa,  as  in 
Tetragraptus  amii  [see  pl.ll,  fig.l]  a  support  of  the  branches  was 
obtained  by  a  thickening  of  the  dorsal  wall  (common  canal)  of  the  branches. 

The  branching  of  the  rhabdosomes  takes  place  in  different  ways.  In 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


537 


Dictyonema,  according  to  Wiman,  a  generation  preparative  to  a  branching 
produces  a  theca  and  two  budding  individuals  instead  of  a  theca,  a  budding 
individual  and  a  gonangium.  Each  of  the  budding  individuals  then 
produces  the  three  kinds  of  individuals ;  the  resulting  two  groups  of 
individuals  forming  with  one  or  more  of  the  old  thecae,  the  new  branches, 
which  are  thus  of  perfectly  dichotomous  origin.  In  the  forms  referred  by  the 
same  author  to  Dendrograptus  the  process  is  essentially  the  same.  In 
Inocaulis  one  has  to  differentiate  between  branches  and  branchlets  or 
twigs.  Each  of  the  latter  consists  of  four  individuals,  two  thecae  and  two 
gonangia,  which  originate  in  the  branches  and  open  on  the  twigs.  In  Cal- 
lograptus  the  mode  of  the  formation  of  branches  is  not  yet  known. 

In  the  axonolipous  Graptoloidea  branching  is  accomplished  by  two 
successive  thecae,  which  turn  to  different  sides  and  thus  become  the  mother 
thecae  of  new  branches.  In  the  early  axonophorous  Graptoloidea,  described 
in  this  publication,  no  branching  takes  place  within  the  rliabclosomes  or 
persons  of  the  second  order. 

The  arrangement  of  the  branches  varies  greatly  in  the  Dendroidea ;  the 
branches  are  distributed  irregularly  in  treelike  fashion  in  Dendrograptus, 
arranged  into  a  funnel  or  bell-shaped  rhabdosome  in  Dietyonema,  into  a  similar 
or  probably  flabellate  form  in  Callograptus,  while  in  Ptilograptus  the 
irregularly  arranged  branches  are  plumose,  the  branchlets  rising  alternately 
on  opposite  sides  of  the  branches. 

In  the  axonolipous  Graptoloidea  the  earliest  genera,  Clonograptus  and 
Bryograptus,  possess  an  irregular  arrangement  of  the  branches.  From  these 
two  develop,  by  a  progressive  reduction  in  the  number  of  branches,  forms 
with  a  regular  disposition  of  the  branches,  namely  the  genera  Loganograptus, 
Dichograptus,  Tetragraptus,  Didymograptus  and  Phyllograptus,  forming  one 
group,  the  genera  Sigmagraptus,  Coenograptus,  Pterograptus  and  Pleuro- 
graptus  another,  and  the  genera  Temnograptus,  Schizograptus,  Ctenograptus, 
Holograptus,  Itouvilligraptus  and  Trochograptus,  a  third. 

In  the  first  group  only  dichotomous  branching  is  observed,  in  the  others 
the  dichotomous  and  monopodial  modes  of  branching  form  various  combina- 


538 


NEW  YORK  STATE  MUSEUM 


tions.  While  the  two  modes  of  branching  produce  very  different  appearances 
of  rliabdosomes,  there  exists  probably  no  essential  difference  between  them. 
In  one  case  the  mother  theca  produces  a  daughter  theca,  so  early  that  it  has 
not  progressed  sufficiently  to  force  the  latter  into  a  new  direction,  but  both 
assume  new  directions,  while  in  the  monopodial  branching  the  mother  theca 
has  already  established  its  direction,  that  of  the  preceding  branch,  when 
it  sends  out  a  daughter  theca,  which  then  alone  diverges  from  the  old 
direction. 

Within  the  Dichograptidae  the  angle  of  divergence  changes  within  the 
whole  compass  of  the  circle,  a  complete  reversion  in  the  direction  of  the 
branches  gradually  taking  place.  This  fact  will  be  noted  more  fully  in  the 
chapter  on  the  classification  and  phylogeny  of  the  graptolites. 

The  structure  of  the  rliabdosomes  of  the  graptolites  with  diprionid 
arrangement  of  the  thecae,  sucli  as  the  Diplograptidae  and  Climacograptidae 
have,  has  been  little  understood  till  recent  years,  but  it  is  now  known  that,  as 
a  rule,  and  notably  in  Diplograptus,  the  rhabdosome  is  composed  of  thecae 
wTich  have  assumed  a  proximal  or  centripetal  direction  of  growth  along  the 
nemacaulus  of  the  sicula,  whereby  each  theca  buds  from  the  opposite  side  of 
the  adjacent  more  distal  one,  all  arranging  themselves  thus  in  two  series  but 
actually  belonging  to  one.  In  certain  forms,  as  in  Climacograptus 
k  u  eke  r  si  an  us  [Wiman,  1888,  p.190],  one  of  the  thecae  (the  third  in  the 
species  cited)  sends  out  two  thecae,  and  thus  two  separate  series  originate 
which  are  divided  by  a  longitudinal  septum. 

In  the  Monograptidae  which  have  been  derived  from  the  Diplograptidae 
and  Climacograptidae,  only  one  of  these  series  is  developed,  but  the  thecae 
retain  their  centripetal  growth. 

While  in  the  Diplograptidae  the  tubular  thecae  have  an  oblique  position 
to  the  principal  axis  of  the  rhabdosome,  thus  producing  the  dentate  appear¬ 
ance  of  the  latter,  they  have  a  rectangular  form  in  Climacograptus  and  its 
derivatives,  and  are  appressed  in  a  position  parallel  to  the  axis,  whereby  their 
outer  margins  form  lines  parallel  to  the  axis  which  are  interrupted  by  the 
transversal  notches  of  the  apertures. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


539 


In  some  genera  of  both  series,  the  Diplograptidae  and  Climacograptidae, 
the  peridermal  walls  of  the  thecae  may  become  dissolved  into  a  system  of 
meshes.  In  the  genus  Retiograptus,  which  is,  in  the  faunas  here  described, 
represented  by  one  species,  this  dissolution  is  incomplete,  and  the  meshes 
appear  only  along  the  apertural  margins.  This  genus  appears  also  to  stand 
apart  from  the  other  Axonophora  by  the  vertical  position  of  the  thecae  on  the 
axis.  Owing  to  its  being  known  only  from  shale  material  it  is,  however,  but 
little  understood,  and  its  characters  need  further  elucidation. 

The  same  can  be  said  of  the  genus  Trigonograptus,  to  which  a  character¬ 
istic  species  of  the  zone  with  Dipl,  dentatus  has  been  referred.  The  most 
striking  and  apparently  sole  differential  character  of  this  genus  is  the  lack  of 
any  interruption  of  the  outer  margin  by  apertures.  This  is,  as  our  material 
shows  [pl.17],  produced  by  the  peculiar  position  of  the  apertures,  which  lie 
so  oblique  to  the  axis  of  the  thecae  that  they  are  subparallel  to  the  principal 
axis  of  the  rhabdosome. 

Certain  Diplograptidae  are  characterized  by  long  apertural  spines.  These 
attain  their  extreme  development  in  the  species  referred  to  Glossograptus. 

In  the  Dendroidea  and  axonolipous  Graptoloidea  only  persons  of  the  first 
order  (thecae)  and  of  the  second  order  (rhabdosomes)  have  been  observed ; 
in  some  of  the  Axonophora,  however,  (Diplograptus,  Retiograptus)  it  has 
been  found  that  the  rhabdosomes,  each  of  which  originates  from  a  sicula, 
combine  into  a  colony  which  is  thus  a  person  of  the  third  order. 

On  receptacles  for  organs  of  sexual  reproduction,  see  chapter  on  mode  of 
reproduction,  page  519. 

9  Histology  and  chemical  composition  of  the  periderm 

Richter  [1871]  "was  the  first  to  call  attention  to  the  structure  of  the 
periderm.  He  discerned  two  layers,  an  exterior,  very  flexible  one,  which  is 
again  composed  of  two  thin  lamellae,  and  a  thicker  internal  one,  which  is  pro¬ 
vided  with  transversal  ridges. 

Giimbel  treated,  a  few  years  later,  polished  specimens  with  acids  and 
came  to  a  like  conclusion  with  Richter.  He  also  inferred  that  the 


540 


NEW  YORK  STATE  MUSEUM 


periderm  had  originally  consisted  of  the  same  chitinons  substance  as  that 
of  the  sertularians. 

In  1893  Sollas  published  some  notes  on  the  peridermal  layers  of  Mono¬ 
graptus,  giving  their  dimensions. 

Perner  used  specimens  of  Monograptus  and  Retiolites  embedded  in  lime¬ 
stone  to  prepare  his  sections.  By  means  of  these  he  was  enabled  to  discern 
four  different  layers,  namely  (1)  the  epidermis  (couche  epidermique ),  which 
appears  as  a  fine,  brown  line,  (2)  the  black  layer  (couche  noire ),  a  thick,  black, 
supposedly  chitinous  band,  (3)  the  angular  layer  (couche  a  coins ),  the  thickest 
layer,  which  is  brown  and  marked  by  angular  or  zigzag  lines,  (4)  the 
columnar  layer  (couche  d  colonnettes ),  a  thin,  brown  layer,  consisting  of  small 
columns  and  possessing  a  darker  layer,  suggesting  an  internal  epidermis. 

Wiman  [1895,  p.39]  was  unable  to  discern  anything  more  than  the  black 
layers  in  sections  of  Monograptus,  made  from  Swedish  material,  but  he 
observed  the  external  epidermis  and  the  black  layer  in  sections  of  Dendro- 
graptus  and  the  external  and  internal  epidermis  and  the  black  layer  in 
sections  of  Monograptus  priodon  from  Perner’s  locality.  In  decol¬ 
orized  specimens  of  Diplograptus  he  was  also  able  to  discern  the  black 
layer  with  its  growth  lines  and  the  superjacent  epidermis  in  continuous 
patches. 

Giirich  [  1896]  has  revised  Perner’s  observations  on  the  periderm  of 
Monograptus  and  found  that  the  angular  layer  ( couche  d  coins )  consists  of 
calcite  crystals  and  is  secondarily  formed  during  fossilization ;  and  that  the 
brown  layers  observable  outside  and  inside  of  the  black  layer  are  zones  of 
pigment  which  either  are  derived  from  the  black  layer  or  formed  a  superficial 
layer  of  the  same.  The  epidermis  and  columnar  layers  have  not  been 
observed  by  Gurich. 

A  layer  of  graptolite  bed  2  (Tetragraptus  zone)  at  the  Deep  kill,  in 
which  the  graptolites  are  retained  uncompressed  in  pyrite,  provided  the 
present  writer  with  material  for  thin  sections,  principally  specimens  of 
Phyllograptus  ilicifolius  and  branching  dichograptids.  In  these 
the  walls  consist  uniformly  of  three  layers,  viz  the  black  layer,  the  angular 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


541 


layer  and  the  columnar  layer  [ see  fig.  13,  14].  The  last  two  are  distinctly 
composed  of  calcite  crystals.  As  these  two  zones  are  correlatives  in  their 
width  —  the  one  is  in  some  places  entirely  replaced  by  the  other  —  and 
as  they  are  separated  by  a  jagged  line,  corresponding  to  the  sections  of  crys¬ 
tals,  it  is  to  be  inferred  that  they  result  from  a  single  deposit  of  fibrous 
calcite  crystals,  which,  being  slightly  curved,  show  in  the  angular  zone 
their  sections  and  in  the  columnar  zone  their  lateral  faces.  Bands  of 
brown  pigment  appear  at  irregular  intervals  in  the  angular  zone.  No  traces 


Fig.  14 

Fig.  13, 14  Die  hog  rapt  us  sp.  Thin  sections  through  walls  of  pyritized 
specimens.  Deep  kill.  x215 


of  an  exterior  or  interior  epidermis  have  been  observed  in  any  of  the  sections, 
but  it  is  quite  possible  that  these,  if  present,  are,  on  account  of  their  thinness, 
entirely  concealed  by  the  pyrite  matrix. 

It  can  be  considered  however  as  established  by  Perner’s  and  Wiman’s 
observations  that  there  existed  an  “  epidermis  ”  besides  the  principal  black 
wall.  In  other  forms,  as  in  numerous  species  of  Lasiograptus,  which  the 
writer  has  collected  in  the  Trenton  graptolite  beds,  and  which  will  be 
described  in  the  next  memoir,  the  thm  epidermal  layer  and  the  principal  one, 
which  there  is  dissolved  into  a  network  of  fibers,  can  be  readily  discerned. 

The  angular  and  columnar  layers  can  not  be  considered  layers  of  the 
periderm  of  the  graptolites,  though  they  may  correspond  to  some  part  of 


542 


NEW  YORK  STATE  MUSEUM 


tire  living  animal,  no  longer  determinable,  as  is  pointed  out  by  Freeh  [loc.  cit. 
p.551].  In  reference  to  this  last  suggestion,  it  is  however  to  be  remembered 
that  the  calcite  layer,  though  of  remarkably  uniform  thickness,  is  not  always 
found  on  the  same  side  of  the  carbonaceous  periderm  and,  though  mainly 
developed  on  the  inside,  may  also  occur  on  the  outside  or  even  on  both  sides 
[see  fig.14] ;  and  that,  further,  the  calcite  band  is  often  directly  continuous 
with  the  numerous  small  calcite  veins  transecting  the  pyrite.  The  latter  fact 
would  suggest  that  the  calcite  band  may  have  been  formed  after  the  harden¬ 
ing  of  the  organic  material  which  caused  the  deposition  of  the  pyrite.  That 
the  latter  filled  the  rhabdosomes  at  a  very  early  stage  of  the  fossilization,  is 
attested  by  the  failure  of  these  rhabdosomes  to  become  compressed.  On  the 
whole,  the  calcite  bands  in  the  Deep  kill  material  appear  to  have  filled  the 
interspaces  between  the  periderm  and  the  organic  or  pyrite  matrix,  arising 
from  a  shrinkage  of  the  latter. 

The  presence  of  an  epidermic  layer  which,  according  to  Wiman’s  observa¬ 
tions,  appears  to  have  had  its  independent  system  of  growth  lines,  seems 
important  in  so  far  as  it  would  indicate  that  the  periderm  was  not  an  external 
skeleton,  but  was  formed  in  the  mesoderm.  The  latter  conclusion  has  urged 
itself  on  the  writer  ever  since  he  studied  the  colonies  of  Diplograptus,  by 
various  arguments,  the  most  important  of  which  are  the  following : 

1  The  nema  or  nemacaulus  of  Diplograptus  p  r  i  s  t  i  s  Hall  (foli- 
a  c  e  o  u  s  Murchison)  shows  from  the  sicula  onward  to  the  perfection  of 
the  first  or  primary  rhabdosome  [see  Ruedemann,  1895;  pl.3,  fig.8-14]  a  con. 
tinuous  growth  in  length  and  thickness,  which  in  a  horny,  nonporous  body 
can  be  explained  only  by  the  action  of  an  external  tissue.  The  secondary 
growth  of  the  nema  is  also  specially  remarkable  in  Tetragraptus 
fruticosus  [pi.  10,  fig.7]. 

2  The  stems  of  the  larger  multiramous  dichograptids,  as  notably 
Goniograptus  [pi.  6],  which  consist  of  thecae,  continue  to  grow  in  thickness 
till  almost  all  traces  of  their  thecal  structure  have  disappeared. 

3  Certain  species  of  dichograptids  develop  a  secondary  disk  at  the  basis 
of  the  rhabdosome  [see  Dichograptus  octobrachiatus,  pl.8,  fig.4J. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


543 


This  disk  is  not  present  in  young  individuals  and  continues  later  on  to  grow 
in  correspondence  to  the  size  of  the  whole  colony.  Its  formation  presupposes 
an  enveloping  tissue. 

4  There  appear  secondary  spines  and  other  appendages,  mostly  at  the 
distal  end,  as  in  Climacograptus  bicornis,  which,  lying  outside  of 
the  thecae,  attain  a  greater  size  and  development  than  the  individuals 
supposed  to  have  lived  in  the  small  thecae,  could  have  given  them  by  their 
action. 

5  There  is  found  in  some  forms,  as  in  Lasiograptus,  an  external  frame¬ 
work  consisting  of  horny  filaments,  which  would  suggest  that  it  served  to 
protect  this  soft  covering  tissue. 

Finally  we  mention,  that  it  has  been  claimed  by  Giimbel  that  the  periderm 
consisted  originally  of  chitin,  though  tests  recorded  by  Wiman  showed  that 
no  reaction,  characteristic  of  chitin,  is  any  longer  obtainable  from  the  fossils ; 
that  it  can  not  be  doubted  that  it  once  consisted  of  some  chitinlike  substance ; 
and,  further,  that  the  periderm  possessed  a  certain  degree  of  elastic  flexibility, 
for  the  nemas  and  rhabdosomes  are  frequently  found  bent  and  twisted  with¬ 
out  having  been  broken. 

10  Classification  and  phytogeny  of  the  graptolites 

a  Review  of  classifications.  As  the  systematic  arrangement  of  the 
organisms  is  to  express  their  true  relationship,  it  is  evident  that  no  arrange¬ 
ment  can  find  general  acceptance  so  long  as  the  investigations  on  the  morpho¬ 
logic  and  phylogenetic  relations  of  a  group  of  forms  have  not  passed  beyond 
their  inceptive  stages.  This  fact  impresses  itself  at  once  on  the  paleontologist 
wTho  attempts  to  find  a  generally  adopted  system  for  the  classification  of  a 
graptolite  fauna  under  investigation  ;  for  he  will  soon  observe  that  not  only 
the  larger  divisions  which  suggested  themselves  so  readily,  but  also  many  of 
the  genera  Avhich  once  appeared  so  well  defined  and  compact,  have  lately  lost 
and  are  still  losing  in  value  as  natural  groups. 

It  was  natural  that  a  grouping  of  the  graptolites  began  with  a  separa¬ 
tion  from  the  graptolites  proper  of  the  arborescent  forms  grouping  them- 


:>44 


NEW  YORK  STATE  MUSEUM 


selves  around  Dendrograptus  and  Dictyonema,  which  previously  were  only 
with  some  doubt  united  with  the  graptolites ;  and,  further,  that  among  the 
latter  the  forms  with  one  series  of  thecae  were  opposed  to  those  with  two 
or  more  series  of  thecae.  The  arborescent  forms  were  separated  as  Cladophora 
(Hopkinson) —  now  currently  designated  Dendroidea  (Nicholson) — from  the 
Rhabdophora,  a  term  proposed  by  Allman  under  the  wrong  supposition 
that  all  graptolites  proper  had  a  strengthening  rod,  the  virgula. 

The  number  of  series  of  thecae  was  first  used  systematically  for  the 
erection  of  several  divisions  by  Hopkinson,  who  proposed  the  groups  Mono- 
prionidae ,  Mono-Diprionidae ,  Diprionidae  and  Tetraprionidoe.  Hopkinson’s 
suggestions  have  been  further  elaborated  in  Lapworth’s  complete  system 
(1873).  In  this  the  Rhabdophora  are  divided  into  two  sections,  viz  (1) 
Graptolitidae  and  (2)  Retioloidea.  The  Graptolitidae  are  characterized  as 
developing  the  rhabdosome  from  a  true  sicula ;  having  a  coenosarc,  from  which 
originates  a  single  series  of  thecae  only  (the  Diprionidae  included  in  this 
section  were  considered  by  Hall  and  others  as  possessing  a  “dibrachiate 
monoprionidian  polypary,  whose  branches  coalesce  by  the  whole  of  their 
dorsal  surfaces”)  and  as  having  a  dorsal  virgula  embedded  in  a  narrow 
groove  on  the  exterior  surface  of  the  periderm.  The  Retioloidea,  on  the 
other  hand,  were  stated  to  have  their  rhabdosome  never  developed  from  a 
siculiform  “  germ,”  as  having  a  coenosarc  originating  a  double  series  of  thecae, 
and  as  possessing  an  epiderm  which  is  more  or  less  supported  by  a  framework 
of  chitinous  filaments. 

The  first  section  was  further  divided  into  (1)  Monoprionidae ,  compris¬ 
ing  the  families  Monograptidae,  Nemagraptidae  (Leptograptus,  Amphigraptus, 
Pleurograptus,  Nemagraptus,  Coenograptus),  Dicliograptidae  (Didymograptus, 
Tetragraptus,  Dichograptus,  Loganograptus,  Clonograptus  and  four  unnamed 
genera,  represented  respectively  by  Gr.  multifasciatus,  milesi, 
vagans  and  richardsoni);  (2)  the  Mono-Diprionidae ,  comprising  the 
family  Dicranograptidae ,  with  the  genera  Dicellograptus  and  Dicranograptus ; 
(3)  the  Diprionidae ,  comprising  the  family  Diplograptidae  (genera  Climaco- 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


545 


graptus  and  Diplograptus)  ;  (4)  the  Tetraprionidae  with  the  Phyllograptidae 
and  the  single  genus  Phyllograptus. 

The  Retioloidea  were  divided  into  the  Glossog rap tidae  (a  provisional 
family  with  the  genera  Glossograptus,  Retiograptus  and  Lasiograptus)  and 
the  Retiolitidae  with  the  genera  Clathrograptus,  an  unnamed  genus  for 
Retiograptus  eu  char  is  Hall,  Trigonograptus  and  Retiolites, 

This  classification,  which  was  supported  by  concise  and  clear  generic 
definitions,  given  in  an  analytic  table,  has  been  generally  adopted  and  has,  as 
far  as  the  grouping  of  the  genera  into  families  is  concerned,  thus  far  well 
stood  the  test  of  later  investigations,  so  that,  on  the  whole,  the  families 
appear  to  represent  natural  divisions.  Lapworth  himself  claimed  already  for 
the  families  of  the  Monoprionidae  that  they  represent  natural  divisions,  seeing 
a  confirmation  of  his  claim  in  “  the  known  geological  distribution  of  the 
genera  constituting  the  several  families.” 

The  investigations  of  Swedish  paleontologists,  on  uncompressed  material, 
have  however  demonstrated  that  some  of  the  larger  divisions  contain  heter¬ 
ogeneous  material  and  that  the  forms  constituting  others  are  not  entitled  to 
comprise  a  group  of  higher  rank.  The  Monoprionidae  contain  at  least  two 
widely  different  groups,  viz  the  Monograptidae  and  the  Dichograptidae.  The 
former,  which  are  among  the  last  appearing  Graptolitidae,  have  in  their 
rhabdosomes  proximally  or  inwardly  directed  thecae  and  a  virgula,  and 
are  derivatives  of  the  Diplograptidae ;  while  the  Dichograptidae,  which  con¬ 
tain  some  of  the  earliest  genera,  as  Clonograptus,  have  distally  directed  thecae 
and  lack  a  supporting  rod  within  the  branches.  The  division  Monoprionidae 
is  hence  best  discarded  and  has  in  fact  not  been  used  in  the  latest  systematic 
arrangements,  as  those  of  Wiman  and  Freeh. 

The  suborder  Diprionidae  has  likewise  become  untenable  on  account  of 
the  fact  that  the  rhabdosomes  of  the  Diplograptidae  are  monoprion idian  in 
origin,  i.  e.  originate  from  one  theca,  the  consequent  close  relationship  with 
the  Monograptidae,  and  the  further  fact  that  the  Retioloidea  contain  forms 
with  a  like  arrangement  and  origin  of  the  thecae. 


546 


NEW  YORK  STATE  MUSEUM 


The  Tetraprionidae  (Phyllograptus)  have  been  shown  to  be  only  an 
aberrant  branch  of  the  Dichograptidae  in  which  the  four  recumbent  branches 
coalesce. 

Wiman  has,  in  his  paper  “  Ueber  die  Graptoliten  ”  [p.25ff]  applied  the 
results  of  his  researches  to  an  improvement  of  Lap  worth’s  system  He 
divides  the  graptolites  into  three  groups,  viz  Graptoloidea  Lapworth, 
JRetioloidea  Lapworth  and  Dendroidea  Nicholson.  Under  these  are  arranged 
the  families  and  genera,  which  are  largely  taken  from  Lapworth’s  “  Improved 
Classification  of  the  Rhabdophora.”  In  this  way  he  has  placed  later  erected 
genera  in  their  respective  places,  adding  however,  that  in  his  belief  many 
of  them,  notably  among  the  Dichograptidae,  are  not  deserving  of  generic 
rank. 

A  greatly  differing  system  has  been  proposed  by  Freeh  [1897,  p.568ffj. 
This  author  has,  in  recognition  of  the  important  fact,  that  all  the  later 
graptolites  have  a  virgula  incorporated  into  the  rhabdosomes  and  bear  the 
sicula  at  the  distal  end  of  the  rhabdosomes,  divided  all  graptolites  into  two 
orders,  viz  the  Axonolipa ,  or  forms  without  an  axis,  and  the  Axonophora ,  or 
forms  -with  an  axis.  The  Axonolipa  contain  the  families  Dendrograptidi 
(Dictyonema,  Dendrograptus  etc.)  and  Dichograptidi  (including  Dicho¬ 
graptidae  Lapw.,  Leptograptidae  Lapw.,  Didymograptidae  auct.  and  Phyllo- 
graptidae  Lapw.).  The  latter  are  again  divided  into  the  subfamilies 
Didymograptini,  Tetragraptini  and  Phyllograptini.  The  Axonophora  are 
subdivided  into  the  families  Climacograptidi,  Diplogvaptidi,  Monograptidi 
and  Retiolitidi.  The  Climacograptidi,  hitherto  united  with  the  Diplo- 
graptidi,  are  separated  on  account  of  the  rectangular  fixation  of  the  thecae 
and  the  location  of  the  apertures.  This  family  comprises  the  genera  Retio- 
graptus,  Climacograptus,  Dicranograptus,  Dicellograptus  and  Monoclimacis. 
It  will  be  noticed  that  Freeh  unites  here,  by  the  direction  and  shape  of  the 
thecae,  forms  of  very  different  appearance,  as  the  biserial  Climacograptus  and 
uniserial  Monoclimacis  and  transfers  the  genus  Retiograptus,  hitherto  united 
with  the  Retioloidea,  but  in  which  the  latticed  sculpture  of  the  periderm  is 
still  little  developed,  to  the  Climacograptidi.  The  family  Diplograptidi  has 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


547 


been  made  the  receptacle  of  the  genera  Diplograptus,  Glossograptus  and 
Dimorphograptus.  The  family  Monograptidi  has  the  same  compass  as  is 
given  to  it  by  Lapwortli.  The  Retiolitidae  comprise  the  genera  Retiolites, 
Gothograptus,  Lasiograptus  and  Clathrograptus. 

We  have  here  adopted  with  some  modification  [p.570]  Freeh’s  terms 
Axonolipa  and  Axonophora,  for  the  reason  that  they  appear  to  give  proper 
significance  to  important  differences  in  the  structure  of  the  rhabdosomes. 
In  the  former  the  nema  remains  free  and  the  thecae  are  directed  distally ;  in 
the  latter  the  virgula  and  nema  become  the  axis  of  the  rhabdosome  and  the 
thecae  are  directed  proximally  or  centrally ;  in  the  former  only  single 
rhabdosomes  have  been  observed,  while  in  the  latter,  as  far  as  complete 
material  has  been  found,  the  rhabdosomes  were  united  into  synrhabdosomes, 
and  thus  a  higher  and  more  complicated  form  of  colony  attained.  As  the 
two  orders  are  also  separated  in  time,  the  Axonophora  replacing  the 
Axonolipa  from  the  middle  of  the  Lower  Siluric  formation  onward,  it  can 
hardly  be  doubted  that  we  have  ■  to  see  in  these  orders  natural  divisions 
of  great  import. 

The  fact  that  the  Phyllograptidae  among  the  Dichograptidae  approach 
by  the  coalescence  of  their  recumbent  branches  the  Diplograptidae  in 
external  appearance,  and  that,  also,  the  nema  appears  to  become  incorpor¬ 
ated  [see  Phyllograptus  anna  mut.  pygmaeus,  p.716]  into  the  rhab¬ 
dosome  as  an  axis,  thus  making  this  form  axonophorous  to  some,  extent,  is 
liable  to  lead  to  the  misconception  that  this  family  contains  forms  with 
some  of  the  distinctive  characters  of  the  Axonophora;  but  the  four  series 
of  thecae  in  Phyllograptus  represent  separate  coalescent  branches,  while 
in  Diplograptus  the  two  series  are  produced  by  the  alternate  arrangement 
of  the  thecae  of  but  one  series.  The  axis  of  the  Diplograptidae  is  the 
virgula  which  is  already  formed  in  the  wall  of  the  sicula,  while  that  of 
Phyllograptus  anna  mut.  p  y  g  m  a  e  a  is  only  the  nema  or  support¬ 
ing  thread  of  the  sicula.  The  axis  of  the  Diplograptidae  is  hence  a  new 
acquisition  not  found  in  the  Dichograptidae.  In  some  Phyllograptidae,  more¬ 
over,  this  thread  has  been  lost  or  is,  as  Holm’s  observations  on  Phyllo- 


548 


NEW  YORK  STATE  MUSEUM 


g  r  a  p  t  u  s  a  n  g  u  s  t  i  f  o  1  i  u  s  indicate,  no  longer  distinguishable  within  the 
coalesced  dorsal  walls  of  the  branches. 

b  Phylogeny  of  the  orders  of  graptolites.  A  problem  not  yet  solved  is 
the  relation  of  the  Dendroidea  to  the  Graptoloidea.  Freeh  considers  the 
Dendrograptidi  a  part  of  the  Axonolipa.  In  fact,  they  lack  the  support¬ 
ing  rod  of  the  Axonophora,  and  their  thecae  are  directed  distally,  while 
the  sicula  holds  a  proximal  position.  But  they  differ  so  greatly,  not  only 
in  general  appearance  of  the  mature  colonies,  but  also  in  the  composition 
of  the  branches,  from  all  other  graptolites,  that  the  question  is  pertinent, 
whether  they  should  not  be  considered  a  separate  order  for  themselves, 
specially  as  they  also  continue  to  coexist  with,  or  rather  persist  beyond,  all 
other  graptolites. 

It  is  here,  however,  not  to  be  forgotten  that  several  authors  have 
recently  been  not  disinclined  to  consider  the  Graptoloidea  as  derived  from  the 
Dendroidea.  Thus  Wiman  [1893,  p.35]  has  pointed  out  that  a  fragment  of  a 
dendroid  is  often  externally  undistinguishable  from  a  fragment  of  a  grap- 
toloid,  and  suggested  that  the  rhabdosomes  of  Graptoloidea  may  be  but 
the  external  periderm  of  those  of  Dendroidea,  and  that  in  the  former  the 
delicate  tubes  (his  “  gonangia  ”  and  “  budding  individuals ,:)  filling  the  com¬ 
mon  canal  of  the  Dendroidea,  Avhich  also  in  these  are  rarely  retained, 
may  have  been  so  thin  Availed  that  they  never,,  or  only  in  most  excep¬ 
tional  cases,  left  any  traces  of  their  former  existence.  He  adduces  in  this 
connection  an  observation  of  Hopkinson  [1882,  p.56j,  Avbo  observed  in 
Tetragraptus  s e r r a  and  Didymograptus  extensu s,  partitions 
between  the  proximal  parts  of  the  thecae  and  the  common  canal,  which  sepa¬ 
rate  the  latter  by  transverse  septa  into  spaces  corresponding  to  the  thecae.  No 
traces  of  these  partition  walls  have  been  found  by  the  writer  in  sections  of 
pyritized  specimens  of  several  Dichograptidae,  and  it  seems  possible  that  the 
appearance  of  the  partitions  has  been  produced  by  cutting  through  the 
proximal  parts  of  the  thecae  in  someAvhat  obliquely  embedded  material. 
HoAvever  this  may  be,  it  is  to  be  conceded  that  the  failure  to  observe  the 
delicate  tubes  AArithin  the  Graptoloidea,  with  the  restricted  number  of  observa- 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


549 


tions  of  the  internal  structure  of  Graptoloidea,  can  not  be  considered  as 
constituting  a  fundamental  difference  between  the  two  orders. 

Elies  [1898,  p.536]  also  places,  in  a  table  giving  the  “suggested  phy- 
logeny  of  a  part  of  the  Skiddaw  slate  graptolites,”  Dictyonema  at  the  base  of 
the  system  leading  through  Bryograptus  to  Tetragraptus  and  Didymograptus. 

If  we  add  that  the  sudden  appearance  of  the  progenitors  of  the  Dicho- 
graptidae,  the  genera  Bryograptus  and  Clonograptus,  in  the  wake  of  the 
equally  sudden  and  widespread  appearance  of  Dictyonema  flabelli- 
forrne  may  be  due,  as  Lapworth  has  suggested,  to  the  change  of  these 
forms  from  a  sessile  benthonic  mode  of  life  to  a  planktonic  or  pseudoplank- 
tonic  one,  the  conclusion  appears  legitimate  that  the  Dendroidea  precede  the 
Graptoloidea  in  time,  and  that  the  possible  transitional  forms  between  the 
two  orders,  being  still  benthonic,  are  not  readily  accessible  to  observation ; 
that,  hence,  the  failure  to  observe  them  is  no  argument  against  their  former 
existence. 

It  may  be  further  stated  that  the  possession  of  like  initial  receptacles, 
the  siculae,  and  the  similarity  of  the  early  parts  of  the  rhabdosomes  in 
Dictyonema  flabelliforme  and  Staurograptus  [pi. 2]  can  also  be 
regarded  as  suggesting  common  ancestors  for  these,  and  a  consequent  closer 
relationship,  as  the  mature  colonies  would  indicate. 

As  an  alternative  theory,  the  possibility  of  a  derivation  of  the  Den* 
•  droidea  from  the  Graptoloidea  has  been  pointed  out  by  Wiman ;  this 
phylogenetic  relation  being  considered  by  that  author  the  more  probable  on 
the  ground  that  differentiation  of  individuals  frequently  is  produced  by  a 
division  of  labor.  This  theory,  it  is  thought,  might  also  explain  the  fact  that 
the  proximal  thecae  of  Dictyonema  peltatum  are  similar  to  those  of 
Graptoloidea. 

The  solution  to  the  entire  problem  of  the  relations  between  Dendroidea 
and  Graptoloidea  rests  obviously  with  the  discovery  of  earlier  Cambric 
graptolites,  and  specially  with  that  of  the  structure  of  the  reproductive 
individuals  in  the  Dichograptidae. 


550 


NEW  YORK  STATE  MUSEUM 


The  connection  between  the  Axonolipa  and  Axonophora  is  still  obscure. 
The  fact  is  that,  where  in  the  Lower  Siluric  the  axonophorous  genera 
appear  —  in  the  Mt  Moreno  beds  and  the  Deep  kill  section  in  the  zone  with 
Dip  log  rapt  us  dentatus,  with  the  genera  Diplograptus,  Climacograp- 
tus,  Glossograptus,  Trigonograptus  and  Retiolites  —  they  at  once  come  on  the 
field  in  great  force,  and  that  the  Axonolipa  then  rapidly  disappear.  Further, 
no  form  is  known  in  the  preceding  zones  which  could  be  conclusively  held  to 
announce  or  foreshadow  this  new  departure  in  graptolitic  structure.  We 
have  here,  hence,  apparently  an  interesting  illustration  of  the  principle  empha¬ 
sized  by  Hyatt :  that  types  are  evolved  more  quickly  near  the  point  of  origin, 
and  that  there  are  greater  structural  differences  between  genetic  groups  of  the 
same  stock  while  still  near  this  point  than  appear  subsequently. 

The  genera  Diplograptus,  Climacograptus,  Trigonograptus  and  Retiolites, 
appearing  suddenly  side  by  side,  encompass  already  the  full  amplitude  of  the 
structural  differences  as  expressed  in  the  position  of  the  thecae  found  among 
the  diprionid  Axonophora ;  while  Retiolites  already  indicates  the  perforation 
of  the  peridermal  wall,  that  becomes  fully  developed  in  later  phases,  and 
Glossograptus  already  presents  the  extreme  growth  of  spinous  appendages  in 
this  class  of  graptolites. 

It  is  known  that  a  strong  tendency  to  the  perfection  of  the  structure 
attained  by  the  Diplograptidae  and  which  insures  a  stable  upward  growth  of 
the  thecae,  has  manifested  itself  distinctly  in  the  preceding  Dichograptidae 
by  the  assumption  of  a  reclined  position-  of  the  branches  and  led  to  the 
development  of  such  forms  as  the  Phyllograptidae,  the  reclined  Tetragrap- 
tidae  (Tet  rag  rapt  us  similis)  and  Didymograptidae,  as  D  i  d  y  m  o  - 
graptus  caduceus  (gi b  b  e r  u  1  u  s).  It  would  hence  seem  proper  to 
look  among  these  reclined  forms  for  the  ancestors  of  the  Diplograptidae. 

An  interesting  observation,  probably  suggestive  of  the  path  of  derivation 
of  Diplograptus  from  the  Dichograptidae,  has  been  recorded  by  Tornquist 
[1901,  p.23]  and  verified  by  Elies  and  Wood  [1901,  p.53].  The  latter 
authors  state  of  Didymograptus  gibber  ulus:  “The  crossing  canal 
is  clearly  seen  just  below  the  apex  of  the  sicula,  and  rather  above  the  initial 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


551 


parts  of  tlie  thecae  which  have  developed  later.  There  appears  also  to  be  a 
crossing  canal  (or  something  of  a  similar  nature)  between  th.  21  and  th.  I2. 
Thus,  as  Tornquist  points  out  \loc.  cit.\  ‘The  first  stipe  crosses  the  sicula 
and  the  second  stipe  the  first  theca.’  This  seems  to  show  that  in  this  species 
there  is  a  deviation  from  the  normal  Didymograptus  type  of  development, 
that  is  to  say,  a  forecast  of  the  type  characteristic  of  the  Diplograptidae.” 

If,  indeed,  the  budding  of  thecae  on  alternate  sides,  which  produces  the 
double  intertwined  series  of  thecae  in  Diplograptus,  originated  with  the  first 
thecae  of  a  Didymograptus  with  reclined  branches,  such  as  D.  gibber  ulus, 
the  acceleration  of  the  development  of  the  ancestral  characters  must  have 
been  extremely  rapid,  for  the  only  vestige  left  of  the  former  downward 
direction  of  the  first  thecae  of  the  ancestral  Dichograptidae  is  the  short, 
initial,  downward  course  of  the  first  theca  in  Diplograptus  and  Climaco- 
graptus  [text  fig.10].  This  and  the  downward  direction  of  the  sicula  seem 
indeed  to  be  the  only  facts  of  ontogenetic  importance  for  a  phylogenetic 
linking  of  the  Axonophora  with  preceding  graptolites.  The  fact  of  the 
replacement  in  time  of  the  Dichograptidae  by  the  Axonophora  would  seem  to 
lend  support  to  the  assumption  of  this  phylogenetic  connection  of  the  two 
orders  of  graptolites. 

On  the  other  hand,  it  should  not  be  forgotten  that  the  siculate  rhabdo- 
somes  of  the  Axonophora  unite  into  individuals  of  a  higher  order,  the 
synrhabdosomes  of  Diplograptus  and  Retiolites,  and  thus  an  additional 
distinctive  character  is  found  in  the  Axonophora  no  indication  of  which 
is  as  yet  known  among  the  Dichograptidae. 

The  incorporation  of  the  nemacaulus  in  the  rhabdosome  of  the  Diplo¬ 
graptidae  as  support  of  the  backward  or  upward  growing  thecae,  which,  so  to 
say,  climb  upward  along  the  nemacaulus,  has  induced  the  formation  of  a 
special  organ  among  the  Axonophora,  the  virgula,  which  is  found  to  originate 
within  the  wall  of  the  sicula  of  these  forms,  as  far  as  they  have  been  studied. 
This  appears,  then,  to  be  an  interesting  case  of  the  transference  by 
tachygenesis  of  a  character,  the  virgula,  newly  acquired  by  a  colony,  to 
the  embryonic  stage  (sicula)  of  the  whole  colony.  The  appearance  of 


NEW  YORK  STATE  MUSEUM 


this  coenoorenetic  character  in  the  sicula  is  also  evidence  of  the  extreme 
rapidity  of  development  among  the  graptolites,  evinced  already  by  the  rapid 
changing  of  the  faunas  in  the  successive  beds. 

It  is,  however,  in  my  opinion,  doubtful  whether  the  solid  axis  or  virgula 
of  the  Axonophora  is  a  homologous  organ  in  the  different  groups  of  that 
order.  It  seems  almost  impossible  that  the  virgula  of  Diplograptus,  which 
originates  in  the  sicula  and  nemacaulus,  and  with  the  latter  becomes  incorpo¬ 
rated  in  the  rhabdosome,  should  be  homologous  to  the  bipartite  axis  found 
within  the  two  reclined  branches  of  Dicellograptus ;  for  the  nema  from  which 
the  sicula  of  the  latter  was  originally  suspended,  is,  according  to  my  observa¬ 
tion  and  knowledge,  never  incorporated  in  either  of  the  branches.  The  axes 
of  Dicellograptus  appear  to  be,  for  this  reason,  only  thickenings  of  the 
dorsal  wall  of  the  coenosarcal  canal,  induced  by  the  upward  growth  of  the 
branches,  while  the  virgula  of  the  typical  Axonophora  is  a  separate  rod.  Such 
secondary  strengthening  of  the  branches  is  described  in  this  memoir  even 
from  a  dichograptid,  viz  Tetragraptus  a m i i  [p.647  and  pl-.l  1 J. 

The  early  appearance  of  a  Dicellograptus,  viz  D .  moffatensis,  in 
the  zone  with  Diplograptus  dentatus  of  the  Upper  Skiddaw  slates, 
is  very  suggestive  of  the  derivation  of  that  genus,  not  from  the  later  Dicrano- 
graptus,  as  generally  supposed,  but  from  Didymograptus.  From  the  latter  it 
is  only  separated  by  the  presence  of  the  solid  virgula  and  the  peculiar  shape 
of  the  thecae.  Both  are  probably  secondary  acquisitions,  and  the  form, 
described  here  as  Didymograptus  incertus,  appears  to  me  to  indi¬ 
cate  the  path  of  this  derivation ;  for,  though  it  is  in  all  its  appearance  and 
by  the  presence  of  the  dorsal  thickening  a  Dicellograptus,  it  has  the  thecae  of 
a  Didymograptus.  As  the  peculiar  thecal  shapes  of  the  Upper  Champlainic 
and  Upper  Siluric  species  are  distinctly  later  acquisitions,  appearing  only 
toward  the  end  of  the  graptolite  reign,  they  are  here  of  no  phylogenetic 
significance. 

If  then  the  virgula  of  Diplograptus  is  an  organ  originating  within  the 
sicula  and  nemacaulus,  and  that  of  Dicellograptus  an  organ  which  originates 
within  the  walls  of  the  coenosarcal  canal  of  the  branches,  they  can  not  be 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


553 


homologous  organs,  though  the  mode  of  the  formation  of  the  virgula  within 
the  walls  of  the  sicula  of  Diplograptus  suggests  that  this  virgula  also  was 
originally  but  a  thickening  of  the  periderm  —  of  the  nemacaulus  however  — 
and  only  afterward  became  more  or  less  separated  as  a  rod. 

Since  it  is  obvious  that  our  stock  of  observed  facts  is  not  yet  sufficient  to 
solve  either  the  problem  of  the  relationship  of  the  tw'o  largest  divisions  of 
graptolites,  the  orders  Axonolipa  and  Axonophora,  or  that  of  the  phylogenetic 
connection  between  the  two  large  groups  of  graptolites  which  Freeh  has 
united  under  the  caption  Axonolipa,  viz  the  Dendrograptidae  and  Dicho- 
graptidae,  it  appears  that  the  present  status  of  our  knowledge  of  the 
differences  between  the  Dendrograptidae,  Dichograptidae  and  Axonophora 
would  be  best  expressed  by  still  recognizing  all  of  them  as  independent 
orders. 

c  Phylogeny  of  the  genera  and  species.  Speculation  as  to  the  possible 

phylogenetic  relations  of  the  genera  of  the  Dendroidea ,  Dictyonema,  Desmo- 
graptus,  Dendrograptus,  Callograptus  and  Ptilograptus  would  be  altogether 
premature,  since  these  groups  are  based  thus  far  largely  on  external  char¬ 
acters  which,  in  view  of  the  complicated  internal  structure  observed  in 
several  species,  are  probably  inadequate  to  a  correct  understanding  of  their 
natural  relations. 

The  problem  of  the  phytogeny  of  the  Dichograptidae  has  been  the 
subject  of  investigation  by  Nicholson  and  Marr,  whose  work  has  been  ably 
continued  by  Elies. 

Nicholson  and  Marr  [1895,  p.529]  observed  that  in  the  more  ancient 
types  of  graptolites  the  thecae  are  comparatively  simple,  while  in  the  later 
types,  as  Dicellograptus,  Dicranograptus  and  Monograptus,  they  are  much 
more  complex.  A  number  of  groups  can  be  discerned  by  the  character  of  the 
thecae.  From  these  facts  they  concluded  “  that  the  character  of  the  thecae 
is  the  most  important  point  to  retain  in  separating  families  of  the  Grapto- 
loidea,”  and  that  the  next  most  important  point  to  consider  as  indicating 
genetic  relationship  is  the  “  angle  of  divergence,”  tvhile,  on  the  other  hand, 
the  number  of  branches  in  the  rhabdosome,  by  which  our  present  genera 


554 


NEW  YORK  STATE  MUSEUM 


of  the  Dichograptidae,  as  Tetragraptus,  Didymograptus,  Loganograptus, 
Dichograptus,  are  largely  defined,  is  a  character  of  minor  importance. 

They  find  that,  when  the  Dichograptidae  are  separated  into  groups 
characterized  by  their  thecae,  (1)  the  different  groups  exhibit  a  series  of 
parallel  modifications  as  regards  the  number  of  branches  in  the  rhabdosome, 
and  (2)  the  older  forms  of  the  group  are  more  complex,  and  the  later  forms 
undergo  reduction  in  the  number  of  branches. 

To  illustrate  this  important  principle,  the  authors  show  that,  of  the  nine 
species  of  Tetragraptus  well  known  to  them,  “  eight  are  represented  by  forms 
of  Didymograptus  which  are  closely  comparable  as  regards  the  characters  of 
the  liydrothecae.”  It  is  further  stated,  that  four  of  these  four  branched 
Tetragrapti  are  represented,  as  regards  the  character  of  the  thecae  and  the 
amount  of  the  angle  of  divergence,  by  forms  of  Dichograptus  or  Bryograptus. 

The  extraordinary  resemblances  between  the  various  species  of  Bryo 
graptus,  Dichograptus,  Tetragraptus  and  Didymograptus  have  led  the  authors 
to  the  conclusion  that  the  species  of  these  genera  have  not  descended  from  a 
common  ancestral  form  for  each  genus,  but  are  the  result  of  the  variation  of 
a  number  of  different  ancestral  types  along  similar  lines.  These  lietero- 
genetic,  homoeomorphous  derivations,  as  they  are  termed  by  the  authors, 
appear  more  or  less  simultaneously,  a  fact  which  has  made  them  extremely 
valuable  to  the  geologist.  The  explanation  for  the  remarkable  parallelism 
displayed  in  the  reduction  of  multiramous,  irregularly  branching  forms 
through  multiramous  regularly  branching  to  pauciramous  symmetric  forms, 
among  the  Dichograptidae,  is  sought  in  the  suggestion  that  symmetry 
in  the  arrangement  of  the  branches  would  tend  to  insure  an  equal  supply 
of  food  to  each  branch,  and  that  the  fewer  the  branches  the  greater  the 
supply  of  food  to  the  entire  organism. 

The  suggestions  of  Nicholson  and  Marr  on  the  phylogeny  of  the 
Dichograptidae  have  been  made  the  subject  of  a  most  detailed  investigation 
by  Elies  [1898,  p.529ff].  This  authoress,  who  states  that  in  her  study  of  the 
Skiddaw  slate  graptolites  she  has  also  been  greatly  impressed  by  the 
remarkable  resemblances  between  species  of  different  genera,  has  obtained 


SUGGESTED  PHYLOGENY  OF  THE  AMERICAN  GRAPTOLOIDEA  AXONOLIPA 


Didymograptu s  stage  „ 


Tetragraptus  stage  .  . 


Multiramous  stage .  . 


Coenograptus  gracilis 


Didyinograptus  forcipifer 


Did.  nanns 


Didymograptus  cadueens 


Did.  bifldus 


Phyllograptus  angustifolius  ( 


(Tetragraptus  phyliograptoides) 


Tet.  pygmaeus 


Did.  indentus 


Tet.  (postlethwaiti) 
Tet.  clarkei 


Tetragraptus  sirailis  Tet.  fruticosus 


Bryograptus  pusillus 


(Bryograptus  kjerulfi) 


Bryograptus 


Staurograptus  dickotomus 
var.  apertus 


Did.  cuspidatus 


Did.  ellesi 

! 


Did.  nicholsoui 


Did.  acutidens 


Tet.  pendens  Tet.  taraxacum 


Tet.  sp. 


Bryograptus  lapworthi 


Did.  similis 

I 


Did.  gracilis 


Did.  filifcrmis 


Tet.  lentns 


Sigmagraptus  praecursor 


Did.  extensus  Did.  patnlus 


Tet.  quadnbrachiatus 


Tet.  headi 


Dich.  pentad  type 

1 

Dicli.  hexad  type 

I 

Dich.  septad  type 
Dich.  octobrachiatus 


Loganograptns  logani 


Goniograptus  geometricus 


Goniograptus  perflexilis 


Clonograptus 


Did.  arcuatus 


Tet.  serra 


Tet.  amii 


Dich.  octonarius 


Temnograptus  noveboraeensis 


Clonograptus 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


555 


and  compared  the  thecal  characters,  and  the  measurements  of  the  number 
of  thecae  within  a  certain  space,  of  their  inclination,  apertural  angle  and 
overlap,  and  by  means  of  these  exact  data  confirmed  the  close  resemblance  of 
the  characters  of  the  thecae  in  members  of  different  genera. 

Miss  Elles’s  investigations  have  led  her  to  agree  with  Nicholson  and 
Marr  (1)  that  these  resemblances  are  of  gevetic  origin ,  and  therefore  (2)  of 
systematic  value  /  and  further  (3)  that  in  any  natural  group  the  forms  with 
relatively  fewer  branches  were  developed  from  the  more  complex  forms ;  so 
that  it  follows  from  this  (4)  that  the  so  called  “  genera  ”  of  the  usually 
accepted  classification  of  the  Dichograptidae  are  far  more  of  a  chronologic 
than  of  a  zoologic  significance.  Her  own  work  has  suggested  the  further 
conclusion  that  the  forms  in  question  are  most  probably  the  result  of  develop¬ 
ment  along  certain  special  lines. 

Altogether  eight  groups  with  like  thecal  characters  are  recognized  by 
Miss  Elies  among  the  Dichograptidae  of  the  Skiddaw  fauna.  Some  of  these 
groups  (five)  are  derived  from  the  early  multiramous  genus  Bryograptus,  and 
the  remaining  three  from  Clonograptus.  In  each  case  the  reduction  in  the 
powers  of  dichotomy  leads  first  to  a  Tetragraptus  and  finally  to  a  Didymo- 
graptus.  As  many  of  the  forms  are  also  represented  in  our  Deep  kill  fauna, 
we  cite  these  groups  and  invite  the  reader  to  test  the  similarity  of 
the  forms  belonging  to  the  same  groups,  as  far  as  possible  by  using  the 
plates. 

(1)  GRAPTOLITES  DERIVED  FROM  BRYOGRAPTUS 


(a)  Bryograptus  ramosus  var.  cumbrensis 
Tetragraptus  pendens 

*  Didymograptus  indentus 

( b )  Bryograptus  ramosus  var.  cumbrensis 
Tetragraptus  fruticosus 
Didymograptus  furcillatus 

( c )  Bryograptus  ramosus  var.  cumbrensis 
Tetragraptus  postlethwaitii 
Didymograptus  bifidus 

(d)  Tetragraptus  big  shy  i 


T.  phyllograptoides 
Phyllograptus  angustifolius  f 
Didymograptus  gibberulus 
(e)  Bryograptus  callavei 

Tetragraptus  sp.  (Hincksii  type) 
Didymograptus  nicholsoni 
Azygograptus  lapwortlii 
Didymograptus  affinis 
Azygograptus  suecicus 
Didymograptus  gracilis 


550 


NEW  YORK  STATE  MUSEUM 


(2)  GRAPTOLITES  DERIVED  FROM  CLONOGRAPTUS 


(f)  *  Dichograptus  octonarius 
Tetragraptus  serra 

*  Didymograptus  arcuatus 

(g)  Loganographis  logani 
Dichograptus  octobrachiatus 


Tetragraptus  quadribrachiatus 
Didymograptus  extensus 
(  h  )  *  Tetragraptus  lieadi 
Didymograptus  patulus 


These  groups  can  readily  be  arranged  into  genealogic  trees  or  diagrams, 
as  has  been  done  by  Miss  Elies,  the  first  of  these  having  Dictyonema  and  the 
others  Clonograptus  as  their  basal  form. 

The  forms  which  are  constituents  of  the  New  York  fauna  are  printed 
here  in  italics  and  those  not  reported  from  here,  but  found  in  Canada,  are 
marked  by  an  asterisk.  This  arrangement  readily  shows  that  the  ancestral 
species  of  Bryograptus  are  foreign  to  this  continent ;  but,  on  the  other  hand, 
some  forms  have  been  cited  in  the  lists  which  have  not  yet  been  found  in  the 
Skiddaw  slates.  This  would  be  expected  in  a  class  which,  like  that  of  the 
graptolites,  has  not  developed  in  a  small  restricted  area,  but  is  of  world- wide 
distribution,  and  the  complete  phylogeny  of  which  could  hence  be  obtained 
only  by  a  comprehensive  study  of  all  the  contemporaneous  forms. 

A  closer  inspection  of  the  lists  cited  above  demonstrates  that  there 
still  exist  considerable  gaps  and  differences  between  some  of  the  forms,  which, 
for  instance,  between  Bryograptus  ramosus  var.  eumbrensis  and 
Tetragraptus  fruticosus,  are  so  great  —  not  only  in  general  appear¬ 
ance  but  also  in  the  character  of  the  thecae  —  that  a  derivation  of  the  latter 
from  the  former  without  existing  intermediate  forms  is  still  hypothetic. 

On  the  whole,  however,  the  study  of  the  succession  and  morphology  of 
the  Dichograptidae  of  the  Deep  kill  fauna  not  only  has  corroborated  the  view 
of  the  British  authors  on  the  probable  phylogeny  of  these  forms,  but  has  also 
furnished  a  considerable  number  of  additional  similarities  between  different 
species  and  genera,  which  are  enumerated  here : 

(1)  The  series  leading  to  Tetragraptus  fruticosus  is  continued 
in  the  next  horizon  by  T  .  c  1  a  r  k  e  i . 

The  relation  of  these  two  species  is  discussed  under  the  latter  [p.653], 
and  it  is  stated  there  that  T.  clarkeiisa  later,  interesting  derivative  from 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


557 


T.  fruticosus,  in  which,  by  the  process  of  acceleration  in  development, 
the  flexure  and  widening  of  the  branches  have  been  transferred  to  their 
proximal  portions. 

(2)  Didymograptus  s  i  m  i  1  i  s  agrees  in  the  characters  of  its  thecae  so 
closely  with  Did.  extensus  that  it  can  safely  be  held  to  be  a  descendant 
of  that  species  which  has  fallen  below  the  size  which  the  series  attained  at  the 
time  of  its  acmic  development  in  the  Tetragraptus  horizon.  Did.  similis 
is  found  in  the  next  two  horizons,  that  with  Did.  bifid  us  and  that  with 
Diplograptus  dentatus.  It  possesses  inconspicuous  sicula,  the  broad 
and  short  thecae  of  Did.  extensus,  the  thecae  number  in  both 
9-10  within  the  space  of  10mm,  and  the  angle  of  inclination  and  overlap 
of  the  thecae  do  not  differ  materially ;  the  overlap  of  the  thecae  is  a  little 
greater  (two  thirds  to  three  fourths  against  one  half  to  two  thirds  in  Did. 
extensus),  indicating  a  slight  condensation  of  the  thecae,  while  at 
the  same  time  the  total  length  of  the  branches  has  become  greatly  lessened. 

(3)  Didymograptus  n  i  t  i  d  u  s  holds  a  position  between  D  . 
patulus  and  D.  extensus,  both  of  which  it  approaches  in  some 
of  its  many  slight  varieties.  With  D  .  extensus  it  has  in  common  the 
size  of  the  sicula,  inclination  and  overlap  of  the  thecae,  but  differs  in  the 
considerably  closer  arrangement  of  the  thecae.  There  is  no  Tetragraptus 
known  in  the  Lower  Siluric  to  which  D .  n  i  t  i  d  u  s  could  be  readily 
referred ;  and  we  incline  to  the  opinion  that  it  is  a  derivative  from  another 
species  of  Didymograptus,  possibly  D.  extensus. 

(4)  Bry  ograptu  s  lapworthi,  Didymograptus  nichol- 
s  o  n  i  and  D  .  e  1 1  e  s  i . 


Characters  of  thecae  etc. 

Number  of  thecae 
in  10  mm 

Inclination  of 
thecae 

Overlap 

Bryograptus 

lapworthi 

Didymograptus 

Slender  forms ;  thecae 

10 

15-20° 

w 

with  straight  or  slight¬ 
ly  concave  outer  walls ; 

10-11 

o 

o 

CM 

i-i 

nichol sou  i 

apertures  appear  near¬ 
ly  straight 

Did.  ellesi 

10-12 

8-10° 

i 

558 


NEW  YORK  STATE  MUSEUM 


The  similarity  between  the  first  two  species  which  is  indicated  by  the 
measurements  of  the  thecae,  is  still  increased  by  the  narrow,  rigid  and 
straight  character  of  the  branches,  and  their  approximately  equal  angles  of 
divergence  as  well  in  the  proximal  as  also  in  the  distal  portions  (110°-140° 
in  Bryograptus  lapworthi  and  110°-130°  in  Didymograptus 
nich  olsoni)  .  The  similarity  between  the  rhabdosomes  in  our  material  is 
so  close  that,  where  only  broken  branches  or  young  colonies  are  observed,  the 
distinction  between  the  two  is  very  difficult. 

Didymograptus  gracilis  is  considered  by  Miss  Elies  to  belong 
to  the  same  series  as  D.  nicholsoni.  There  exists  indeed  an  unmis¬ 
takable  similarity  in  the  habit  of  the  form  which  is  referred  in  the  mono¬ 
graph  of  the  British  graptolites  toD.  gracilis  Tornquist,  to  the  species 
of  Bryograptus  and  Didymograptus  referred  here  to  the  same  series.  This 
similar  habit  is  produced  by  the  relative  rigidity  and  straightness  of  the 
branches  and  their  similar  angles  of  divergence  as  well  as  the  slender 
character  of  the  thecae.  We  show  however  in  the  systematic  part  of  this 
memoir  [p.561  ]  that  the  British  form  belongs  to  a  different  species,  which 
it  is  here  proposed  to  term  D .  e  1 1  e  s  i .  The  last  represents  indeed  a 
derivative  of  D.  nicholsoni  with  looser  arrangement  of  the  thecae; 
while  the  typical  D.  gracilis,  which  is  also  present  in  our  fauna,  belongs 
to  a  different  evolutionary  series  [p.561]. 

(5)  D.  spinosusis  the  only  species  of  Didymograptus  known  to  have 
possessed  dorsal  and  apertural  spines.  There  is  however,  also  a  species  of 
Tetragraptus,  T.  acanthonotus  Gurley,  found  in  the  Levis  shales, 
which  differs  from  the  other  species  of  Tetragraptus  by  the  same  features. 
Yet  a  comparison  of  the  characters  of  the  thecae  brings  out  the  fact  that  the 
latter  species  is  a  much  coarser  form,  with  uniformly  wider  branches,  less 
closely  arranged  thecae  (which  is  only  coincident  with  the  coarser  structure 
of  the  whole  colony)  and  more  inclined  thecae.  It  is  hence  doubtful  whether 
the  presence  of  the  spines  in  both  species  indicates  the  parallel  acquisition  of 
a  new  character  in  the  related  forms  or  a  closer  phylogenetic  bond. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


559 


(6)  The  peculiar  Deep  kill  form,  Goniograptus  perflexilis, 
which  is  characterized  by  very  long  thecae,  thin  branches,  very  long  branches 
of  the  first  order  (“  funicle  ”)  and  large  divergence  of  the  branches  of  the 
second  order,  bears  an  extremely  striking  similarity  in  general  appearance  to 
a  somewhat  more  robust  Dichograptus  from  the  Skiddaw  slates,  viz  Dicho- 
g  r  a  p  t  u  s  separatus  Elies. 

The  following  table  gives  a  comparison  of  the  characters  pertaining  to 
their  general  appearance. 


Length  of 
branches  of 
first  order 

Divergence  of 
branches  of  second 
order 

Divergence  of 
branches  of  third 
order 

Number  of  thecae 
in  10  mm 

Width  of 
branches 

Goniograptus 

6  mm 

90°-100° 

o 

o 

1 

OO 

O 

o 

6-7 

.4 

perflexilis 

Dichograptus 

6.35  mm 

105° 

-T 

O 

o 

13 

.5 

separatus 

If  we,  however,  compare  the  characters  of  the  thecae,  we  find  that  in 
Dichograptus  separatus  they  are  more  closely  arranged,  and  more 
inclined.  As  these  differences  are  indicative  of  a  condensation  of  the  growth 
of  the  branches,  they  may  not  be  so  prohibitive  of  a  phyletic  connection 
between  the  two  species  as  they  would  appear  at  first  glance. 

Indeed,  a  perusal  of  the  tables  of  measurements  of  the  thecae  of  the 
various  supposed  phyletic  series  distinctly  brings  out  the  fact,  that  in  a 
large  percentage  of  the  groups  the  thecal  arrangement  shows  progressive 
condensation  in  successive  forms.  To  cite  the  more  notable  instances,  the 
inclination  of  the  thecae  increases  in  the  group  leading  from  Bryograptus 
ramosus  var.  cumbrensis  to  Didymograptus  indentus  from  20° 
to  30°,  in  that  leading  from  the  same  species  to  D.  furcillatus  from  20°  to 
45°  and  in  that  leading  again  from  the  same  species  to  D ..  b  i  f  i  d  u  s  from  20° 
to  45°,  while  the  number  of  thecae  at  the  same  time  increases  from  9-10  to 
13-14  within  10  mm. 

As  the  subequal  length  of  the  “funicles”  of  both  species,  Gonio¬ 
graptus  perflexilis  and  Dichograptus  separatus,  is  proof  of 


500 


NEW  YORK  STATE  MUSEUM 


the  originally  equal  dimensions  of  their  thecae,  the  differences  found  in  the 
closeness  of  arrangement  and  inclination  of  the  thecae  can,  also,  here  be 
attributed  with  propriety  to  a  condensation  of  the  branches.1 

(7)  A  small  series  of  Tetragrapti  and  Didymograpti  of  the  Deep  kill 
fauna  is  characterized  by  projecting  acute  or  mucronate  apertures  of  the 
thecae.  The  accompanying  table  gives  the  detailed  characters  of  the  thecae 
of  these. 


Character  of  thecae 

Number  of  the¬ 
cae  in  10  mm 

Angle  of  diver¬ 
gence 

Overlap 

Bryograptus  lap¬ 
worthi 

Thecae  slender 

straight,  with 

abruptly  widen¬ 
ing  projecting 
apertures 

10 

15°^20° 

Tetragraptus  tar- 
ax  a  c  u  m 

12 

4°  proxirn- 
ally;  40°- 
60°  dis¬ 
mally 

i  proximally ; 
£  distally 

I)  i  dymograptus 
acutidens 

11 

15° 

w 

Didymograptus 
c  u  s  p  i  d  a  t  n  s 

11-12 

18°  proxi- 
mally  ;40° 
distal  ly 

i-i 

The  table  shows  readily  that  the  thecae  of  these  species  agree  well 
in  their  arrangement,  inclination  and  overlap.  The  last  three  named 
species  are  still  more  closely  united  by  the  character  of  the 
aperture,  mentioned  above,  which  attains  its  extreme  development  in 
Didymograptus  cuspidatus,  which  also  is  the  last  appear¬ 
ing  form  of  the  series.  Bryograptus  lapworthi  does  not  possess 
the  typical  apertural  projections  of  the  group.  The  fact,  however, 
that  in  Tetragraptus  taraxacum  the  first  thecae  also  fail  to  present 
this  character,  but  agree  fully  with  those  of  B .  lapworthi,  is  good 

1  The  interesting  problem  of  the  tendency  to  a  condensation  of  the  thecae  is  treated 
more  fully  in  another  chapter  [p.569]. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


563 


evidence  of  the  derivation  of  T.  taraxacum  from  a  form  with  the 
thecal  characters  of  B.  lapworthi.1 

Bryograptus  lapworthi  can  be  considered  as  having  descended 
through  unknown  intermediate  forms  from  Staurograptus  dicho- 
tomus  var.  apertus  with  some  degree  of  certainty,  springing  from  the 
fact  that  the  character  and  arrangement  of  the  thecae  in  the  two  species  fairly 
agree  (number  of  thecae  11-13  in  10  mm  in  S.  dichotomus  var. 
apertus;  angle  of  inclination  25° ;  overlap  ^). 

(8)  A  series  with  strong  diagnostic  characters  is  that  leading  from 
Goniograptus  perflexilis  through  a  peculiar  flexuous,  four 
branched  form,  Tetragraptus  lentus,  to  D  i  d  y  m  o  g  r  a  p  t  u  s 
filiform  is  and  D.  gracilis. 


Character  of  thecae  etc. 

Number 
of  thecae  in 
10  mm 

Angle  of 
inclination 

Overlap 

Width 
of  branches 

Goniograptus 

perflexilis 

Thecae  extremely 
long,  narrow, 

very  little  widen¬ 
ing,  curved. 

Branches  of  first 
order  originating 
near  middle  of 
sicula 

6-7 

5° 

A 

Tetragraptus 

lentus 

6-10 

5° 

i 

.37 

Didymograptus 
filiformis  Tullb. 

8-10 

10°-15° 

i 

.25 

The  specific  names  of  all  four  species  express  the  thin,  flexuous 
character  of  the  branches,  which  is  due  to  the  extreme  length  (3  mm)  and 
narrowness  of  the  thecae,  as  well  as  to  their  small  overlap  (one  fourth)  and 
loose  arrangement  (6-10  in  the  space  of  10  mm). 

A  peculiar  character  which  these  forms  have  in  common  with  the 
Coenograptus  series,  also  to  be  derived  from  Goniograptus  per¬ 
flexilis,  is  the  origin  of  the  branches  about  midway  of  the  sicula. 

1  The  change  in  the  character  of  the  thecae  of  T.  taraxacum  has  been  discussed 
by  the  writer  in  another  connection  [1902,  p.589]. 


562 


NEW  YORK  STATE  MUSEUM 


In  Didymograptus  filiform  is  and  gracilis  this  feature  is  some¬ 
what  modified  in  so  far  as  the  two  branches  originate  in  unequal  distances 
from  the  apex  of  the  sicula,  one  in  the  middle  and  another  a  little  more 
distally. 

Didymograptus  gracilis  presents  thin  branches,  long,  narrow, 
little  overlapping,  remote  thecae,  similar  to  the  members  of  this  group  ;  and, 
also,  its  first  two  thecae  originate  at  different  levels  as  in  D .  filiformis. 
It  is,  nevertheless,  doubtful  whether  it  represents  more  than  a  later  paral¬ 
lelism  to  the  forms  of  this  series. 

A  comparison  of  the  number  of  dichograptid  species  cited  in  the  fore¬ 
going  discussion  and  the  considerably  greater  number  of  forms  known 
from  the  Lower  Champlainic  graptolite  beds,  proves  readily  that  still  a 
considerable  number  of  species,  specially  of  the  genera  Tetragraptus  and 
Didymograptus,  have  not  been  connected  with  older  forms  with  a  greater 
number  of  branches.  Such  a  comparison  will  also  show  that  the  number 
of  species  increases  considerably  as  we  proceed  from  the  earlier  multi- 
ramous  Clonograptus  and  Bryograptus  toward  Didymograptus.  This 
stands,  of  course,  in  accordance  with  the  general  fact  of  the  multiptication 
of  types  during  the  time  of  the  progressive  development  of  a  race.  As, 
hence,  the  number  of  known  spjecies  of  Didymograptus  is  considerably 
greater  than  that  of  Tetragraptus,  it  is  evident  that  not  every  Didymo¬ 
graptus  can  have  its  Tetragraptus,  and  that  either  several  species  of  Didymo¬ 
graptus  have  developed  from  the  same  sp>ecies  of  Tetragraptus  or 
spjecies  of  Didymograptus  have  become  themselves,  the  radicles  for  new 
species  of  the  same  genus.  The  latter  alternative  is  strongly  suggested 
by  the  great  similarity  of  several  spjecies  of  Didymograptus  among 
themselves,  as  among  D  .  a  f  f  i  n  i  s  and  D .  nicholsoni;  or 
between  D.  extensus  and  D.  nitidus;  or  between  D .  (gib- 
berulus)  c  a  d  u  c  e  u  s  and  D .  forcipiformis. 

Our  observation  of  the  similarity  between  Clonograptus 
(Staurograptus)  dichotomus  and  certain  species  of  Bryograptus 
and  of  the  fact  that  a  laterally  compressed  Clonograptus  can  only  with 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


563 


difficulty  be  distinguished  from  a  Bryograptus  [p.616  and  pl.2]  suggest  to 
us  the  inference  that  Bryograptus  is  derived  from  Clonograptus  by  a 
suppression  of  half. of  the  primary  dichotomies  and  a  retention  of  the 
irregular  branching.  Moreover,  the  difference  between  the  multiramous 
Dictyonema  and  the  proximally  biramous  Bryograptus  is  still  too  great 
to  warrant  the  assumption  of  a  direct  derivation  without  the  intercalation 
of  forms  such  as  Clonograptus  with  fewer  branches  than  Dictyonema  has 
and  more  than  Bryograptus  has. 

The  great  similarity  in  the  exterior  aspects  of  the  proximal  portions 
of  the  rhabdosomes  of  Clonograptus  (Staurograptus)  dicho- 
tomus  and  Dictyonema  flabelliforme  is  pointed  out  under  the  des¬ 
cription  of  these  forms  [ see  also  pl.1,  fig.15;  pl.2,  fig. 9].  This  is  due  to  the 
similar  initial  branching  and  may  be  entirely  accidental,  but  is  certainly  quite 
suggestive  of  a  common  ancestor  in  view  of  the  presence  of  these  two 
forms  alone  in  the  lowest  graptolite  bed. 

For  these  reasons,  we  incline  to  the  view  that  all  Dichograptidae  will 
be  finally  traced  back  to  Clonograptus  forms,  from  which  one  part  develops 
through  Bryograptus,  the  other  through  Loganograptus  and  Dichograptus, 
into  Tetragraptus  and  Didymograptus  stages. 

The  PJiyllograptidae  have,  by  Holm’s  investigation,  been  shown  to  be 
Tetragrapti  of  the  recumbent  series,  the  branches  of  which  have  coalesced 
with  their  dorsal  sides.  A  transitional  form,  in  which  the  proximal  parts 
of  the  four  branches  also  are  said  to  be  united,  is  reported  under  the  name 
Tetragraptus  phyllograptoides  (Linnarsson  ms)  from  Sweden 
[, see  Elies,  p.534].  This  would  seem  to  lead  from  Tetragraptus  bigsbyi 
to  Phyllograptus  angustifolius.  Whether  the  other  species 
of  Phyllograptus  branched  off  from  this  radical  form  of  the  group,  or 
whether  also  the  Phyllograptidae  are  of  polyphyletic  origin,  has  not  yet 
been  investigated.  At  any  rate,  no  forms  of  Tetragraptus  are  known  to 
which  the  other  species  of  Phyllograptus,  P .  ilicifolius,  P .  typus 
and  P .  anna,  could  be  readily  referred.  There  seems  to  have  taken 
place,  not  only  a  condensation  of  the  branches  and  a  resulting  curving 


564 


NEW  YORK  STATE  MUSEUM 


and  subradial  arrangement  of  the  thecae,  but  also  a  differentiation  of  the 
character  of  the  apertures,  which  manifests  itself  principally  in  the  vary¬ 
ing  development  of  the  apertural  mucros  or  spines. 

In  the  absence  of  other  species  of  Tetragraptus,  which  could  be  con¬ 
sidered  radicles  of  species  of  Phyllograptus,  and  the  distinct  succession  of 
the  forms  in  time,  it  is  more  probable  that  the  Phyllograptidae  form  a 
compact,  monophyletic  group.  Yet  even  in  this  small  group  it  is  evident 
that  Phyllograptus  ilicifolius  and  its  successor,  P .  anna,  are 
more  closely  related  with  each  other  than  with  P.  angustif'olius  and 
P .  t  y  p  u  s . 

A  peculiar  branch  of  the  Dichograptidae,  on  whose  genetic  relations 
hitherto  no  light  has  been  thrown,  are  the  Coenograptidae .  These  do  not 
appear  till  the  Upper  Champlainic,  or  Ordovicic  horizons  are  reached.  The 
path  of  their  derivation  has  been  pointed  out  by  the  discovery  of  an  ancestral 
type  of  the  family,  viz  Sigmagraptus  praecursor  [pl.5,  fig.13]  in 

the  Deep  kill  fauna.  This  interesting  form  pos¬ 
sesses  two  principal  stems,  from  which  undivided 
branches  originate  alternately  on  either  side.  The 
principal  stems  foreshadow  already  in  their  curva¬ 
ture  the  peculiar  sigmoidal  curve  of  those  of  Coeno- 
graptus.  In  Coenograptus  the  branches  of  one  half 
of  a  rhabdosome  are  turned  to  one  side,  those  of 
the  other,  turned  to  the  opposite  side.  On  wrell 
preserved  specimens  of  C.  gracilis  [see  text  figure],  I  have  however 
been  able  to  observe  that  every  second  branch  bends  across  the  principal 
stem  to  the  same  side  as  the  preceding  branch,  which  makes  the  original 
arrangement  of  the  branches  identical  with  that  of  Sigmagraptus.  Both 
have  also  in  common  the  long,  little  overlapping,  slender  thecae  and  thin 
branches. 

A  peculiar  feature  of  Coenograptus  as  well  as  of  Sigmagraptus  is  the 
divergence  of  the  principal  stems  near  the  middle  of  the  sicula,  wdiich 
leaves  the  apertural  end  of  the  sicula  protruding  fully  beyond  the  stems. 


Fig.  15  Coenograptus  gra¬ 
cilis  Hall  sp.  x4  (Copy  from 
Ruedemann) 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


565 


The  feature  of  a  long  aperturally  projecting  sicula  we  meet  again  as  a 
marked  characteristic  of  the  two  peculiar  new  forms  here  referred  to 
Goniograptus  as  G.  perflexilis  and  G.  geometricus  [pi. 8,  fig.lo 
and  39].1  The  former  of  these  agrees  in  the  length  of  the  “funicle,”  length 
and  low  inclination  of  thecae,  slenderness  of  branches  and  relative  distance 
of  their  points  of  divergence  from  the  principal  stem,  and  their  angles  of 
divergence  so  closely  with  Sigmagraptus  praecursor,  that  there  is 
no  doubt  in  my  mind  of  the  phylogenetic  relationship  of  the  two.  \_See  follow¬ 
ing  table  of  measurements] 


Character  of  thecae  and 
branches 

Length  of 
branches 
of  first 
order 

Number 
of  thecae 
in  10  mm 

Inclina¬ 
tion  of 
thecae 

Overlap 

Angleof 
diverg¬ 
ence  of 
branches 

Width  of 
branches 

Goniograptus 

perflexilis 

4-6 

6-7 

•  5° 

80° 

.4 

Sigmagraptus 

praecursor 

Thecae  long,  slender 
Slender  branches 

2.8 

8-10 

12° 

i 

90° 

.3 

Coenograptus 

gracilis 

2 

8-10 

5°-15° 

W 

90° 

.5 

Sigmagraptus  praecursor  originated  from  Goniograptus 
perflexilis  by  the  failure  of  the  first  thecae  to  produce  two  principal 
stems  each  by  dichotomy.  The  one  branch  developed  has  retained  on  either 
side  of  the  sicula  the  oblique  position  to  the  “  funicle,”  the  result  being  the 
slightly  sigmoidal  curve  of  the  principal  stems. 


1  The  same  protrusion  of  the  sicula  beyond  the  point  of  origin  of  the  branches 
and  its  resulting  conspicuity,  are  found  also  though  not  so  typically  developed  in 
another  series  of  forms,  to  which  Tetragraptus  lentus,  Didym  ograp  tus 
filiform  is  and  D.  gracilis  belong  [p.561].  Also,  these  forms  are  derived 
from  Goniograptus  perflexilis.  It  is  further  very  notable  in  a  small 
paracmic  Tetragraptus  [T  .  pygmaeus;  pi.  12]. 

While  this  conspicuity  of  the  sicula  is  partly  due  to  the  slenderness  of  the  thecae, 
its  principal  cause  is  the  origin  of  the  branches  in  all  the  forms  at  a  point  very  near 
the  apical  end  of  the  sicula  [pl.12,  fig.ll]  and  the  abrupt  diverging  of  the  mother  thecae 
of  the  branches. 


566  NEW  YORK  STATE  MUSEUM 

In  the  same  way  as  Coenograptus  is  readily .  traced  through  Sigma- 
graptjis  to  Goniograptus,  which  clearly  is  a  derivative  of  Clonograptus,  the 
genera  Pterograptus  and  Pleurograptus,  at  present  united  with  Coenograptus 
in  a  small  separate  group  of  Dichograptidae,  also  appear  to  be  traceable  to 
Clonograptus. 

The  last  remaining  genus  of  the  Dichograptidae,  represented  in  the 
New  York  fauna,  is  Temnograptus,  a  coarse  multiramous  form  which 
at  present  can  not  be  connected  with  any  other  genus,  but,  by  exclusion, 
can  be  said  to  have  been  derived  from  some  species  of  Clonograptus  by 
transitional  stages  not  yet  known. 

If  we  represent  the  supposed  phylogeny  of  the  Dichograptidae  in  the 
customary  form  of  a  tree  and  its  branches  [p.553]  we  find  at  the  base  the 
genus  Clonograptus,  from  which  one  stem  leads  up  through  Stauro- 
graptus  dichotomus  var.  a  p  e  r  t  u  s  to  Bryograptus,  another  through 
other  forms  of  Clonograptus.  From  both  of  these  arise  numerous  upshoot- 
ing  branches  much  as  in  stunted  willow  trees,  some  of  which  at  times 
again  send  off  twigs.  If  we  lay  a  horizontal  plane  low  down  through 
these  bundles  of  branches,  it  passes  through  forms  which,  though  belonging 
to  various  offshoots  or  lines  of  descent,  all  have  in  one  bundle  the  character 
of  a  Bryograptus  and  in  the  other  that  of  a  Dichograptus  or  a  Goniograptus. 
Laying  a  higher  horizontal  plane  through  the  branches,  we  intersect  the 
forms  all  in  the  Tetragraptus  stage,  and  the  ultimate  twigs  are  nearly  all  in 
the  Didymograptus  stage. 

These  horizontal  planes  represent  a  certain  stage  of  development  as  for 
instance  the  Tetragraptus  stage,  passed  through  by  all  the  series  repre¬ 
sented  here  as  upshoots  of  Dichograptidae  at  approximately  the  same  time 
in  geologic  history.  At  the  intersections  of  the  plane  with  the  branches 
we  find  hence  the  species  which,  while  belonging  to  different  races,  have 
all  reached  the  same  stage  in  the  gradual  reduction  of  the  number  of 
branches.  These  species  have  been  grouped  into  the  genera  as  they  are 
at  present  understood.  We  have  here,  therefore,  a  remarkably  distinct  case  of 
the  law  of  parallelism  in  development. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


567 


Some  peculiar  side  branches  are,  that  leading  through  Goniograptus 
and  Sigmagraptus  to  Coenograptus,  another  producing  through  T  e  t  r  a  - 
graptus  (bigsbyi)  similis  and  others  the  Phyllograptidae,  and  the 
branch  represented  by  the  Temnograptidae. 

The  appended  diagram  is  intended  to  illustrate  these  supposed  phylo¬ 
genetic  relations  of  the  species  of  the  Dichograptidae  and  the  character  of 
the  present  genera  as  stages  in  a  parallel  development  of  various  series.  It 
is  based  on  Nicholson’s  and  Marr’s,  and  Elles’s  suggestions,  the  phylogenetic 
diagram  furnished  by  the  last  named  author,  and  the  observations  of  phyletic 
series  in  the  New  York  fauna,  cited  above.  We  have,  for  reasons  stated 
before,  referred  all  forms  to  Clonograptus  as  a  radicle,  added  the  series 
recognizable  in  our  fauna  and  restricted  ourselves  as  much  as  possible  to 
forms  found  either  here  or  in  the  Canadian  extension  of  the  beds. 

d  Supposed  causes  of  the  evolution  of  the  Dichograptidae.  A  study  of 
the  stages  through  which  the  various  series  of  Dichograptidae  pass  during 
their  parallel  development  shows  that  the  whole  race  begins  with  multi- 
ramous,  very  irregularly  branching  forms  and  ends  with  pauciramous, 
very  regularly  branching  and  symmetric  forms.  This  tendency  makes  itself 
manifest  whether  we  follow  a  series  leading  from  the  Cambric  Clonograptus 
through  .  Goniograptus  to  Sigmagraptus  and  Coenograptus,  or  from  the 
same  genus  to  Temnograptus,  or  through  Bryograptus  to  Tetragraptus  and 
Didymograptus,  or,  finally,  through  Dichograptus  to  the  same  last  named 
stages  of  development. 

As  explanation  for  this  tendency,  Nicholson  and  Marr  suggest  its 
connection  with  the  supply  of  food.  They  argue  that  symmetry  in  the 
arrangement  of  the  branches  would  tend  to  insure  an  equal  supply  of  food 
to  each  branch ;  and  that  the  fewer  the  branches,  the  greater  the  supply  of 
food  to  the  entire  organism. 

It  strikes  us  that  this  suggestion  does  not  take  sufficient  notice  of  the 
irregular  branching,  multiramous  habit,  insisted  on  by  the  Dendroid ea, 
which,  as  Dendrograptus,  were  attached  by  thick  stems,  while  such  Dendroidea 
as  Dictyonema  flabelliforme,  which  were  clearly  suspended, 
become  symmetric  in  their  growth. 


568 


NEW  YORK  STATE  MUSEUM 


As,  now,  according  to  Lapworth’s  theory,  the  Dichograptidae  were 
suspended  forms,  derived  from  sessile  bentlionic  forms,  it  seems  necessary 
for  us  to  take  into  account  the  influence  of  the  suspension  from  a  mostly 
very  thin  thread  —  often  indeed,  as  in  T  etragraptus  bigsby.i,  etc., 
strikingly  thin  in  relation  to  the  size  of  the  colony  —  on  the  gradual  production 
of  the  symmetric  arrangement  of  the  branches.  An  irregular  growth  in  a 
suspended  colony  is  clearly  liable  to  lead  to  a  disturbance  of  the  equilibrium 
of  the  colony,  the  consequent  sinking  of  one  half  and  rising  of  the  opposite 
half  of  the  rhabdosome  and  a  resulting  disarrangement  of  the  normal  position 
of  the  thecae.  The  nicety  of  balancing  is  hence  quite  plausibly  one  of 
the  ends  sought  in  the  often  rigidly  symmetric  arrangement  of  the 
branches. 

The  reduction  of  the  number  of  branches,  however,  goes  hand  in  hand 
with  a  lengthening  of  the  remaining  branches,  so  that  the  total  length  of 
the  branches  or  of  the  number  of  thecae  in  the  later  pauciramous  forms 
is  not  only  not  smaller  but  materially  greater  than  in  the  early  multi- 
ramous  forms;  for  we  see  everywhere  the  numerous  short  branches  of 
the  Clonograptus  and  Bryograptus  forms  followed  by  the  immensely  long 
branches  of  the  species  of  Loganograptus,  Dichograptus,  Temnograptus, 
Coenograptus  and  Tetragraptus.  We  can  not  for  this  reason  believe  that 
the  reduction  of  the  number  of  branches  could  have  been  for  the  purpose 
of  increasing  the  food  supply  of  the  entire  organism,  but  incline  rather  to 
the  belief  that  this  reduction  was  incidental  to  the  assumption  of  the  symmetric 
form. 

If  we  contrast  Clonograptus  M’ith  its  great  power  of  branching  by 
dichotomy  with  the  last  sprouts  of  the  race,  the  species  of  Azygograptus, 
which  are  altogether  unable  to  produce  dichotomies,  it  appears  that  the 
tendency  to  a  reduction  of  the  number  of  branches  finally  became  so  fixed 
that  the  series  shot,  so  to  say,  beyond  the  mark,  and  the  power  of  branching 
was  finally  lost  altogether. 

A  peculiar  feature  of  the  species  of  Didymograptus  is,  that  those  which 
are  rigidly  horizontal  attain,  at  least  in  the  Lower  Champlainic  fauna,  a  size 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


569 


much  surpassing  that  of  the  dependent,  declined  or  reclined  forms.  This 
is  exemplified  specially  by  Didymograptus  extensus,  nitidus 
and  p  a  t  u  1  u  s .  As  my  material  shows  that  these  forms  also  pos¬ 
sessed  but  an  extremely  short,  if  any,  nema,  and  that  the  primary  disk, 
which  was  large,  was  closely  affixed  to  the  sicula  and  to  the  center 
of  the  colony,  the  inference  is  very  plausible  that  these  long  branches 
were  closely  adhering  to  the  underside  of  floating  objects,  perhaps  seaweeds, 
similarly  as  the  colonies  of  some  bryozoans  are  at  present.  In  the  Upper 
Champlainic  appear  also  dependent,  or  rather  flexuous  types  of  Didymo¬ 
graptus  with  branches  of  astonishingly  large  linear  dimensions. 

Another  tendency  of  development,  becoming  manifest  among  the 
Dichograptidae  and  incidentally  mentioned  above,  is  that  of  condensing  the 
branching  by  a  close  arrangement  of  the  thecae.  This  is  largely  accom¬ 
plished  by  giving  the  thecae  a  more  oblique  position  to  the  axis  of  the 
branch.  The  gradual  increase  in  the  angle  of  inclination  in  several  series  has 
been  pointed  out  above  [p.559]. 

The  branches  of  several  species  recapitulate  this  process  in  their 
individual  ontogenetic  development,  as  we  have  shown  in  a  former  paper 
[1902,  p.587]  in  the  cases  of  Go  niograptus  thureaui  and  Tetra- 
graptus  fruticosus.  In  these  forms  the  branches  begin  with  long- 
slender  thecae,  with  a  small  angle  of  inclination.  As  a  rule  gradually,  but 
sometimes  quite  abruptly,  as  in  T .  fruticosus,  the  thecae  become 
more  closely  arranged  by  a  decrease  of  overlap,  and  more  inclined.  In  the 
later  species  they  also  become  provided  with  apertural  mucros,  which  must 
be  a  later  acquisition  of  the  series  [ see  fig.  11,  p.531]. 

The  cause  of  the  condensation  of  the  branches  is  to  be  found  in  the 
reclined  position  assumed  by  them  in  an  endeavor  of  the  rhabdosomes, 
which  have  become  suspended,  to  restore  to  the  zooids  their  original  erect 
position.  By  this  ascending  growth  of  the  branches,  they  lengthen  in  the 
direction  of  the  point  of  fixation  or  support,  whatever  this  may  have 
been,  thus  necessitating  a  corresponding  lengthening  of  the  supporting 
nema  and  thereby  endangering,  by  undue  longitudinal  growth,  the  fixation 


570 


NEW  YORK  STATE  MUSEUM 


of  the  colony.  It  was  hence  of  advantage  to  shorten  the  branches  in  the 
forms  where  they  are  reclined.  For  this  reason  we  find  the  broad,  short 
branches  in  Tet  rag  rapt  us  (bigsbyi)  similis  and  D  i  d  y  m  o  • 
g  rapt  us  (gibbe  ruins)*  caduceus,  species  in  which,  and  in  the 
Phyllograptidae,  the  reclining  has  gone  the  farthest. 

e  Classification  adopted  here.  We  have  shown  in  the  preceding  dis¬ 
cussion  that  the  phylogenetic  relations  of  the  principal  groups  are  not  yet 
elucidated,  while  those  of  the  families  and  genera  as  far  as  known  indicate 
the  necessity  of  a  future  revision  of  the  present  more  or  less  artificial 
groupings.  It  would,  under  these  circumstances,  be  premature  to  attempt 
new  classifications ;  and  we  use  here  that  still  in  general  use  and  based  on 
Lapworth’s  Improved  Classification  of  the  Rhabdophora ,  with  such  modi¬ 
fications  as  are  suggested  by  later  investigations,  and  which  we  cite  here 
briefly. 

Lap  worth  comprised  under  the  Rhabdophora  all  graptolites  with  the 
exception  of  the  dendroid  forms,  at  that  time  still  doubtfully  referred  to 
the  graptolites.  For  the  latter  the  term  Dendroidea  proposed  by  Nicholson 
is  currently  used.  The  Rhabdophora  were  divided  by  Lapworth  into  the 
Graptolitidae  and  the  Retioloidea. 

As  is  indicated  by  the  similarity  of  the  thecae  of  various  Retioloidea 
to  those  of  forms  of  Diplograptus  and  Climacograptus,  and  by  the  early 
appearance,  in  Retiograptus,  but  late  acmic  development  of  the  group  as  a 
whole  (after  that  of  the  Diplograptidae  proper),  this  group  is  of  polyphyletic 
origin  and  composed  of  terminals  of  various  series  which  have  adapted 
themselves  in  a  parallel  manner  to  the  floating  habit  of  the  graptolites 
[p.518].  We  have,  for  this  reason,  not  recognized  here  the  order  Retioloidea 
but  united  the  single  representative  in  our  fauna  (Retiograptus)  with  the 
Climacograptidae. 

Freeh  has  divided  the  graptolites  into  two  orders,  the  Axonolipa 
and  Axonophora,  according  to  the  absence  or  presence  of  an  axis.  While 
we  have  noted  before  [p.552]  that  this  axis  may  not  in  all  genera  be  a 
homologous  organ,  and  hence  its  recognition  as  a  diagnostic  character  is 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


571 


not  irreproachable,  there  is  little  doubt  that  by  it  two  groups  of  the 
Graptoloidea  can  be  distinguished,  which  also  differ  in  other  structural 
features  and  which  are  separated  in  time.  These  are  the  Dichograptidae 
and  Diplograptidae  in  their  widest  sense.  Freeh,  however,  unites  under  the 
Axonolipa  the  Dendroidea  and  the  Dichograptidae,  two  groups  which,  by 
the  character  of  their  thecae  and  their  mode  of  growth,  appear  to  us  too 
widely  separated  to  be  united  with  propriety  in  one  order.  We'  have 
for  this  reason,  retained  the  original  division  into  the  orders  Dendroidea 
and  Grraptoloidea,  and  divided  the  latter  into  the  suborders  Graptoloidea 
Axonolipa  and  Graptoloidea  Axonophora.  Neither  of  these  principal 
groups  can,  at  present,  be  genetically  connected  with  any  of  the  others, 
while  the  closer  genetic  relation  of  their  subdivisions  is  little  to  be  doubted. 

(1)  The  order  Dendroidea  is  represented  in  our  fauna  by  the  family 
Dendrograptidae  with  the  genera  Dendrograptus,  Dictyonema,  Desmograptus, 
Callograptus  and  Ptilograptus. 

(2)  The  order  Graptoloidea  is  divided  into  the  suborders  Graptoloidea 
Axonolipa  and  B2  Graptoloidea  Axonophora. 

The  suborder  Graptoloidea  Axonolipa  comprises  the  provisional  family, 
Dichograptidae  sensu  stricto,  the  Phyllograptidae  and  Coenograptidae.  The 
Dichograptidae  will  eventually  be  divided  into  the  series  of  genetically 
connected  forms  discussed  above.  For  the  present  it  seems  most  practical 
to  retain  the  old  terms  Clonograptus,  Bryograptus,  Goniograptus,  Logano- 
graptus,  Dichograptus,  Tetragraptus  and  Didyraograptus. 

The  small  family  Phyllograptidae  contains  but  one  genus, 
Phyllograptus. 

A  family,  Leptograptidae,  was  erected  by  Lapworth  to  receive  the 
genera  Coenograptus,  Nemagraptus,  Pleurograptus,  Amphigraptus  and 
Leptograptus.  Our  material  has  demonstrated  that  Coenograptus 
gracilis,  the  type  of  the  genus,  is  derived  by  a  new  form  of 
generic  value  for  which  we  have  proposed  the  term  Sigmagraptus,  from  a 
Goniograptus. 

A  peculiar  new  tenuous  tetragraptid  form,  here  described  as 


572 


NEW  YORK  STATE  MUSEUM 


Etagraptus  1  e  n  t  u  s ,  indicates  quite  distinctly  the  separate  path  of 
the  evolution  of  at  least  one  of  the  thin  biramous  graptolites  with  very 
remote  slender  thecae.  The  family  Leptograptidae  appears  hence  to  comprise 
several  entirely  different  evolutional  series.  We  have  for  this  reason 
separated  one  of  these  as  the  Coenograptidae. 

Also  the  genera  grouping  themselves  around  Temnograptus  are  very 
liable  to  be  found  eventually  to  constitute  a  separate  family,  which  is 
characterized  by  peculiarities  of  branching.  The  New  York  fauna  contains 
only  a  single  representative  of  the  genus  Temnograptus. 

The  suborder  Graptoloidea  Axonophora  does  not  appear  till  the  time  of 
the  last  of  the  zones,  whose  faunas  have  been  here  investigated,  and  it  does 
not  attain  its  principal  development  till  the  late  Lower  Siluric  and  the  Upper 
Siluric. 

Freeh  has  separated  the  Climacograptidae  from  the  Diplograptidae 
Lapw.  and  referred  the  genus  Retiograptus  to  the  Climacograptidae.  As 
the  direction  of  growth  and  shape  of  the  thecae  in  Climacograptus  are  very 
different  from  those  found  in  Diplograptus,  this  separation  seems  well  sup¬ 
ported  by  the  facts  and  is  adopted  here. 

With  the  Diplograptidae  have  here  been  united  the  genera  Gflosso- 
graptus  and  Trigonograptus,  the  latter  with  some  doubt  arising  from  the 
peculiar  direction  of  the  aperture,  which  is  different  from  that  of  other 
Diplograptidae. 

We  thus  obtain  the  systematic  arrangement  of  the  New  York  forms, 
which  is  given  in  the  following  synoptic  list  of  our  species. 


Synoptic  list  of  fossils  described 


Order  1  DENDROIDEA  Nicholson 
Family  dendrograptidae  Roemer 
Genus  dendrograptus  Hall 

Dendrograptus  flexuosus  Hall 
D.  (?)  succulentus  sp.  nov. 

D.  fluitans  sp.  nov. 


Genus  callograptus  Hall 
Callograptus  salteri  Jlall 
C.  cf.  diffusus  Hall 

Genus  ptilograptus  Hall 
Ptilograptus  plumosus  Hall 
P.  geinitzianus  Hall 
P.  tenuiesimus  sp.  nov. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


573 


Genus  dictyonema  Hall 
Dictyonema  flabelliforme  Eichw.  sp 
I).  murrayi  Ilali 
D.  furciferum  sp.  nov. 

D.  rectilineatum  sp.  nov. 

Genus  desmograptus  Hopkinson 
Desmograptus  cancellatus  Hopkinson  sp. 

D.  intricatus  sp.  nov. 

Order  2  GRAPTOLOIDEA  Lapworth 
Suborder  A  GRAPTOLOIDEA  AXONOLIPA 
(Freeh)  Ruedemann  em. 

Family  dichograptidae  auct. 
Freeh  em. 

Genus  staurograptus  Emmons 
Staurograptus  dichotomus  Emmons 

S.  dichotomus  var.  apertus  var.  nov. 

Genus  clonograptus  Hall 
Clonograptus  cf.  flexilis  Hall  sp. 

Genus  goniograptus  McCoy 
Goniograptus  thureaui  McCoy 
G.  geometricus  sp.  nov. 

G.  perflexilis  sp.  nov. 

Genus  loganograptus  Hall 
Loganograptus  logani  Hall 

Genus  dichograptus  Salter 
Dichograptus  octobrachiatus  Hall  sp. 

Genus  temnograptus  Nicholson 
Temnograptus  noveboracensis  sp.  nov. 

Genus  bryograptus  Lapwortli 
Bryograptus  lapworthi  sp.  nov. 

B.  pusillus  sp.  nov. 

Genus  tetragraptus  Salter 
Tetragraptus  quadribrachiatus  Hall  sp. 

T.  amii  Lapw.  ( Elies  tfc  Wood  em.) 

T.  fruticosus  Hall  sp. 


T.  clarkei  sp.  nov. 

T.  pendens  Elies 
T.  serra  Brongniart  sp. 

T.  similis  Hall  sp. 

T.  woodi  sp.  nov. 

T.  taraxacum  sp.  nov . 

T.  pygmaeus  sp.  nov. 

T.  lentus  sp.  nov. 

Genus  didymograptus  McCoy 
Didymograptus  extensus  Hall  sp. 

D.  nitiaus  Hall  sp. 

D.  patulus  Hall  sp. 

D.  similis  Hall  sp. 

D.  gracilis  Tornguist 

D.  acutidens  ( Lapw .)  Elies  <&  Wood  era. 

D.  cuspidatus  sp.  nov. 

D.  nicliolsoni  Lapw.  var.  planus  Elies  & 
Wood 

D.  filiformis  Tullberg 
D.  ellesi  sp.  nov. 

D.  tornquisti  sp.  nov. 

D.  spinosus  sp.  nov. 

D.  bifidus  Hall  sp. 

D.  nanus  Lapworth 

D.  caduceus  Salter,  Ruedemann  em. 

D.  forcipiformis  sp.  nov. 

D.  incertus  sp.  nov. 

Family  coenograptidae  nom.  nud. 

Genus  sigmagraptus  gen.  nov. 
Sigmagraptus  praecursor  sp.  nov. 

Family  phyllograptidae 
Lapworth 

Genus  phyllograptus  Hall 
Phyllograptus  ilicifolius  Hall 
P.  typus  Hall 
P.  angustifolius  Hall 
P.  anna  Hall 


574 


NEW  YORK  STATE  MUSEUM 


Incertae  sedis : 

Genus  strophograptus  gen.  nov. 
Strophograptus  tricliomanes  sp.  nov. 

Suborder  B  GRAPTOLOIDEA  AXONO- 
PHORA  Freeh 

Family  diplograptidae  Lapworth 

Genus  diplograptus  McCoy 
Diplograptus  dentatus  Brongniart  sp. 

D.  inutilis  Hall 
D.  laxus  sp.  nov. 

B.  longicaudatus  sp.  nov. 

Genus  glossograptus  Emmons 
Glossograptus  hystrix  sp.  nov. 

G.  echinatus  sp.  nov. 


Genus  trigonograptus  Nicholson 
Trigonograptus  ensiformis  Hall  sp. 

Family  climacograptidae  Freeh 
Genus  climacograptus  Hall 
Climacograptus  pungens  sp.  nov. 

C.  ?  antennarius  Hall 

Genus  retiograptus  Hall 
Retiograptus  tentaculatus  Hall 

Appendix,  graptolithi  incertae  sedis 
Genus  caryocaris  Salter 
Caryocaris  cf.  curvilineatus  Gurley 
Genus  dawsonia  Nicholson 
Dawsonia  monodon  Gurley 

D.  tridens  Gurley 


11  Taxonomic  relations  of  the  graptolites 

An  exhaustive  discussion  of  the  probable  taxonomic  relations  of  the 
graptolites  to  other  classes  of  organisms  does  not  lie  within  the  scope  of 
a  work  on  the  faunas  of  a  limited  district.  As  the  question  concerning 
these  relations  is  however  a  very  pertinent  one,  and  has  not  since  Hall’s 
memoir,  been  touched  in  the  American  literature,  we  notice  here  briefly  the 
present  status  of  the  problem. 

Hall  insisted  strongly,  as  Portlock  did  before  him,  on  the  sertularian 
affinities  of  the  graptolites.  Also  the  succeeding  investigators  who  made  a 
thorough  study  of  the  graptolites,  notably  Carruthers  and  Nicholson, 
maintained  the  hydroid  relations  in  their  publications.  Allman,  who  treats 
the  possible  affinities  of  the  graptolites  most  exhaustively  in  his  Monograph 
of  the  Gymnoblastic  Hydroids 1  came  to  the  conclusion  that  “  on  the  whole 
it  would  seem  that  the  graptolites  constitute  a  very  aberrant  liydrozoal 
group  having  manifest  affinity  with  the  Hydroidea,  to  which  they  are 


1  Also  printed  in  Ann.  and  Mag.  Nat.  Hist,  ser  4.  1872.  9  :  364-80. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


575 


connected  by  the  nematophore-bearing  genera  of  the  latter,  while  they  have 
also  important  points  of  connexion  with  the  Rhizopoda.” 

The  facts  which,  in  Allman’s  opinion  and  that  of  his  contemporaries, 
most  obviously  opposed  themselves  to  the  acceptance  of  the  hydroid  affinities 
of  the  graptolites  were  the  presence  of  a  solid  axis  (the  virgula)  and  the 
unconstricted  mode  in  which  the  thecal  cavity  opens  into  the  coenosarcal 
canal.  In  regard  to  the  first  fact,  Rhabdopleura,  a  living  bryozoan,  which 
stands  apart  from  the  others  by  the  possession  of  just  such  an  axis,  is 
pointed  out  to  show  that  the  graptolites,  while  provided  with  such  axes, 
might  nevertheless  have  preserved  in  all  respects  a  typical  hydroidal  structure. 
AVe  may  emphasize  here  what,  at  the  time  when  Allman’s  discussion 
■was  written,  was  not  yet  known,  namely  that  only  a  suborder  of  the 
Graptoloidea,  the  Axonophora,  possesses  this  axis,  that  the  same  is 
lienee  a  late  acquirement  and  not  a  diagnostic  character  of  the  class. 

On  account  of  the  absence  of  the  constriction  at  the  basis  of  the 
thecae,  Allman  compares  these,  not  with  the  hydrothecae  which  shelter  the 
zooids,  but  with  the  calycles  which  contain  the  nematophores  of  the 
Plumularidae.  The  nematophores  consist  of  nothing  but  protoplasm  which  has 
the  power  of  emitting  pseudopodia.  The  fact  of  the  presence  of  dimorphic 
thecae  in  the  Dendroidea,  discovered  since,  would  seem  to  lend  support 
to  the  possibility  of  the  suppression  of  one  of  these  thecal  forms  in  the 
Graptoloidea. 

More  recently  however  writers  have  been  less  positive  in  their  views 
and  have  emphasized  specially  the  following  facts.  (1)  That  the  graptolites 
not  only  begin  very  early  in  the  Upper  Cambric  but  even  become  extinct 
in  the  Middle  Devonic,  that  hence  an  enormous  lapse  of  time  separated 
the  hemera  of  the  graptolites  and  that  of  the  sertularians  and  of  other 
Ilydrozoa,  of  which  fossil  remains  are  known  only  from  relatively  young 
formations.  (2)  It  is,  as  Neumayr  [Stiimme  des  Thierreichs,  p.346]  has 
stated  lucidly,  a  wrong  tendency  to  endeavor  to  fit  all  fossil  forms  into  the 
system  of  living  organisms,  a  tendency  which  not  only  leads  to  forced  and 


576 


NEW  YORK  STATE  MUSEUM 


unsafe,  or  even  wrong  correlations,  but  also  gives  a  wrong  conception  of  the 
development  of  the  organic  world,  namely  that  of  a  great  monotony,  by  which 
paleontology  would  not  be  enabled  to  make  us  acquainted  with  wholly  new 
groups  of  forms. 

Wiman  also  strongly  urges  that  the  graptolites  can  not  be  brought 
under  any  of  the  now  existing  classes  of  animals.  To  the  placing  of  the 
graptolites  with  the  Hydroidea,  this  author  objects  on  the  ground  that  first 
there  is  no  hydroid  known  which  has  the  structure  of  a  graptolite,  and 
secondly  the  persons  of  the  first  order  of  the  graptolites  (the  thecae)  are 
bilateral  symmetric,  while  those  of  the  Hydroidea  possess  a  higher 
symmetry. 

The  possible  objection  that  hydroid  thecae  also  possess  a  bilateral 
symmetry  is  met  by  the  statement  that  this  can  be  explained  by  the  position 
of  the  individuals,  while  in  the  graptolites  the  sicula  already  possessed  a 
bilateral  symmetry.  But  it  is  not  to  be  overlooked  here  that  one  of  the 
principal  features  which  constitute  the  bilateral  symmetry  of  the  sicula,  viz  the 
position  of  the  virgula  within  one  of  the  Avails,  is  clearly  a  later  acquisition  of 
the  colony,  for  the  earlier  forms  have  no  solid  virgula,  and  it  has  hence  by 
acceleration  of  development  been  transferred  to  the  sicula.  In  a  rapidly 

i 

developing  group  such  as  the  graptolites  manifestly  were,  it  is  equally 
possible  that  the  bilateral  symmetry  of  the  thecae,  originally  induced  by 
their  position,  became  so  quickly  fixed  that  by  tacliygenesis  it  appeared 
already  in  the  sicula  in  a  manner  similar  to  the  appearance  of  the 
virgula. 

It  is,  further,  to  be  considered  that  the  sicula  consists  of  two  parts, 
an  apical  and  an  apertural  one.  The  latter,  which  is  the  bilateral  symmetric 
one,  had  clearly  the  properties  and  functions  of  a  theca  [p.520] ;  while  the 
initial  or  apical  part,  which  lacks  growth  lines,  was  the  original  embryo 
sheath.  The  latter,  however,  shows  to  my  knowledge,  a  higher  symmetry 
than  a  bilateral  one ;  and  such  higher  symmetry  was  hence,  probably,  also 
possessed  by  the  embryo. 


GRAPTOLITES  OF  NEW  YORK,  PART  l 


577 


Like  Neumayr  and  Wiman,  Freeh  also  holds  that  it  can  not  be  expected 
that  the  graptolites  will  show  any  close  relationship  to  any  living  class  of 
forms ;  but  urges  that  one  should  rather  expect  to  find,  the  terms  Hydrozoa 
and  Anthozoa,  based  on  living  forms,  unapplicable  to  the  paleozoic  types ; 
and,  on  noting  an  analogy  between  the  embryonal  development  of  the 
Axonolipa  and  that  of  the  tabulate  corals,  suggests  that  these  together 
with  the  Stromatoporidae  occupied  the  place  of  the  present  Hydrozoa.  It 
is  added,  however,  that  whoever  desires  to  force  the  graptolites  into  the  pres¬ 
ent  zoologic  system,  must  place  them  near  the  Hydrozoa. 

We  fully  agree  with  the  last  named  author  that  it  would  be  mislead¬ 
ing  to  attempt  to  unite  the  graptolites  with  any  class  of  living  forms,  but 
at  the  same  time  wish  to  emphasize  the  necessity  of  using  a  group  of 
similar  forms  as  means  of  reconstructing,  if  only  by  analogies,  the  picture 
of  the  organism  and  thereby  gaining  new  working  hypotheses  to  stimulate 
investigation.  Thus  Freeh  discusses  most  fully  the  relations  and  differences 
between  the  graptolites  and  the  Plumularidae,  and  that  directly  after  the 
statement  that  the  graptolites  can  not  be  expected  to  be  fitted  into  a  class  of 
living  forms. 

Moreover,  even  if  an  extinct  group  can  not  directly  be  placed  within 
the  confines  of  a  class  of  living  forms,  it  must  naturally  be  more  nearly  related 
to  one  group  of  organisms  than  to  all  others  that  exist  at  present;  and 
there  is  certainly  much  gained  for  the  understanding  and  elucidation  of  the 
extinct  forms,  if  this  group  is  found.  In  this  sense  the  present  writer 
adduced  the  Siphonophora  for  comparison,  when  describing  the  pneumatocyst 
of  Diplograptus ;  and  later  on  emphasized  the  close  similarity  between  the 
generative  cysts  observed  in  Diplograptus  and  the  “gonangia”  of  the 
sertularians ;  and  for  the  same  reason  the  Hydrozoa  have  been  used  through¬ 
out  this  treatise  as  a  standard  by  comparison  with  which  an  understanding  of 
the  graptolites  is  sought. 


578 


NEW  YORK  STATE  MUSEUM 


DESCRIPTIONS  OF  GRAPTOLITES 

Order  1  DENDROIDEA  Nicholson 
Family  dendrograptidae  Roemer 
DENDROGRAPTUS  Hall.  1865 

The  genus  Dendrograptus  was  erected  by  Hall  for  forms  with  a  strong 
.  main  stem  and  a  broad,  spreading,  shrublike,  variously  ramifying  frond. 
The  thecae  are  described  as  quite  distinct  and  angular  in  some  (the  type 
species  of  the  genus,  D.  hallianus  Prout),  of  obscure  form  in  others, 
while  in  still  others  they  are  shown  only  as  round  or  elliptic  pits  or 
pustules. 

Wiman  [1895,  1900]  has  been  able  to  isolate  and  investigate  under  the 
microscope  four  different  forms  which  he  refers  to  this  genus.  These  pos¬ 
sessed  an  internal  structure  similar  to  that  in  Dictyonema,  viz  a  composition 
of  three  different  kinds  of  thecal  tubes,  representing,  according  to  Wiman, 
nourishing,  and  budding  individuals  and  gonangia  [p.592].  In  those  three 
of  these  four  species  which  also  from  their  external  characters  would  be 
readily  placed  with  Dendrograptus,  all  branches  are  simple,  i.  e.  consist  of  but 
one  series  of  individuals. 

t 

There  is  no  doubt  that  eventually  the  internal  structure  v7ill  furnish 
the  means  of  recognizing  the  phylogenetic  relations  of  the  forms  united 
under  Dendrograptus  and  of  procuring  thereby  the  criteria  for  a  sharp  and 
natural  division  or  dissolution  of  the  genus,  which  clearly  contains  very 
different  elements.  It  has  evidently  been  made  the  receptacle  of  all  arbori- 
form  graptolites ;  and  the  fact  of  the  great  difference  of  the  thecal  apertures 
mentioned  by  Hall,  in  the  original  description  of  the  genus,  indicates  already 
its  heterogeneous  character.  We  see  at  present  no  other  way  than  referring 
a  species  like  the  D .  ?  succulentus  of  this  paper  to  this  genus,  as 
there  is  no  other  designation  extant  for  similarly  constructed  forms,  and  it 
would  be  unwise  to  undertake  the  dissolution  of  the  genus  by  external 
characters,  at  a  time  vrhen  it  becomes  probable  that  the  internal  characters 
will  furnish  safer  criteria  for  such  a  proceeding. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


579 


The  habits  of  the  forms  of  the  genus  indicate  more  than  those  of  any 
others  a  sessile  mode  of  life,  for  the  stout  trunk  and  the  irregular 
ramifications  remind  so  strongly  of  the  structure  of  recent  sessile  hydrozoans 
that  this  similarity  has  frequently  been  cited  as  suggestive  of  a  like  mode 
of  life  of  at  least  these  forms.  Moreover,  there  have  been  observed  basal 
expansions  of  the  stem,  assuming  the  form  of  irregular  bulbs  or  disks, 
which  also  would  be  most  readily  explained  as  organs  of  attachment.  It 
is  however  to  be  remembered  that  no  cases  of  actual  attachment  and  fixa¬ 
tion  have  yet  been  recorded,  and  that,  at  the  Deep  kill  at  least,  and  also 
in  the  Quebec  shale  and  apparently  in  Wales,  the  species  of  Dendrograptus 
occur  in  the  same  facies  and  associated  with  all  the  other  graptolites,  as 
Dictyonema,  Diplograptus,  Climacograptus. 

Dendrograptus  flexuosus  Hall 

Plate  4,  figure  5,  6,  8-10 

Dendrograptus  f  1  e  x  u  o  su  s  Hall.  Canadian  Organic  Remains,  decade  2.  1865. 

p.l27f,  pi.  17,  fig.l,  2 

Dendrograptus  flexuosus  Hopkinson  &  Lapworth.  Quar.  Jour.  Geol.  Soc. 
1875.  31:662f,  pl.36,  fig.3a-3d 

Dendrograptus  flexuosus  Roemer  &  Freeh.  Lethaea  palaeozoica,  Bdl.  1897. 
p.578 

Dendrograptus  cf.  gracilis  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t 
1902.  p.555 

Descriptiori.  Rhabdosome  broadly  flabellate  (or  infundibuliform  ?), 
attaining  a  length  of  an  inch  or  more.  Branches  radiating  from  a  short, 
stout  nemacaulus,  slender,  flexuous,  bifurcating  frequently  and  somewhat 
regularly,  diverging  at  first  under  a  considerable  angle,  but  soon  becoming 
subparallel,  the  distal  ones  somewhat  undulating.  Thecae  numbering  6-14 
in  10mm;  long,  narrow,  projecting  distinctly,  inclined  at  an  angle  of  about 
20° ;  apertural  margin  forming  an  angle  of  80°  with  the  axis  of  the  branch. 

Position  and  localities.  Common  in  graptolite  bed  2  (Tetragraptus 
zone)  and  rarer  in  graptolite  bed  3  (zone  with  D  i  d  ymograptus 
bifid  us)  at  the  Deep  kill. 


580 


NEW  YORK  STATE  MUSEUM 


Hall’s  types  came  from  a  coarse,  greenish  shale  at  Point  Levis,  in 
which  it  is  associated  with  Tet  rag  rapt  us  serra,  Phyllograptus 
t  y  p  u  s  and  Dendrograptus  fruticosus.  It  may,  hence,  hold 
there  the  same  position  as  at  the  Deep  kill.  Lap  worth,  Gurley  and 
Ami  did  not  observe  it  among  the  Canadian  forms;  data  as  to  its  exact 
horizon  can  not  therefore  be  obtained  from  their  lists.  Hopkinson  and 
Lap  worth  record  it  from  their  Lowrnr  Arenig  of  the  Road  Uchaf,  Ramsey  island 
and  the  Middle  Arenig  of  Whitesand  bay. 

Remarks.  From  the  mode  of  compression  of  certain  specimens  [fig. 6], 
in  which  the  branches  are  more  crowded  toward  the  marginal  portions  of 
the  frond,  and  from  the  more  or  less  circular  disposition  of  the  branches 
around  the  center  in  others,  it  would  appear  that  the  rhabdosome 
did  not  always  lie  fanlike  in  one  plane,  but  may  have  grown 
infundibuliform. 

This  species  is  characterized  by  the  numerous  and  close  bifurcations 
and  the  greater  divergence  of  the  proximal  parts  of  the  divisions  when 
compared  with  the  more  distal  ones,  a  feature  wdiich  becomes  still  more 
accentuated  in  D .  divergens.  Separated  fragments  of  the  rhabdosome 
offer  quite  varying  aspects  according  to  their  original  distance  from  the 
base.  Very  delicate  fronds  have  been  observed  [fig.  7  and  8]  in  which 
the  branching  is  very  close  and  the  thecae  also  very  closely  arranged  (as 
many  as  14  in  10mm),  while  in  other  features  they  do  not  differ  from 
coarser  fragments  of  the  basal  portions.  As  a  quite  perfect  specimen, 
figured  by  Hopkinson  and  Lapworth  [fig.3b,  ibid.\  shows  the  rhabdosome 
to  divide  distally  into  a  mass  of  closely  arranged  delicate  branches,  these 
finer  branched  fronds  have  here  been  directly  united  with  the  coarser  and 
broader  branches  in  the  same  species. 

A  still  more  striking  contrast  between  broad,  short,  basal  branches 
and  rather  abruptly  dividing  tufts  of  finer  branches,  was  observed  in  a 
new  species  from  the  horizon  -with  Diplograptus  dentatus,  viz 
D .  (?)  succulentus. 

The  great  difference  in  the  remoteness  of  the  thecae  between  different 
portions  of  the  rhabdosome  is  shown  in  figure  9. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


581 


Dendrograptus  (?)  succulentus  sp.  uov. 

Plate  4,  figures  1-4 

Dendrograptus  sp.  nov.  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.570 


Fig.  16  Dendrograptus  (?) 
succulentus  sp.  nov.  Frag¬ 
ment  which  shows  the  composition 
of  the  branches  of  numerous  tubes. 
Deep  kill.  x3.75 


Description.  Rhabdosome  very  robust  in  its  basal  parts,  branching- 
very  irregularly,  often  so  frequently  that  the  successive  branches  are 
nearly  in  contact ;  angles  of  branching  very  differ¬ 
ent  in  the  basal  parts ;  branches  abruptly  break¬ 
ing  up  into  pendent  tufts  of  frequently  dividing 
branchlets.  Thecae  not  projecting ;  thecal  aper¬ 
tures  small,  circular  depressions,  which  in  the  basal 
parts  are  found  apparently  irregularly  distributed 
around  the  entire  circumference  of  the  branches, 
while  on  the  thin  branches  a  serial  arrangement  is 
indicated.  On  the  latter  they  number  8  to  10  in 
10  mm.  Where  the  external  periderm  of  the 
branches  has  become  exfoliated,  their  composition 
of  fine  tortuous  thecal  tubes  is  observable. 

Position  and  localities.  Common  at  the  Deep  kill  in  the  shale  of  the 
horizon  with  Diplograptus  den  tat  us. 

Pemarics.  This  species  is  easily  distinguished  from  any  other  species 
of  Dendrograptus  known  to  the  writer  from  the  American  Lower  Siluric. 
D .  serpens  Hopkinson  and  Lapworth  from  the  lower  Llandeilo  of 
Abereiddy  bay  in  Wales  [1875,  p.665]  is  also  characterized  by  robust 
basal  branches  and  pendent  terminal  tufts  of  branchlets.  From  that  younger 
species  the  Deep  kill  form  is  readily  distinguished  by  its  less  diffuse  habit, 
much  closer  branching  and  more  rigid  and  ascending  character  of  the 
branches ;  and  the  much  more  rapid  decrease  in  thickness  of  the  more  distal 
branches.  D .  erectus  Hall,  from  the  Point  Levis  Tetragraptus  shales, 
of  which  only  the  basal  part  is  known,  possesses  also  ascending  branches ; 
the  latter  are  however  neither  so  closely  arranged  nor  so  thick  and  robust 
as  in  D .  succulentus. 


582 


NEW  YORK  STATE  MUSEUM 


The  species  received  its  name  from  the  extremely  broad  branches, 
which,  however,  have  become  entirely  flattened,  giving  them  the  impression 
of  having  been  very  thick  but  not  very  firm.  It  is  quite  apparent  that 
these  branches  of  massive  appearance  were  only  the  basal  parts  of  a  multi- 
ramous  form,  which,  gradually  tapered  into  the  more  delicate  distal  parts, 

and  that  the  latter  are  retained  only  in  exceptional 
cases,  as  in  the  tuft  on  the  specimen  represented  in 
figure  4. 

It  is  doubtful  whether  this  form  can  be  prop¬ 
erly  referred  to  Dendrograptus  with  D .  halli- 
s {fee u i e .Ffius^sp?  nov.p  Vart  of  a  n  u  s  Prout  as  the  genotype,  for  the  branches 

principal  stem  of  specimen  repro-  ,  , 

dueed  on  plate  4,  figure  4,  enlarged  show  no  trace  of  “  denticles  or  thecae,  but  seem 

to  show  arrangement  of  apertures. 

Deep  kin.  x5  to  be  composed  of  bundles  of  fine  tubes,  opening 

without  projections  on  the  surface  of  a  common  periderm.  Hall,  however, 
has  expressly  drawn  the  limits  of  his  genus  so  wide  as  to  embrace  forms 
in  which  the  cellules  “  appear  as  simple  indentations  on  the  surface  and 
those  in  which  they  are  distinctly  angular  with  the  denticles  conspicuous,” 
and  Idopkinson  and  Lapworth  [1875]  have  referred  like  forms  to  Dendro¬ 
graptus.  It  is  however  obvious  that  these  forms  differ  essentially  from 
species  with  projecting  thecae,  such  as  D.  flexuosus. 

Dendrograptus  fluitans  sp.  nov. 

Plate  4,  figures  11, 12 

Dendrograptus  sp.  nov.  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.555 

Description.  Rhabdosome  small  (?),  consisting  of  thin,  flexuous  stems 
which  bifurcate  rather  irregularly  and  terminate  in  long,  filiform  branches. 
Thecae  narrow,  three  times  as  long  as  wide,  closely  arranged,  numbering 
16  in  10mm;  apparently  only  a  short  distance  in  contact  with  each  other 
(about  one  fourth  of  their  length) ;  in  the  compressed  state  appearing  as 
acutely  pointed,  little  inclined  (about  20°)  denticles ;  outer  margin  concave, 
apertural  margin  slightly  convex,  recurving,  forming  an  angle  of  48°  with  the 
axis  of  the  branch. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


583 


Position  and  localities.  Rare  in  graptolite  bed  2  of  tbe  Deep  kill 
section,  belonging  to  tbe  Tetragraptus  horizon. 

Remarks.  Only  incomplete  rhabdosomes  have  been  observed.  These 
suggest  a  form  similar  in  its  habit  to  Hall’s  D.  flexuosus  from  the 
Levis  beds  of  Quebec.  The  latter  type  bifurcates,  however,  more  frequently 
and  regularly,  and  has  thecae  arranged  less  closely  by  one  fourth  and 
differently  shaped,  with  more  obtuse  apertural  processes  and  angles. 
In  the  corresponding  Skiddaw  horizon  no  Dendrograptus  has  been  found. 

CALLOGRAPTUS  Hall.  1863 

Since  the  erection  and  definition  of  the  genus  Callograptus  by  Hall 
in  his  work,  the  Graptolites  of  the  Quebec  Group ,  very  little  has  been  added 
to  his  observations  on  the  genus.  This  is  largely  due  to  the  fact  that  no 
more  representatives  of  the  same  have  been  found,  with  the  exception  of 
two  new  species  recorded  by  Hopkinson  and  Lapworth  from  Ramsey 
island  [1875]. 

Hall  based  his  genus  mainly  on  its  mode  of  branching  and  the  resulting 
aspect  of  the  rhabdosome ;  stating  that  it  has  “  numerous  slender  bifurcat¬ 
ing  branches  proceeding  from  a  strong  stem  or  axis,”  and  that  in  its  aspect 
it  is  intermediate  between  Dictyonema  and  some  forms  of  Dendrograptus; 
that  the  branches  are  sometimes  distantly  and  irregularly  united  by  trans¬ 
verse  dissepiments,  but  that  the  frond  has  not  the  regular,  reticulate  structure 
of  Dictyonema  and  differs  from  Dendrograptus  in  the  mode  of  branching  and 
the  form  of  the  thecae. 

The  microscopic  investigations  of  Wiman,  which  have  resulted  in  the 
demonstration  of  the  composite  character  of  the  thecal  structures  of  both 
Dictyonema  and  Dendrograptus,  have  for  lack  of  suitable  material  not  been 
extended  to  this  genus,  and  its  actual  relations  to  either  Dictyonema  or 
Dendrograptus  are  still  unknown.  Hall’s  material  did  not  permit  him  to 
determine  the  character  of  the  thecae,  the  latter  appearing  as  simple  oval 
impressions  on  the  surface  of  the  compressed  branches. 

While  the  shale  material  of  the  De’ep  kill  is  not  suited  for  an  elucidation 
of  the  internal  structure  of  the  branches,  the  observation  of  smaller  pores 


584 


NEW  YORK  STATE  MUSEUM 


seems  to  indicate  that  their  composition  is  similar  to  that  found  by  Holm, 
and  Wiman  in  Dictyonema ;  or  that  there  exist,  besides  the  larger  thecal 
tubes,  smaller  ones  which  have  separate  apertures  as  in  Dictyonema,  and 
that  they  do  not  empty  into  the  thecae  as  in  Dendrograptus.  While  Hall 
described  the  apertures  as  being  located  alternatingly  on  opposite  margins, 
his  somewhat  diagrammatic  drawing  shows  them  in  regular  series.  In  the 
Deep  hill  material  the  apertures  are  irregularly  scattered,  or  found  disposed  in 
a  manner  suggestive  of  a  long  spiral  distribution. 

Callograptus  salteri  Hall 

Plate 3,  figures  13-15 

Callograptus  salteri  Hall.  Canadian  Organic  Remains,  decade  2.  1865.  p.135, 

pi. 19,  fig.5-8 

Callograptus  salteri  Hopkinson  &  Lapworth.  Quar.  Jour.  Geol.  Soc.  1875. 
31:667,  pi. 34,  fig.10 

Callograptus  salteri  Gurley.  Jour.  Geol.  1896.  4:300 

Callograptus  salteri  Roemer  &  Freeh.  Lethaea  palaeozoica,  Bd  1.  1897. 

p.577 

Callograptus  salteri  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.554,  555,  565 

Description.  Rhabdosome  infundibuliform,  its  outer  margins  forming  an 
angle  of  40°-50°.  Branches  springing  from  a  thin,  hexuous  hydrorhiza 
■without  the  intervention  of  a  coarser  stem  ;  thin  (.5  mm  ad  max.),  numerous 
and  closely  arranged,  the  interspaces  being  less  than  the  width  of  the 
branches ;  flexuous  to  undulating,  bifurcating  at  irregular  intervals,  the 
resulting  branches  diverging  but  slightly  and  assuming  immediately  sub¬ 
parallel  directions;  rarely  connected  by  dissepiments.  Thecal  apertures 
circular,  little  projecting,  arranged  in  irregular  series,  numbering  14  to  18 
within  10  mm;  smaller  pores  observable  between  the  larger  apertures.  Often 
longitudinally  striated,  where  the  thecal  tubes  have  been  pressed  through  the 
periderm. 

Position  and  localities.  Fragments  of  this  species  are,  at  the  Deep 
kill,  common  on  slabs  of  graptolite  bed  2  (Tetragraptus  horizon),  but  have 
also  been  observed  on  those  of  graptolite  beds  1  and  5. 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


585 


Hall  states  that  his  originals  came  from  the  Quebec  group  at  Gros 
Maule  in  Canada.  As  we  also  find  Dichograptus  octobrac  hiatus, 

Tetragrap  tus  serra,  Didymograptus  con¬ 
st  r  i  c  t  u  s  and  Callograptus  e  1  e g a n  s  recorded 
from  that  locality,  the  Tetragraptus  horizon,  or  a  sub¬ 
horizon  close  to  it,  is  probably  exposed  there  ;  and  this 
species  occurs,  hence,  there  at  about  the  same  level  as 
here.  Gurley  has,  indeed,  observed  both  species,  C. 
s  a  1 1  e  r  i  and  C.  eles;ans,  only  in  the  “  Main  Point 
Levis  zone,”  which  is  the  Tetra¬ 
graptus  zone.  Lapworth  and  Ami 
have  not  noticed  this  form  among 
the  collections  of  the  Canadian  Geo- 
Hopkinson  and  Lapworth  identified 
the  Middle  Arenig  of  Whitesand 
Wales,  with  C.  salteri  and  C. 


Fig.18  Callograptus 
salteri  Hall.  A  fragment 
with  lateral  views  of  thecae. 
Deep  kill,  x  5.25 


logical  Survey, 
graptolites  from 
bay,  St  Davids, 
elegans. 

Prof.  H.  F.  Cleland  has  sent  me  a  quite  poorly 
preserved  graptolite  from  the  Beekmantown  beds  at 
Tribes  Hill,  in  the  Mohawk  valley,  which  appears  to  be 
identical  with  this  species. 

Hemarlcs.  While  fragments,  found  in  the  Deep  kill 
shales,  indicate  that  the  branches  attained  the  length  and 
width  observed  by  Hall  in  the  material  from  Gros  Maule, 
none  of  the  specimens  approach  the  robust  character  of 
the  specimens  figured  under  this  specific  designation  by 
Hopkinson  and  Lapworth  as  coming  from  the  Middle 
Arenig  of  Whitesand  bay  in  Wales. 

Hall  described  this  form  as  having  a  fiabelliform 
rhabdosome,  but  stated  under  the  generic  description 
that  it  is  possible  that  some  of  the  species  of  this  genus  may  have  grown 
in  funnel-shaped  rhabdosomes  as  Dictyonema.  The  specimen  of  C  .  s  a  1  - 


Fig.19  Callograptus 
salteri  Hall.  Enlargement 
of  portion  of  rhabdosome  to 
show  the  thecal  apertures. 
Deep  kill,  x  5.25 


586 


NEW  YORK  STATE  MUSEUM 


teri,  figured  here  on  plate  3,  figure  15,  appears  to  support  this  suggestion, 
at  least  in  regard  to  this  species. 

The  specimen  just  mentioned  is  further  remarkable  for  its  exhibiting  a 
distinct,  flexuous  nema  and  a  sicula.  Older  individuals  of  this  species 
possess  undoubtedly  a  robust  main  stem,  from  which  the  branches  spring 
and  which  terminates  proximally  in  a  spreading  fibrous  hydrorhiza,  as  it  has 
been  found  in  the  congeners  of  the  species,  notably  C.  elegans  and 
C.  radicans.1 

Callograptus  cf.  diffusus  Hall 

Plate  4,  figure  7 

Dendrograptus?  (Callograptus?)  diffusus  Hall.  Canadian  Organic 

Remains,  decade  2.  1865.  p.132,  pi.  18,  fig.  1-3 

Dendrograptus?  diffusus  Hopkinson  .&  Lapworth.  Quar.  Jour.  Geol.  Soc. 

1875.  31:664,  pl.36,  fig.7a,  7b 

Callograptus  diffusus  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 

p.570 

Description.  There  occur  in  the  shale  with  Phyllograptu  s 
t  y  p  u  s ,  at  the  base  of  the  horizon  with  Didy  mograptus  bifid  us, 
and  in  zone  3,  branches  of  a  dendroid  graptolite  which  possess  the 
characteristics  of  Dendrograptus?  (Callograptus?)  diffusus 
Hall,  viz  they  are  rather  strong  and  rigid,  frequently  bifurcating  and 
slightly  bending  at  the  bifurcations,  the  resulting  branchlets  strongly  diver¬ 
ging.  The  thecal  apertures,  which  number  about  16  in  10  mm,  are  arranged 
in  one,  somewhat  tortuous  series,  on  the  flattened  branch  and  circular  to  oval 
in  outline.  The  thecae  are  not  projecting. 

Position  and  localities.  Rare  in  zones  with  Didymograptus 
b  i  f  i  d  u  s  and  Diplograptus  dentatus  at  the  Deep  kill. 

1  By  Hopkinson,  Ann.  &  Mag.  Nat.  Hist.  ser.  4,  10:233,  pi. 10.  We  have,  therefore, 
probably  here  the  same  conditions  which  have  been  observed  by  the  writer  to  have 
existed  in  Dictyonema  flabelliforme  [p.595],  namely  suspension  by  a  thin 
filiform  nema  in  the  earlier  growth  stages  and  fixation  by  a  shorter  stout  stem  in  the  later 
stages. 


GRAPT0L1TES  OF  NEW  YORK,  PART  1 


587 


Remarks.  This  species  was  described  by  Hall  as  being  associated  at 
Point  Levis  with  Climacograptus  antenna  rius,  etc.,  i.  e.  with 
forms  of  the  horizon  of  Diplograptus  den  tat  us. 

Hopkinson  and  Lapworth  identified  with  Hall’s  species 
a  form  obtained  by  them  from  the  Lower  Arenig  of 
Road  Uchaf,  Ramsey  island,  Wales.  As  they  also 
obtained  Trigonograptus  ensiformis  at 
the  same  locality  it  apparently  occurs  in  Wales  at 
the  same  horizon  as  at  Quebec  and  at  the  Deep  kill, 
but  may,  as  indicated  by  the  occurrence  at  the  latter 
place,  appear  already  in  the  preceding  horizon. 

Hall  did  not  reach  any  definite  conclusion  as  to 
the  generic  position  of  the  species ;  Hopkinson  and 
Lapworth  referred  it  with  doubt  to  Dendrograptus, 
stating  that  “in  its  mode  of  branching  and  in  its  gen¬ 
eral  aspect,  it  is  a  true  Dendrograptus ;  but  its  thecae 
are  quite  unlike  those  of  the  typical  forms  of  this  genus, 
being  indicated  only  by  minute  indentations,  as  in  the 
genus  Callograptus.”  They  noticed  however  trans¬ 
versal  corrugations  or  joints  which  might  represent 
the  thecae  of  Dendrograptus  and  therefore  preferred  u^l/s0  gHailip  tEnS 

to  place  the  species  with  Dendrograptus.  In  the  tluT  thecal  apertures  Deep 
writer’s  specimens,  the  apertures  appear  distinctly  as 
appressed  circular  indentations,  without  traces  of  projecting  thecae. 

ptilograptus  Hall.  1865 

Hall  cited  the  following  as  the  generic  characters  of  this  genus 
[1865,  p.139]  :  “  Frond  plantlike,  rooted  ?  single  or  branching.  Branches  and 
branchlets  plumose,  the  pinnules  rising  alternately  on  opposite  sides  of  the 
branches;  celluliferous  on  one  face  only;  branches  cylindrical  or  flattened. 
Substance  corneous,  dense;  apparently  smooth  exteriorly,  or  corrugated  by 
compression,  or  during  fossilization.” 


588 


NEW  YORK  STATE  MUSEUM 


The  general  habit  of  the  types  of  this  genus,  due  notably  to  the 
plumose  arrangement  of  the  branches  on  a  principal  axis,  is,  as  Hall  has 
first  pointed  out,  extremely  suggestive  of  recent  hydrozoans,  such  as 
Plumularia  and  Aglaophenia,  but  this  similarity  is  evidently  only  the  result 
of  convergence.  Also  Freeh  [1897]  adduces  these  genera  for  comparison. 
The  latter  genus  has  one  nematocalyx  or  nematophore-bearing  cell 
in  front  and  one  on  either  side  of  each  hydrotheca.  It  is  with  these 
defensive  and  prehensile  individuals  that  Freeh  would  compare  those  con¬ 
sidered  as  gonangia  by  Wiman. 

The  group  of  forms  comprised  under  the  generic  term  Ptilograptus,  is 
a  very  small  one ;  for  the  exploitation  of  the  rich  homotaxial  faunas  of 
other  countries  has  increased  but  very  little  the  number  of  species  described 
by  Hall,  namely  by  a  form  only  doubtfully  referable  to  this  genus,  described 
by  Hopkinson  from  Wales.  We  add  here  a  third  species  to  the  two  known 
from  the  Quebec  shales  of  Point  Levis. 

Ptilograptus  plumosus  Hall 

Plate  4,  tig'll  re  14,  15 

Ptilograptus  plumosus  Hall.  Canadian  Organic  Remains,  decade  2,  1865. 
p.140,  pi. 21.  fig.l,  2?  3,  4 

Ptilograptus  plumosus  Billings.  Geol.  Sur.  of  Can.  Palaeozoic  Fossils.  1865. 
1 :  366,  375 

Ptilograptus  plumosus  Ami.  Geol.  Sur.  of  Can.  Report  1889.  ser.  2,  v.  3, 
pt2,  p.H7k 

Ptilograptus  plumosus  Hall.  N.  T.  State  Cab.  Nat.  Hist.  20th  An.  Rep’t. 
pl.4,  fig.16 

Ptilograptus  plumosus  Gurley.  Jour.  Geol.  1896.  4:  300 
Ptilograptus  plumosus  F.  Roemer  &  Freeh.  Lethaea  palaeozoica,  Bdl. 
1897.  p.579,  fig.151 

Ptilograptus  plumosus  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t. 
1902.  p.570 

Description.  Rhabdosome  consisting  of  an  irregularly  branching  princi¬ 
pal  stem  and  branches  provided  with  alternately  arranged  closely  set  branch- 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


589 


lets  (“  pinnules  ”  Hall)  which  give  to  the  colony  a  plumose  appearance. 
Stein  round,  smooth,  slightly  contracted  between  the  bases  of  the  pinnules; 
.3  mm  wide ;  total  length  unknown  ;  without  traces  of  thecal  apertures  in  the 
compressed  state.  Branchlets  slender,  filiform  (width  about  .13  mm),  fiexuous, 
closely  arranged,  the  branchlets  of  one  side  being  only  .6  mm  apart,  forming 
an  angle  of  40°  with  the  stem,  about  3 . 5  mm  long ;  showing,  in  the 
specimen  here  described,  no  thecae,  but  often  grooves  in  the  middle  as  if  com¬ 
posed  of  slender  tubes. 

Position  and  localities.  In  graptolite  bed  7  of  the  Deep  kill  section,  which 
is  a  bed  of  soft  shale  at  the  dam,  belonging  to  the  zone  with  Diplo- 
graptus  .dentatus.  It  is  also  frecpient  in  beds  containing  a  similar 
congeries  of  fossils  at  Mt  Moreno,  near  Hudson  N.  Y.  Hall  reports  that 
the  two  species  of  Ptilograptus,  which  he  described,  were  obtained  in  soft 
shale  associated  with  Loganograptus  1  o  g  a  n  i ,  Tetragraptus 
quadribrachiatus,  T  .  arcuatus,  T  .  b  i  g  s  b  y  i  and  others  in 
the  Quebec  group  of  Point  Levis.  This  association  would  indicate  the  zone 
with  Tetragraptus,  in  which  in  the  Deep  kill  section  no  specimens  of  this 
species  have  been  obtained.  Gurley  also  reports  the  form  as  only  occurring 
in  the  Main  Point  Levis  zone,  and  Ami  observed  it  in  material  from  Orleans 
island,  with  Loganograptus  logani  and  ClonOgraptus 
r  i  g  i  d  u  s .  As  it  is  very  rare  in  the  Deep  kill  bed,  but  more  common 
in  the  shale  of  Mt  Moreno,  which  contains  a  fauna  transitional  from  a  lower 
zone  to  that  with  Diplograptus  dentatus,  and  in  Canada  is  reported 
only  from  this  lower  zone,  it  would  seem  to  have  its  principal  development 
below  the  zone  with  Diplograptus  dentatus.  Billings  found  it 
among  the  graptolites  from  Division  P  at  the  Cowhead,  Newfoundland. 

Remarks.  Hall  supposed  the  fine  transversal  markings  which  also 
appear  on  parts  of  the  specimen  figured  here,  to  be  thecal  apertures 
and  concluded  that  the  latter  were  arranged  on  one  face  of  the 
branchlets. 


590 


NEW  YORK  STATE  MUSEUM 


Ptilograptus  geinitzianus  Hall 

Plate  4,  figrure  16 

Ptilograptus  geinitzianus  Hall.  Canadian  Organic  Remains,  decade  2. 

1865.  p.14-0,  pl.21,  fig.5-8 

Ftilograptus  geinitzianus  Gurley.  Jour.  Geol.  1896.  4:300 
Ptilograptus  geinitzianus  F.  Roemer  &  Freeh.  Letliaea  palaeozoica,  Bdl. 

1897.  p.580 

Description.  This  species  is  represented  by  a  few  somewhat  frag¬ 
mentary  specimens  which  consist  of  a  branch  and  the  bases  of  the 
branchlets.  One  branch,  which  has  a  length  of  21  mm,  is  broad  (about  .8  mm 
wide),  little  tapering  and  consisting  of  a  thick  chitinous  test.  The  branch- 
lets  are  closely  alternating  on  opposite  sides  of  the  branch  (those  of  the 
same  side  are  1 . 5  mm  apart),  diverge  from  the  branch  at  an  angle  of  about 
50°  and  have  a  basal  width  of  .  5  mm.  They  are  appressed  to  the  stem 
for  a  short  distance.  No  traces  of  thecal  apertures  are  observable  on 
them ;  the  only  indication  of  such  an  aperture  being  visible  on  the  stem, 
near  the  base  of  a  branch. 

Position  and  localities.  The  specimens  were  found  at  the  Deep  kill  in 
graptolite  bed  3,  the  lowest  bed  of  the  zone  with  Didymograptus 
b  i  f  i  d  u  s  . 

Hall  records  it  as  occurring  in  the  Quebec  shales  at  Point  Levis  with¬ 
out  mentioning  its  associates,  but  Gurley  observed  it  in  the  Main  Point 
Levis  zone.  It  seems,  hence,  at  the  Deep  kill  to  pass  beyond  its  range  in 
the  Quebec  region. 

Demarks.  Hall’s  more  complete  specimens,  which  were  obtained  in 
the  Quebec  shale  of  Point  Levis,  show  that  the  rhabdosome  is  irregularly 
branching.  This  species  is  said  to  differ  from  P .  p  1  u  m  o  s  u  s  by  its 
stronger  and  coarser  habit,  its  more  frequent  and  irregular  branching,  its 
broad,  flattened  branches  and  the  broader  branchlets.  It  is  doubtful 
whether  the  thecal  apertures  are  as  regularly  distributed  on  one  face  of 
the  branchlets  as  represented  in  the  original  drawings  of  the  species. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


591 


Ptilograptus  tenuissimus  sp.  nov. 

Plate  4,  flg-uro  13 

There  has  been  found  in  graptolite  bed  3  of  the  Deep  kill  section 
an  extremely  delicate  rhabdosome,  in  fact,  so  tenuous  that,  notwithstand¬ 
ing  its  considerable  length,  it  is  only  with  difficulty  visible  to  the  naked 
eye. 

Description.  The  specimen  consists  of  a  single  principal  stem  or  branch 
which  is  28.6  mm  long,  but  not  more  than  .  1  mm  wide  in  its  thickest  part 
and  very  gradually  tapering  toward  the  distal  end.  The  branchlets  are 
arranged  bipinnately,  extremely  thin  (not  more  than  .  03  mm  thick  near  their 
base),  filiform,  reaching  a  length  of  8 . 2  mm.  Those  of  one  side  are  about 
2.2mm  apart  and  diverge  at  an  angle  of  about  40°  from  the  stem.  No 
traces  of  thecae  or  thecal  apertures  are  noticeable  anywhere  on  the 
branches. 

Position  and  localities.  Graptolite  bed  3  (zone  with  Didymo- 
graptus  bifidus)  at  the  Deep  kill. 

Remarks.  This  form  is  easily  distinguished  from  P.  plumosusby 
the  much  longer  and  slenderer  stem  and  branchlets  and  the  greater  distance 
between  the  bases  of  the  latter,  which  is  about  four  times  as  great  as  in 
the  specimen  of  P.  plumosus  figured  here  and  tAvice  as  great  as  in 
the  type  specimen  of  that  species,  which,  extending  to  a  more  proximal 
part  of  the  rhabdosome,  has  the  branches  a  little  farther  apart. 

This  species  bears  some  similarity  to  the  form  described  by  Hall  as 
Thamnograptus  anna  from  the  same  horizon,  but  differs  by  its 
straight,  not  zigzagged  principal  branch  and  the  greater  inclination  of  the 
branchlets. 

DICTYONEMA  Hall.  1852 

The  generic  term  Dictyonema  was  proposed  by  Hall  in  Palaeontology 
of  New  York,  volume  2,  for  a  group  of  fossils  which  hitherto  had  been 
referred  to  such  widely  different  groups  as  the  gorgonias,  bryozoans  and  the 
algae.  It  is  to  Hall’s  credit  to  have  first  observed  the  thecae  and  clearly 


592 


NEW  YORK  STATE  MUSEUM 


recognized  the  graptolite  nature  of  Dictyonema  in  spite  of  its  different  habit 
[1865,  p.136]. 

Since  Hall’s  brief  description  of  the  genus,  its  characters  have  been 
repeatedly  discussed,  specially  by  Nicholson,  Dames,  Brogger,  Tullberg  and 
Matthew.  These  observers  have  established  the  fact  of  the  presence  of  a 
sicula  in  several  forms,  as  in  D.  flabelliforme,  at  the 
initial  part  of  the  rhabdosome,  and  the  basketlike  or  conical 
shape  of  the  latter,  as  well  as  the  position  of  the  thecae  on 
the  inside  of  the  basket. 

But  the  complicated  structure  of  the  branches  was 
not  suspected  till  Holm  in  1890  described  in  D.  cervi- 
corne,  from  the  Upper  Siluric  in  Gotland,  appendages 
to  the  thecae,  shaped  like  birds  nests  [text  fig.21] 
which  he  thought  might  possibl}r  be  gonangia.  Wiman 
succeeded  in  isolating  the  rhabdosome  and  obtain¬ 
ing  thin  sections,  by  means  of  which  [1895  and  1896]  he  has  demon¬ 
strated  that  the  branch  consists  of  three  different  kinds  of  individuals 
[see  sections,  text  figure  23  copied  from  Wiman  |.  These  he  denotes  as 
nourishing  individuals  (his  thecae,  t,  tx,  ta  in  sections),  since  they  doubtless 
correspond  to  the  thecae  in  the  Graptoloidea,  budding  individuals  (k,  k,, 
k2  etc.)  and  sexual  individuals  or  gonangia  (g,  gb  g3  etc.).  The  budding 
individuals  [see  section  6],  which  do  not  open  outward,  produce  three 
individuals  by  gemmation,  one  of  which  is  again  a  budding  individual, 
while  the  second  is  a  theca  and  the  third  a  gonangium.  All  the  indi¬ 
viduals  are,  according  to  Wiman,  formed  in  this  way.  Freeh  [1897,  p.571  | 
expresses  the  view  that  the  so  called  gonangia  of  Holm  and  Wiman  are 
comparable  to  the  nematocalyces  of  the  Hydrozoa,  by  adding  behind 
gonangia  ( rectius  Nematophoren -).1 

1Wiman  has  in  a  later  paper  [1900,  p.  188]  pointed  out  in  defense  of  his  view  that 
the  nematocalyces  occur  in  pairs,  while  but  one  gonangium  is  found  associated  with  a 
theca,  and  further,  that  the  nematophores,  as  defensive  polyps,  have  as  a  rule  an  exposed 
position  while  the  organs  considered  by  him  as  gonangia  are  found  in  protected  positions. 


Fig.21  Dictyone¬ 
ma  cervicorne 
Holm.  Shows  the 
uppermost  thecae 
of  two  adjoining 
branches,  with  their 
forklike  processes 
and  nestlike  by- 
thecae  or  gonangia. 
xl2.  (Copy  from 
Holm) 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


593 


While  our  material,  which  is  preserved  in  clay  slates,  seems  unfit  to 
allow  any  such  method  of  investigation  as  Wiman  employed,  it  will  at 
least  sometimes  permit  the  observation  of  the  composite  nature  of  the 
branches,  as  in  the  specimen  reproduced  in  text  figure  28.  In  this,  some 
parts  have  been  slightly  infiltrated  with  pyrite,  which  has  brought  out 
plastically  the  narrow  tubes,  running  alongside  of  the  thecae  and  presum¬ 
ably  representing  the  “gonangia”  and  “budding  individuals.”  The  absence 
of  any  axis  is  also  distinctly  shown 
in  this  specimen.  The  numerous 
large  pores  appearing  on  the  sur¬ 
face  of  certain  compressed  branches 
are  apparently  the  apertures  of  the 
thecae. 

The  question  of  the  mode  of  life  of  the  Dictyonemas  has  been  mooted 
repeatedly.  Hall  gave  in  Palaeontology  of  New  York,  volume  2,  plate  40, 
figure  1,  a  figure  [copied  1865,  p.12,  fig.10],  which  appears  to  indicate  a 
central  root.  This  drawing  has  been  cited  frequently  as  proof  that  the 
rhabdosome  of  Dictyonema  was  sessile.  Hall,  himself,  does  not  mention 
the  presence  of  such  a  root  in  either  the  description  of  the  species  or  the 
definition  of  the  genus.  He  states,  on  page  39  of  the  last  mentioned  work, 
that  “  the  Dictyonemas  of  the  Niagara,  Upper  Helderberg  and  Hamilton 
groups  do  occur  in  strata  which  contain  large  numbers  of  other  fossils, 
but  we  have  no  evidence  of  their  having  been  attached.  It  is  only  from 
their  general  form  therefore  and  from  their  analogy  with  other  bodies, 
that  we  infer  that  these  genera  may  have  been  attached  to  the  sea 
bottom  or  to  some  objects  during  their  growth.”  Nicholson  [1872,  p.l 2 J 
doubted  the  presence  of  the  root;  Brogger  [1882,  p.32]  reports  that  he 
found  specimens  of  D.  flabelliforme  with  siculae,  the  free  end 
of  which  is  pointed,  and  that  “  that  species  certainly  was  not 
attached,  which  in  all  probability  may  be  right  for  the  genus  in 
general.” 


Fig.22  Dictyonema  rarum  'VViman.  Frag¬ 
ment  of  a  branch  etched  out  of  flint.  Shows  the 
thecae  and  the  apertures  of  the  gonangia.  xli. 
(Copy  from  Wimnn) 


NEW  YORK  STATE  MUSEUM 


594 

Matthew,  who  had  a  large  collection  of  D.flabelliforme  from 
the  St  John  basin  for  investigation,  considered  it  as  having  had  a  floating 
mode  of  existence  [1891,  9:85],  When,  later,  G.  van  Ingen  collected  some 
specimens  of  the  same  species  for  him,  which  had  short  rootlets  [figured 
1895,  pl.49,  fig.l  and  2],  he  remarked  that  “it  might  appear  from  such 
examples  as  these,  that  it  would  be  possible  to  show  the  existence  of  a 
sedentary  variety  or  stage  in  this  species ;  still,  it  does  not  seem  that  this 
condition  of  the  rliabdosome  is  at  all  frequent,  for  among  scores  that  have 


Fig.23  Dictyonema  rarura  Wiman.  Series  of  thin  sections.  t= thecae 
or  nourishing  individuals;  g  =  gonangia;  k  =  buddingindividuals.  FromLower 
Siluric  flint-boulders  of  Gotland.  x53.  (Copy  from  Wiman) 


been  examined  since  these  were  found,  none  with  roots  have  been  detected.” 
It  is  further  suggested  that  these  processes  may  have  had  some  other  office 
than  that  of  anchoring  the  rliabdosome  at  the  bottom,  and  that 
they  are  too  short  to  afford  more  than  a  very  feeble  foothold  at  the 
surface  of  the  soft  ooze. 

Wiman’s  investigations  have  made  us  well  acquainted  with  the  proximal 
end  of  at  least  one  species,  D.  caver  no  sum.  This  [fig.24,  25J 
shows  a  basal  disk,  provided  with  radial  ribs,  which  extend  into  a  kind  of 
network  that  would  seem  to  have  been  well  adapted  to  fixation  on  soft 
ooze.  Wiman  came  indeed  to  the  conclusion  that  the  Dictyonemas,  like  all 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


*  595 


graptolites,  were  denizens  of  the  deeper  littoral  regions,  where  they  formed 
continuous  fields. 

Lap  worth  [J„  Walther,  1897,  p.250]  reports  that  in  some  forms  of 
Dictyonema  not  only  does  the  rhabdosome  begin  with  a  sicula,  but  this 
sicula  is  provided  with  a  nema,  as  in  the  Rhabdophora,  and  that  this  nema 
persisted  as  a  perpetual  means  of  attachment  to  foreign 
bodies  or  to  a  central  network  of  filaments  (hydror- 
hiza)  throughout  the  whole  life  of  the  rhabdosome. 

All  specimens  of  D .  flabelliforme,  obtained 
at  Schaghticoke  and  in  the  region  of  Granville,  which 
retained  more  than  the  sicula,  showed  this  to  extend 
into  a  fine  nema  [see  the  large  specimen  figured  on  pl.l, 
fig.20].  All  the  young  stages,  of  which  great  numbers 
were  obtained,  possessed  long  nemas,  often  extrava¬ 
gantly  long  as  in  the  specimen  represented  on  the  same 
plate,  figure  1,  where  the  nema  is  nearly  20  times  as 
long  as  the  sicula.  In  a  few  cases  [pl.l,  fig.  10]  this 
nema  seems  to  end  in  a  rather  large  subcircular,  very  thin,  chitinous  disk, 
which  does  not  show  any  structural  features.  The  nema  has  been  slightly 
flexible,  as  its  gentle  curves  prove,  and  it  would  appear  to  be  hardly  strong 
enough  to  have  supported  the  young  colonies,  not  to  speak  of  the  full  grown 
specimens.  I  have,  therefore,  represented  all  these  specimens  as  suspended. 

In  assuming  that  the  rhabdosomes  of  D.  flabelliforme  were  sus¬ 
pended,  I  am  however  well  aware  that  there  exist  facts  which  apparently 
combat  such  a  conclusion.  One  of  these  is,  in  my  opinion,  the  opening  of  the 
thecae  toward  the  inside  of  the  basketlike  rhabdosome.  As  the  zooids  were, 
no  doubt,  provided  with  some  form  of  prehensile  organs  by  which  they 
caught  small  organisms,  it  would  at  first  glance  seem  that  in  a  suspended 
colony  of  this  kind  they  were  in  a  very  unfavorable  condition  and  shut  out 
from  their  food  supply.  But  it  is  to  be  considered  that  they  may  have  set 
up,  by  the  action  of  their  arms,  a  circulation  which  carried  organisms  and 
food  particles  into  the  cone,  where  escape  would  be  impossible ;  and  it  is  also 


Fig.24  Dictyonema  caver, 
no  sum  Wiman.  Proximal  end 
of  rhabdosome,  with  “adhesive 
disk.”  xlO  (Copy  from  Wiman) 


596 


NEW  YORK  STATE  MUSEUM 


quite  likely  that  a  suspended  bell  of  this  kind  would  have  been  voluntarily 
sought  by  numerous  small  animals  as  shelter,  as  some  contrivances  of  preying 
water  plants  are  sought  by  small  crustaceans. 

While,  however,  the  specimens  of  D.  flabelliforme  from  Schaghti- 
coke  are  provided  with  thin,  long  nernas,  Matthew  has  figured  [1892,  pl.49] 
two  representatives  of  that  species  with  short,  broad  rootlets.  There  are  then 
three  possibilities : 

1  The  presence  of  the  nema  in  the  Schaghticoke  specimens  and  that  of 
the  short,  rootlike  disks  in  the  St  John  specimens  may  constitute  specific  or 
varietal  differences,  indicative  of  an  entirely  different  mode  of  existence.  This 
seems  to  us  very  improbable,  as  it  is  not  supported  by  any  other  differences 
observable. 

2  The  thin  disk,  observed  in  some  young  stages  at  the  end  of  the  nema, 
may  grow  out  into  the  stouter  disk  or  bundle  of  rootlets. 

3  The  adhesive  disk  of  mature  specimens  may  be  a  new  formation,  suc¬ 
ceeding  normally  that  of  the  nema. 

In  case  2  it  is  difficult  to  understand  how  the  disk  at  the  end  of  the 
nema  could  have  wandered  along  the  long  nema  to  the  proximal  end  of  the 
sicula ;  we  believe,  therefore,  that  the  disk  or  root  of  mature  forms  was  a 
structure  developed  toward  the  mature  age  of  the  colony.  This  inference 
seems  also  to  be  supported  by  Wiman’s  observation,  that  in  Discograptus 
schmidti,  another  dendroid,  the  bases  of  the  branches  grow  directly  out  of 
this  disk  or  are  embedded  in  it,  that  hence  it  did  not  form  till  after  the  first 
bifurcation  had  taken  place ;  and  that  in  D .  cavernosum  apparently  it 
incloses  the  sicula.  Moreover,  we  have  observed  and  will  demonstrate  in  this 
paper  that  the  “  central  disk  ”  of  the  Dichograptidae,  which  is  expanded 
between  the  branches,  is  a  secondary  formation,  independent  of  the  primary 
disk  from  which  the  nema  of  the  sicula  was  suspended.  It  is  proper  to 
conclude  that  we  have  in  the  Dictyonemas  a  case  entirely  homologous  to  that 
observed  in  the  Dichograptidae. 

Lapworth  appears  to  have  made  similar  observations,  for  he  states 
[loc.  cit.  p.253]  that  certain  forms  of  Dictyonenm  have  a  short  stem,  others  a 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


597 


membrane  of  attachment,  still  others  a  so  called  disk  of  fixation,  and  others, 
finally,  are  provided  with  a  delicate  filament  of  attachment,  which  (certainly 
in  the  first  growth  stages  of  the  rhabdosome)  was  as  long  and  delicate  as  the 
nema  of  a  young  graptoloid.  A  comparison  of  the  specimens  of  D  .  flabel- 
liforme,  from  Schaghticoke  [pl.l]  and  St 
Johns,  shows  that  these  different  forms  of 
attachment  may  even  occur  in  the  same 
species.  Lapworth  is,  in  the  writer’s  opinion, 
therefore  justified  in  holding  [ibid,  p.254] 
that,  whether  the  nema  developed  into  a 
stem,  a  disk,  a  membrane  or  a  filament,  is  per¬ 
haps  not  so  essential  as  it  might  appear  at 
first  glance,  these  formations  all  being  only 
variations  of  the  nema.  This  view  is  at  vari¬ 
ance  with  the  suggestion  of  Holm  that  the 
basal  part  of  Dictyonema  might  supply  the 
means  of  a  natural  subdivision  of  the  genus, 
which  have  not  yet  been  found  in  the  char¬ 
acters  of  the  rhabdosome. 

From  the  appearance  of  the  delicate, 
flexible  nema  Lapworth  also  concluded 
that  Dictyonema  must  have  been  suspended 

like  a  bell  at  the  end  of  a  rope,  as  he  supposes,  from  seaweeds. 

Wiman  published  in  1897  [p.352]  an  investigation  of  the  structure  of 
some  graptolites  of  Gotland.  Among  the  latter  he  had  a  specimen  of 
D.  caver  nosum  which  shows  two  colonies  apparently  fastened  to  the 
same  stolon  [ see  text  fig.  25],  and,  as  he  concludes  from  his  sections,  also  pro¬ 
duced  from  the  same  hollow  stolon.  This  discovery  would,  if  Wiman  observed 
correctly,  introduce  an  entirely  new  mode  of  propagation  of  Dictyonema. 

The  question  suggests  itself  at  once,  whether  the  long  nema  observed 
in  the  young  of  D.  flabelliforme  was  not  such  a  stolon.  Such  a  view 
is,  however,  controverted  by  the  fact  that  the  nema  begins  with  an  adhesive 


Fig-.  25 


Dictyonema  cavernosum 
Proximal  end,  showing  stolons.  xlO 
(Copy  from  Wiman) 


Wiman. 


598 


NEW  YORK  STATE  MUSEUM 


disk  and  ends  in  a  distinct  sicula  from  which  the  rhabdosome  grows,  while 
in  D.  caver nosnm  a  stem  containing  a  theca  and  a  budding  individual 
appears  to  grow  directly  from  the  stolon. 

As  Wiman  has  described  similar  stolonlike  filaments  as  extending  from 
the  basal  disks  of  other  Dictyonemas  and  the  rootlets  of  D .  flabelli- 
f  o  r  m  e  figured  by  Matthew  are  also  distinctly  dividing  into  filaments,  it  can 
be  inferred  that  the  rhabdosome  of  D.  flabelliforme  was  up  to  maturity 
suspended  by  a  thin  nema  from  an  adhesive  disk  [pl.l,  fig.20],  that  it  then 
however  secured — perhaps  not  always — a  firmer  attachment  by  a  secondary 
disk  or  a  hydrorhiza,  which  lay  close  to  its  sicula,  as  is  indicated  by  Matthew’s 
specimens.  If  this  disk  then  produced  stolons  from  which  grew  new  rhabdo- 
somes,  we  would  have  rhabdosomes  of  two  orders,  those  of  the  first  order, 
produced  directly  from  the  sicula,  and  those  of  the  second  order,  which 
budded  from  the  stolons  of  those  of  the  first  order,  or  a  composition  of  the 
entire  colony  somewhat  analogous,  but  different  in  origin,  to  that  found  in 
Diplograptus. 

Holm  [1890,  p.4f]  has  discussed  the  state  of  our  knowledge  of  the  genus 
and  specially  of  its  species  and  shown  that  most  of  them  have  been  or  had  to 
be  founded  on  insufficient  material.  In  most  cases  nothing  but  portions  of  the 
rhabdosome  have  been  described  without  knowledge  of  the  thecae.  A  table 
given  in  the  cited  work  shows  that,  of  the  25  species  known  at  that 
time,  the  whole  rhabdosome  and  the  thecae  in  their  profile  view  were  known 
in  the  case  of  but  four.  Most  species  are,  therefore,  founded  only  on  the 
thickness  of  the  branches  and  dissepiments,  the  number  of  branches,  the 
form  and  dimensions  of  the  meshes.  He  suspects,  therefore,  that  not  all 
forms  described  as  Dictyonema  belong  to  that  genus,  specially  as  it,  in 
striking  contrast  to  all  other  genera  of  graptolites,  which  are  very  short¬ 
lived,  is  the  first  appearing  and  the  last  disappearing  genus,  and  thus 
would  seem  to  range  from  the  Upper  Cambric  into  the  Middle  Devonic 
Hamilton  beds.  The  discovery  of  specimens  embedded  in  limestone  will 
certainly  furnish  in  time  the  characters  necessary  for  a  division  of  the  genus. 
In  fact  Wiman  [1900,  p.!89j  has  proposed  to  restrict  the  genus  to  forms 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


599 


with  simple  branches  and  dissepiments  (consisting  of  but  one  series  of 
individuals)  and  has  made  a  species  with  compound  branches,  originally 
described  by  him  as  a  Dictyonema  (  D .  tuberosum)  the  type  of  a  new 
genus,  Reticulograptus.  It  seems  doubtful  to  me  however  whether  the  genus 
Dictyonema  could  be  properly  based  on  new  species  without  regard  to  the 
original  genotype,  which  is  a  Niagaran  form. 

It  appears  also  that  gradually  the  definition  of  the  genus  has  been 
extended  till  it  includes  forms  which  can  not  be  considered  as  falling  within 
the  scope  of  Hall’s  original  definition.  Therefore  the  subgeneric  term  Desmo- 
graptus  was  proposed  by  Hopkinson  [1875,  p.668]  in  recognition  of  the  fact 
that  in  some  species  the  meshes  are  not  formed  by  parallel  branches  and 
straight  dissepiments  but  by  the  coalescence  of  the  undulating  branches. 
Gurley  argues  that  this  group  is  entitled  to  full  generic  rank.  As  other 
species  (Desmograptus  devonicus  Gurley  and  D.  intricat  us 
Ruedemann)  are  clearly  proved  to  possess  the  same  distinctive  character,  the 
latter  will  serve  to  establish  an  easily  recognized  division  of  the  hitherto 
undivided  large  genus  Dictyonema. 

Hopkinson  proposed  also  [ibid,  p.667]  the  alteration  of  the  name  Dictyo¬ 
nema  into  Dictyograptus,  on  the  ground  that  the  former  is  an  old  established 
name  for  a  genus  of  plants.  This  proposition  has  led  to  an  interesting  argu¬ 
ment  between  Moberg  and  Tornquist  [1894].  As  we  see  no  possible  danger 
of  confusion  arising  by  the  retention  of  the  old  name,  we  have  continued 
to  use  it. 

Dictyonema  flabelliforme  Eichwald  (sp.) 

Plate  1,  figure  1-22 

Gorgonia  flabelliformis  Eichwald.  Sil.  Schiclit.  Syst.  in  Esthland.  1840.  p  207 
Gorgonia  flabelliformis  Eichwald.  Urwelt  Russl.  H.H.  1842.  p.45,  tab.l,  fig.6 
Eenestella  flabelliformis  Eichwald.  Beitriige  z.  Geol.  u.  Palaeont.  Russl. 

Bui.  d.  1.  soc.  d.  natur.  d.  Moscou.  1854.  no.l,  p.6;  1855.  no.4,  p.453 
Phyllograpta  sp.  Aug.  Pal.  suec.  1854.  p.4 

Graptopora  socialis  Salter.  Am.  Ass’n  Proc.  1857.  11:65 

Dictyonema  hisingeri  Goppert.  Ub.  d.  foss.  Flora  d.  sil.  dev.  und  unt. 

Kohlenform.  etc.  1860.  Act.  T.eop.  27:31,  tab.36,  f.  2c,  4-11;  tab.45,  fig.3,  4 


600 


NEW  YORK  STATE  MUSEUM 


Rhabdinopora  f  labellif  or  mi  s  Eicliwald.  Leth.  ross.  1860.  p.369 
Non  Dictyonema  f  label!  if  or  me  F.  Roemer.  Foss.  Fauna  v.  Sadewitz. 
1861.  p. 32,  pi. 5,  fig.4  (  =  D  .  sadewitzense  F.  Roemer) 

O 

Dictyonema  flabelliformis  Tomquist.  Lunds  Univ.  Arsskrift.  1865.  t.2, 
III,  22,  pl.l,  fig.14 

Dictyonema  norvegicum  Kjerulf.  Y eiviser  etc.  1865.  p.l,  2,  fig.1-3 
Dictyonema  graptolithinum  Kjerulf.  Ibid,  p.l,  3,  fig.4,  5 
Dictyonema  social  e  Salter.  Geol.  Sur.  Mem.  1866.  3:331,  pl.4,  fig.l 
Dictyonema  flabelliforme  Malaise.  Doc.  pal.  rel.  au  Terr.  Camb. 
de  l’Ardenne.  1881 

Dictyograptus  flabelliformis  Brogger.  Die  sil.  Etagen  2  and  3,  etc.  1882. 
p.30,  pi. 12,  fig.17-19 

Dictyonema  flabelliforme  Tullberg.  Bib.  till  K.  Svenska  Yet.-Akad.  Handl. 
1882.  Bd6,  no. 13.  1880-82 

Dictyonema  flabelliforme  Schmidt.  Quar.  Jour.  Geol.  Soc.  1882.  p.517 
Dictyonema  flabelliforme  Dawson.  Rep’t  Peter  Redpath  Mus.  McGill 
Univ.  1883.  p.16 

Dictyon  e  m  a  s  o  c  i  a  1  e  Lapwortli.  Roy.  Soc.  Can.  Proc.  and  Trans.  1887. 
4:168 

Dictyonema  flabelliforme  Moberg.  Sver.  Geol.  Und.  Afh.  och  npps. 
1890.  ser.C,  no.109,  p.3 

Dictyonema  flabelliforme  Matthew.  Roy.  Soc.  Can.  Proc.  and  Trans. 
1892.  9:34 

Dictyonema  flabelliforme  Wiman.  Geol.  Inst.  Upsala.  Bui.  1895.  no.4, 
v.2,  pt2,  p.55,  pi. 10,  %.13,  14 

Dictyonema  flabelliforme  Matthew.  N.  Y.  Acad.  Sci.  Trans.  1895. 
14:262,  pi. 49,  fig.l,  2 

Dictyonema  flabelliforme  Gurley.  Jour.  Geol.  1896.  4:292 
Bryograptus?  m  u  1  t  i  r  amosus  Gurley,  Ibid,  p.64 

Dictyonema  flabelliforme  Freeh.  Lethaea  palaeozoica.  1897.  1:572, 
pl.2,  fig.3a,  3b 

Dictyonema  flabelliforme  Dale.  U.  S.  Geol.  Sur.  19th  An.  Rep’t.  1899. 
pt3,  p.l 85 

Dictyonema  flabelliforme  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t. 
1903.  p.936 

Description.  Rhabdosome  a  rapidly  expanding  cone,  rate  of  expansion 
sucli  that  in  tlie  compressed  state  the  diameter  at  any  place  is  about 
equal  to  the  distance  of  its  center  from  the  apex  of  the  cone  ;  cone  attain- 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


601 


ing  a  length  of  5  cm  and  more.1  Suspended  from  a  thin,  long  nema  [ see 
description  of  genus  for  discussion  of  mode  of  fixation  and  existence  of 
D .  flabelliforme]. 

Branches  about  .  4  mm  wide,  subparallel,  rigid,  bifurcating  at  long 
intervals,  distant  a  little  more  than  1mm  (about  18  in  20  mm),  con. 
nected  by  dissepiments,  which  are  about  half  as  thick  as  the  branches 
and  separated  by  intervals  twice  as  wide  as  the  latter, 
thus  forming  meshes  with  the  branches  which  are  about 
twice  as  long  as  wide.  Thecae  (nourishing  individuals) 
disposed  on  the  inside  of  the  branches,  forming  short, 
acutely  pointed  or  mucronate  processes,  numbering  about 
14  to  16  in  10  mm.  Smaller  apertures  noticeable  along 
the  lateral  sides  of  the  branches. 

Position  and  localities.  Upper  Cambric  graptolite 
shale  of  Schaghticoke,  Rensselaer  co.  N.  Y.,  in  association 
with  Staurograptus  dichotomus  Emmons 
(=C  1  o  n  o  g  r  a  p  t  u  s  proximatus  Matthew).  Very 
frequent  also  in  black  slate  at  various  localities  in  the 
slate  belt  in  Washington  county,  N.  Y.,  specially  about 
Granville,  as  at  North  Granville,  Hillsdale,  on  Hatch 
hill,  on  Marion  hill  near  South  Hartford,  in  several  of 
which  localities  it  is  also  found  associated  with  Staurograptus 
dichotomus.  Near  South  Hartford  it  occurs  also  in  a  dirty  brownish 
weathering  limestone.  There  is  little  doubt  that  its  distribution  extends 
northward  through  Vermont.  I  find  for  instance  young  specimens  in  a 
shale  collected  by  T.  N.  Dale  on  Hamilton  hill  near  Fair  Haven  in  southern 
Vermont. 

The  wide  distribution  of  this  important  index  fossil  of  the  closing 
period  of  the  Cambric  in  Canada  and  Europe  has  been  discussed  in  detail 
by  the  present  writer  [1903].  In  Canada  it  has  been  reported  by  Dawson 

1Mr  van  Ingen  informs  me  that  he  collected,  in  the  St  John  basin,  specimens 
having  a  length  of  10  to  12  inches. 


Fig.  26  D  i  c  t  y  o  n  e  m  a 
flabelliforme  Eich- 
wald  (sp.)  Fragment  of 
branch  showing  lateral 
view  of  thecae  and  aper¬ 
tures  of  flanking  tubes 
(“gonangia”).  Schaghti¬ 
coke.  x5 


602 


NEW  YORK  STATE  MUSEUM 


and  Lapworth  from  the  region  along  the  south  bank  of  the  St  Lawrence 
from  the  Matane  river  eastward  to  Gaspe ;  further,  from  Cape  Breton  island 
and  the  St  John  basin  by  Matthew.  In  Europe  D.  flabelliforme 
marks  the  last  horizon  of  the  Cambric  in  Esthonia,  Russia;  in  the  black 
Alum  shales  of  East  and  West  Gothland,  and  of  Scania;  in  the  neigh¬ 
borhood  of  Christiania,  on  Bornholm ;  in  the  Lower  Tremadoc  of  north  and 

south  Wales,  and  in  the  county  Meath  in  Ireland ;  and  at 
several  localities  in  Belgium.  This  form  is  at  once  the 
longest  known  and  thus  far  geologically  oldest  species  of 
the  genus  and  has  the  widest  distribution  of  the  species  of 
Dictyonema.  In  distinction  from  the  others,  it  appears 
in  tbe  horizon,  characterized  by  it,  in  immense  numbers, 
mostly  to  the  exclusion  of  other  forms ;  and  the  graceful 
suspended  bells  have  therefore,  for  a  short  time,  swarmed 
over  a  very  vast  tract  of  the  northern  Cambric  ocean,  in 
immense  multitudes. 

Development  The  slates  at  Schaghticoke  have 

showing  dissepiment  and  ,  _  __  _  _ 

t£belurschaghticokekix5  furnished  a  complete  series  of  growth  stages  of  D  .  fla¬ 
belliforme  [pl.l,  fig.1-20],  the  first  one  yet  made 
known  of  this  genus.  This  permits  the  elucidation  of  a  few  facts. 

The  youngest  stage  observed  is  a  relatively  short  and  stout  sicula, 

attached  to  an  extremely  long  and  slender  nema  [fig.  1].  By  means  of  this 

nema  it  was  probably  suspended  from  the  beginning  from  a  subcircular, 
thinly  chitinous  organ,  which  is  rarely  observed  [fig.  10]  and  which 

may  have  been  either  a  float  or  a  membrane  of  adhesion  to  seaweeds  etc. 

When  the  sicula  has  grown  beyond  the  length  attained  in  figure  1,  a 
lateral  bud  appears  [fig.2-4]  which,  after  a  short  adherence  to  the  sicula, 
diverges  under  a  very  large  angle  (about  75°).  This  theca  almost 

immediately  divides  [fig.5,  6]  as  it  appears,  both  resulting  thecae  diverging 
about  equally.  Next  a  third  theca  is  noticed  [fig.6,  7],  all  three  being  so 
arranged  as  to  form  a  tripod,  and  a  fourth  theca,  apparently  branching 
from  tbe  third,  quickly  completes  the  original  group  of  four  thecae 


Fig.27  Dictyonema 
flabelliforme  Eieh- 
wald  (sp.)  Fragment 
showing  dissepiment  and 
res  of  flank' 
Schaghticoke. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


603 


[  fig. 8,  9],  The  formation  of  the  four  primary  thecae  takes  place  in  such 
a  narrow  space  —  as  it  would  appear,  along  a  continuation  of  the  sicula  — 
that,  where  young  colonies  have  become  compressed  vertically  (as  in  figures 
14  and  15)  usually  four  branches  diverge  from  the  center.  These  continue 
to  bifurcate  quite  rapidly,  but  in  unequal  distances  [fig.  15— 17].  Sometimes 
they  divide  again  so  early  that  a  whole  bundle  of  branches  seems  to  pro¬ 
ceed  directly  from  the  distal  end  of  the  sicula  [fig.16].  Where  a  rhabdo- 
some,  which  has  developed  a  little  further,  has  been  compressed  obliquely, 
so  as  to  expose  the  base  [fig.  19],  one  sees  a  central  cross,  each  of  the  arms 
of  which  divides  into  a  bush.  The  dissepiments  or  transverse  connecting 
filaments  may  appear  already  on  the  branches  of  the  second  order  [fig.  13], 
but  they  do  not  become  common  enough  to  form  a  network  till  the  branches 
of  the  third  order  have  formed,  as  shown  by  figure  18. 

Figures  12  and  13  demonstrate  that  the  thecae  were  oriented  inward 
from  the  beginning  of  the  growth  of  the  colony.  On  account  of  this 
arrangement  they  are  very  rarely  noticeable,  and  it  was  possible  for  Dames 
[1873,  p.383]  to  conclude  that  only  the  upper  free  ends  were  theciferous, 
a  view  which  has  been  accepted  in  Zittel’s  handbook.  In  perfect  rhabdo- 
somes  they  are  only  occasionally  noticeable  in  the  laterally  compressed 
marginal  branches. 

The  early  growth  stages,  before  the  appearance  of  the  transverse  dis¬ 
sepiments,  have  a  considerable  resemblance  to  those  of  Dichograptidae,  a 
fact  noticed  by  Matthews  [1891,  p.38].  This  resemblance  is  indeed  so 
striking,  for  instance  between  the  early  growth  stages  of  D.  flabelli- 
forme  and  Clonograptus  proximatus  Matth.,  both  Cambric,  that, 
when  found  in  the  same  bed,  it  is  somewhat  difficult  to  separate  them. 
Matthew  also  states,  that  the  first  branches  are  formed  by  twice  repeated 
bifurcation.  Our  material  would,  as  we  have  just  described,  rather  indicate 
a  successive  formation  of  the  first  branches,  as  there  occur  stages  with  one, 
two,  three  and  finally  with  four  thecae.  The  resemblance  to  the  mode  of 
branching  in  the  Dichograptidae  is  hence  but  superficial,  and  can  not  be 
otherwise,  since  there  exist  fundamental  differences  in  the  composition  of 


604 


NEW  YORK  STATE  MUSEUM 


the  branches  between  the  Dendroidea,  including  Dictyonema,  and  the 
Graptoloidea,  to  which  the  Dichograptidae  belong.  It  also  follows  from  the 
mode  of  formation  of  thecae  in  D  .  cavernosum,  discovered  by  Wiman 
[1896],  that  the  four  branches  of  the  first  order  should  appear  successively 
instead  of  in  pairs;  for,  as  the  first  budding  individual  appears  together 
with  the  sicula,  and  produces  a  theca,  a  gonangium  and  another  budding 
individual  the  last  of  which,  again,  gives  origin  to  three  different  individuals, 
these  thecae  must,  when  seen  exteriorly,  appear  in  single  succession  and  not 
paired  ;  and  so  must  the  branches. 

While  our  material  does  not  exhibit  the  gonangia  and  budding 
individuals,  it  indicates  the  presence  of  smaller  tubiform  thecae  also  in  this 
species,  for  some  thecae  [fig.5,  8,  9]  are  distinctly  bipartite  and  tripartite,  or 
longitudinally  divided,  for  example  the  middle  one  in  figure  8.  Figure  11 
represents  a  partly  pyritized  specimen,  in  which  the  composite  character  of  the 
thecae  becomes  still  more  apparent. 

Wiman  observed,  by  cutting  the  proximal  part  of  D  .  cavernosum, 
figured  above,  into  thin  sections,  that,  as  soon  as  this  part  begins  to  show 
something  more  than  the  disk,  there  appear  two  individuals,  namely  a 
larger  theca  which  opens  on  the  stem  and  a  smaller  budding  individual.  By 
discussing  the  possible  modes  of  origin  of  these  two  individuals,  he  arrives 
at  the  conclusion  that  two  of  them  are  most  probable  —  namely,  that 
either  a  free  swimming,  nonchitin-secreting  individual  became  sedentary  and 
produced  the  two  first  chitin-secreting  individuals,  or  that  the  theca  was  older 
and  produced  the  budding  individual.  Our  series  of  growth  stages  of 
D.  flabelliforme,  presented  on  plate  1,  tends  to  demonstrate  the 
existence  of  a  primary  theca,  as  the  inception  of  the  colony,  without  any 
adhering  tube,  which  could  represent  the  budding  individual  |  fig.  1].  In  regard 
to  this  theca  Wiman  states,  that  it  is  no  common  nourishing  individual,  i.  e. 
no  theca  in  the  sense  used  for  the  Dendroidea ;  but  for  the  latter  an  entirely 
new  kind  of  individual,  which,  if  not  morphologically,  yet  functionally,  as 
mother  of  but  one  individual,  corresponds  to  the  sicula  of  the  Graptoloidea. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


G05 


Remarks.  The  fact  that  the  rhabdosomes  of  this  species  in  the  usually 
compressed  state  [fig.20]  appear  to  be  derived  from  a  flabelliform  colony,  led 
to  the  early  view  that  these  organisms  had  been  flabelliform,  like  gorgonias. 
Brogger  was  able  to  show  for  D.  flabelliform  e  that  its  rhabdosome 
was  actually  funnel-shaped,  by  finding  specimens  where  the  upper  and  lower 
parts  of  the  rhabdosome  are  not  lying  in  the  same  bedding  plane  and  are 
separated  by  a  thin  layer  of  shale  \l.oc.  tit.  tab.12,  fig.  18].  Such  specimens 
have  been  also  found  among  the  Schaghticoke  material,  where  the  upper 
half  is  partly  broken  away  and  the  lower  half  is  exposed  in  its  place. 
The  early  growth  stages,  and  specially  such  obliquely  compressed  specimens 
as  those  figured  on  plate  1,  figures  16-19,  leave  no  doubt  that  a  cup-shaped 
arrangement  of  the  branches  took  place  from  the  beginning. 

Brogger  describes  a  variety  of  D  .  flabelliforme  as  var.  con- 
f  e  r  t  u  m  Linnarsson  ms.  and  a  mutation,  I)  .  flabelliforme  mut. 
norvegicum  (D.  norvegicum  Kjerulf).  The  variety  confer  turn 
is  said  to  have  a  much  finer  and  closer  network,  and  its  transverse  dis¬ 
sepiments  remain  always  very  thin.  The  mutation  norvegic u m  is 
characterized  by  short  angular  meshes  and  thick  dissepiments.  It  occurs  at 
Vakkero  near  Christiania  in  a  higher  bed  than  the  typical  form.  Matthew 
records  [1892,  p.36]  that  the  variety  confertum  appears  to  be  particularly 
common  in  the  lower  beds  at  St  John  containing  Dictyonema,  and  adds  that 
it  is  distinguished  from  the  typical  form,  found  at  a  higher  level,  by  its 
vasiform  shape.  The  same  author  also  refers  a  form  which  he  found 
in  the  middle  and  upper  Dictyonema  bed  with  some  doubt  to 
D.  norvegicum;  and  describes  the  principal  form  of  St  John  as 
var.  a  cadi  cum,  stating  that  it  differs  from  the  typical  Swedish  D.  fla¬ 
belliforme  by  having  more  numerous  thecae  on  its  branches,  namely  16 
to  17  in  10  mm  against  10  to  15  of  the  typical  form. 

As  Brogger  suggests  it  is  questionable,  on  account  of  the  great  multi 
plicity  of  variations  and  transitions,  -whether  these  varieties  can  be  kept  apart. 
This  has  also  been  the  experience  of  the  writer  with  the  New  York  material. 
In  this,  fragments  bearing  the  characters  of  confert  u m  and  nor- 


NEW  YORK  STATE  MUSEUM 


600 

vegicum  [pl.l,  fig.21,  22]  are  found,  which  however  may  be  only  some¬ 
what  abnormal  portions  of,  in  the  whole,  typical  specimens.  The  majority  of 
the  specimens  are  of  the  typical  form.  As  the  thecae  usually  number  15  and 
frequently  rise  to  16  within  10  mm,  they  would  be  probably  referred  by 
Matthew  to  his  variety,  acadicu  m. 

Dictyonema  murrayi  Hall 

Plate  3,  figure  12 

Dictyonema  murrayi  Hall.  Canadian  Organic  Remains,  decade  2.  1863.  p.138, 
pl.20,  fig.6,  7 

Description.  Rhabdosome  very  large,  its  form  unknown.  Branches 
very  stout,  1.5  mm  wide,  separated  by  slightly  wider  interspaces.  Transverse 
connecting  filaments  straight  and  rigid,  about  3  mm  apart.  Thecae  numbering 
9  to  10  in  the  space  of  10  mm ;  apparently  with  acute  extensions  of  the 
apertural  margins. 

Position  and  localities.  In  greenish,  drab  weathering  sandy  shales, 
between  Defreestville  and  West  Sandlake,  Rensselaer  co.  N.  Y. 
[Hale  coll.] ;  associated  with  Clonograptus  cf.  flexilis  and  Tet- 
ragr  aptus  quadribrachiatus  and  T.  serra.  These  shales 
probably  belong  to  the  Clonograptus  beds  [p.496].  Hall’s  originals 
came  from  hard  shales  of  the  Quebec  group  at  Point  Levis,  where 
the  species  is  associated  with  other  similarly  robust  forms  of 
Dictyonema. 

Remarks.  The  material  of  this  species  obtained  at  the  localit}^ 
mentioned,  is  but  very  fragmentary  and  not  able  to  add  any  new  data  to  the 
already  meager  description  which  Hall  could  furnish. 

Dictyonema  furciferum  sp.  nov. 

Plate  3,  figure  11 

Dictyonema  sp.  nov.  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.570 

Description.  Portion  of  rhabdosome  seen,  flabellate;  21  mm  in  length  by 
9  mm  in  width ;  consisting  of  rigidly  straight  and  parallel  branches  which 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


GOT 

are  not  very  frequently  bifurcating,  the  resulting  branches  forming  an 
acute  angle ;  branches  closely  arranged,  about  14  of  them  being  counted  in 
10  mm;  separated  by  interspaces  of  equal  width 
with  the  branches.  Thecae  acutely  dentiform, 
disposed  on  one  side  of  the  branches ;  number¬ 
ing  16  in  10  mm;  provided  with  a  short,  stout, 
furcate  apertural  process,  which  embraces  the 
dorsal  part  of  the  next  adjoining  branch. 

Position  and  localities.  Rare  at  the  Deep 
kill  in  graptolite  bed  2  (Tetragraptus  zone)  and 
graptolite  bed  3  (zone  with  Didymograptus 
b  if  idu  s  ). 

Remarks.  Besides  small  fragments  and 
less  favorably  preserved  branches  there  has 
been  observed  the  single  larger  specimen  which 
has  been  figured.  This  is  specially  noteworthy 
on  account  of  the  pyritization  of  the  thecae  in 
some  parts  [see  enlarged  text  figure],  whereby 
the  normal  juxtaposition  in  the  branch  of  sev¬ 
eral  (apparently  three)  slender  tubes  becomes 
apparent. 


sp.  nov.  The  composite  character  of  the 
thecae  is  shown  by  a  partial  infiltration  of 

are  prolongations  of  the  thecae  ending  in  component  tubes  with  pyrite.  Deep 
furcate  processes  connects  this  species  with 

D.  cavernosum  and  peltatum  Wiman,  from  the  Lower  Siluric  of  Got¬ 
land,  and  with  D.  cervicorne  Holm,  from  the  Upper  Siluric  of  Gotland. 

Dictyonema  rectilineatum  sp.  nov. 

Plate  3,  figure  10 

cf.  Dictyonema  delicatulum  Dawson.  Can.  Nat.  and  Geol.  1883.  10:461f 

Dictyonema  sp.  nov.  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.570 

Description.  Form  of  entire  rhabdosome  not  known.  Branches  at 
proximal  end  forming  an  irregular  mesh  work ;  iu  a  more  distal  zone  radiat- 


The  character  of  the  dissepiments,  which 


NEW  YORK  STATE  MUSEUM 


(JOS 


ing  and  bifurcating  rapidly ;  in  the  greater  part  of  the  rhabdosome  rigid, 
nearly  straight,  very  closely  arranged  (about  12  to  14  in  10  mm)  and 
extraordinarily  regularly  parallel.  Width  of  branches  .4  mm.  Interspaces 
from  one  to  one  and  a  half  times  as  wide  as  the  branches.  Dissepiments 
very  slender,  not  exceeding  .16  mm  in  width ;  mostly  straight,  a  little 
more  distant  than  the  branches  (about  1  mm)  ;  the  resulting  meshes  hence 

shortly  rectangular.  Branches  dividing  at  an  acute 
angle.  Thecae  not  observed.  Apertures  apparently 
irregularly  disposed,  larger  ones,  approximately  corres¬ 
ponding  in  number  and  position  to  the  dissepiments, 
separated  by  more  numerous  smaller  apertures. 

Position  and  localities.  Rare  in  the  horizon  with 
Diplograptus  dentatus  and  Climaco- 
g  r  ap  t  u  s  ?  antennarius  at  the  Deep  kill. 

Remarks.  This  form  is  evidently  closely  related  if 
not  identical  with  the  species  described  by  Dawson  as 
D .  delicatulum,  which  name,  being  preoccupied 
by  a  species  name  given  by  Lapworth,  was  changed  by 
Gurley  into  D.  per  exile.  However,  as  Dawson  did  not  furnish  any 
drawings,  his  short  description  does  not  allow  any  positive  identification, 
and,  moreover,  as  his  form  has  still  more  closely  arranged  branches  (18  in 
10  mm)  and  occurs  in  another  association  of  species  (Phyllograptus 
typus,  Tetragraptus  bryonoides  and  T .  bigsbyi),  it  was 
not  thought  safe  to  identify  the  form  described  here  with  his  species.  Ami 
has  listed  [1888,  p.ll7k]  a  form  doubtfully  referred  to  Dawson’s  species, 
which  he  cites,  in  recognition  of  the  fact  that  its  name  was  preoccupied, 
as  D  i  c  t  y  o  g  r  a  p  t  u  s  n.  sp.  and  records  as  occurring  at  the  road  from 
Levis  to  St  Joseph  with  Didymograptus  b  i  f  i  d  u  s ,  D  .  extensus, 
D .  furcillatus,  D .  pennatulus,  Tetragraptus  approxi- 
matus,  T.fruticosus,  T .  q  u  a  d  r  i  b  r  a  c  h  i  a  t  u  s  and  T .  serra,  and 
Phyllograptus  typus,  an  association  which  distinctly  points  to  the 
next  older  horizon  than  that  in  which  our  form  is  found  at  the  Deep  kill ; 


Fig.  29  Dictyonema 
rectilineatum  sp.  nov. 
Enlargement  of  part  of  the 
specimen  reproduced  on 
plate  3,  figure  10.  Deep  kill. 
x9 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


GOD 


and  as  also  occurring  at  the  Cliff  facing  the  foundry  at  Levis,  associated  there 
with  the  common  species  of  Tetragraptus  and  Diplograptus 
dentatus,  an  association  which  would  indicate  a  transitional  bed 
between  the  horizons  of  D  i  d  y  m  ograptus 
bifid  us  and  Diplograptus  dentatus. 

DESMOGRAPTUS  HopkillSOU 

The  name  Desmograptus  was  proposed  by 
Hopkinson  [1875,  p.668 1  as  a  subgeneric  term  of 
Dictyonema  for  forms  in  Avhich,  as  in  the  genotype, 

D.  c  ancellatus,  “ the  meshes  or  interspaces  are 
chiefly  formed  by  the  branches  coalescing  and  divid¬ 
ing  by  virtue  of  their  curvilinear  direction.”  The 
flexuous  and  anastomosing  course  of  the  branches 
forms  a  character  so  readilv  recognized  and  so  dis- 
tinctive  of  a  group  of  species,  that  we  have  no  hesi¬ 
tation  in  recognizing  the  latter  as  a  genus.  This  is 
represented  in  the  Deep  kill  fauna  by  two  species. 

The  presence  of  occasional  dissepiments  and  of 
parts  with  more  straightened  branches  in  D .  i  n  t  r  i  - 
cat  us  suggests,  however,  that  the  structural  differ-  Pig.  30  Desmograptus  intri- 

.  T,.  .  —v  .  cat  us  sp.  nov.  Enlargement  of 

ences  between  Dictyonema  and  Desmograptus  may  proximal  portion  showing  transi- 

J  ~  1  tion  from  straight  to  undulating 

not  be  as  great  as  it  would  appear  from  their  widely  x5a25Ches  m  lowei  part'  Deep  klU' 
different  aspects.  Of  special  interest  in  regard  to 

this  relationship  is  the  basal  part  of  the  specimen,  reproduced  in  figure  30, 
which  shows  in  the  oldest  proximal  part  parallel  branches  and  true,  stout 
dissepiments.  This  Dictyonema  structure  rather  abruptly  changes  into  the 
Desmograptus  structure  with  irregular  and  coalescing  branches,  a  change 
which  indicates  the  development  of  Desmograptus  from  the  typical,  also 
geologically  older  Dictyonema. 


NEW  YORK  STATE  MUSEUM 


010 


Desmograptus  cancellatus  Hopk.  (sp.) 

Plate  3,  figures  5-8 

Dictyograptus  (Desmograptus)  cancellatus  Hopkinson.  Quar.  Jour. 

Geol.  Soc.  1875.  31:668,  pl.36,  tig.  11a,  lib 
cf.  Desmograptus  macrodictyum  Gurley.  Jour.  Geol.  1896.  4:83f 

Dictyonema  (Desmograptus)  cancellatum  Ruedemann.  N.  Y.  State 
Paleontol.  An.  Rep’t.  1902.  p.570 

Description.  Rhabdosome  infnndibuliform,  beginning  with  a  chitinous, 
apparently  nonsiculate  basal  expansion,  and  a  short  stem.  Branches  thick, 
undulating,  in  the  proximal  part  little  flexuous  and  subparallel,  distally 

becoming  gradually  more  undulating;  forming  by  coales¬ 
cence  and  redivision  in  the  proximal  parts  long  narrow 
meshes ;  in  the  distal  parts  elongate  to  broadly  oval  meshes. 
These  are  in  the  mature  parts  about  twice  as  wide  as  the 
branches  and  three  to  four  times  as  long  as  wide.  Branches 
12  to  14  in  10  mm.  Thecal  apertures  circular,  not  promi¬ 
nent,  appressed  to  branches,  apparently  closely  arranged. 
Dissepiments  rarely  observable.  Bifurcation  of  branches 
quite  regular,  leading  to  a  regular  gradual  expansion  of  the 
rhabdosome. 

Position  and  localities.  Common  in  graptolite  bed  7 
of  the  Deep  kill  section  (horizon  with  Diplograptus 
dentatus  and  Climacograptus?  antennarins)_ 
D.  cancellatus  was  described  as  coming  from  the  Lower  Arenig 
of  White  sand  bay  of  St  David’s,  which  is  stated  to  be  overlain  by  Middle 
Arenig  beds  containing  some  of  Hall’s  species  of  Tetragraptus,  Callograptus 
and  Didymograptus,  occurring  here  in  the  Tetragraptus  beds.  It  would, 
therefore,  seem  that  the  British  species  is  considerably  older  than  the  Deep 
kill  form,  referred  to  it.  As,  however,  Trigonograptus  ensiformis, 
a  typical  species  of  the  third  Deep  kill  horizon,  in  which  D.  cancel¬ 
latus  occurs,  is  cited  as  having  been  found  in  the  Lower  Arenig  of  White- 
sand  bay,  it  is  possible  that  at  the  latter  locality  the  beds  are  inverted  or 


Fig.31  Desmograp¬ 
tus  cancellatus 
Hopkinson  (sp.)  Enlarge¬ 
ment  of  part  of  specimen 
reproduced  on  plate  3, 
figure  7.  Deep  kill.  x3.75 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


611 


otherwise  disturbed,  and  the  terms  Lower  and  Middle  Arenig  should  be 
exchanged. 

If,  however,  the  species  recorded  by  Gurley  from  the  Main  Point  Levis 
zone  which  corresponds  to  the  Tetragraptus  beds  of  the  Deep  kill  section  is 
identical  with  our  form,  the  latter  would  range  from  the  Tetragraptus  horizon 
to  that  with  Diplograptus  dentatus. 

Remarks.  This  form,  in  some  of  its  distal  parts,  agrees 
so  closely  with  the  description  and  figure  of  Dictyograp- 
tus  (Desmograptus)  cancellatus,  that  a  separa¬ 
tion  from  this  species  does  not  appear  to  be  justified.  The 
only  apparent  difference  is  the  greater  width  of  the  branches 
in  the  Welsh  specimen,  a  feature  which  in  view  of  the  varia¬ 
bility  of  the  thickness  of  the  branches  in  the  Deep  kill  speci¬ 
mens  can  not  be  considered  as  of  diagnostic  value.  The  figure 
of  the  type  specimen  which  is  a  representation  of  a  more 
distal  part  shows  also  the  presence  of  more  elongate  meshes 
in  a  basal  direction. 

Gurley  described  a  form  from  the  Beekmantown  shales  of  Point  Levis 
as  D  .  macrodictyum,  which  is  said  to  differ  from  D.  cancellatus 
by  the  straight  branches,  the  greatly  elongate  meshes  and  the  generally 
stouter  structure.  As  the  specimens  figured  here  exhibit  these  same 
differences  between  basal  and  distal  parts  of  the  rhabdosome,  it  is  probable 
that  his  type  is  also  referable  to  this  species  and  belongs  only  to  a  more 
basal  portion  than  the  original.  Since  Dr  Gurley  did  not  figure  his  species, 
which  was  found  in  the  Main  Point  Levis  zone,  a  definite  reference  is 
excluded  at  present. 

Desmograptus  intricatus  sp.  nov. 

Plate  3,  figures  1-4 

Dictyonema  (Desmograptus)  sp.  nov.  Ruedemann.  N.  Y.  State  Paleontol. 

An.  Rep’t.  1902.  p.570 

Description.  Phabdosome  infundibuliform ;  rapidly  widening  by  oft 
repeated  bifurcations  of  the  branches,  attaining  a  length  and  width  of 


Fig.  32  Desmo¬ 
graptus  Intri¬ 
catus  sp.  nov.  En¬ 
largement  of  part  of 
the  specimen  repro¬ 
duced  on  pl.3,  fig.3. 
Deep  kill.  x6 


612 


NEW  YORK  STATE  MUSEUM 


50  mm.  Branches  thin  (.1mm),  very  closely  arranged,  numbering  16  to  20 

in  10  mm,  subparallel,  undulating  and  coalescing  at  the 
contact  points,  forming  elongate  meshes,  eight  of  which 
have  a  length  of  10  mm.  True  dissepiments  occurring  but 
rarely.  Thecal  apertures  not  prominent,  appressed,  appear¬ 
ing  as  closely  arranged  circular  pores. 

Position  and  localities.  Very  common  in  graptolite 
bed  7  of  the  Deep  kill  section,  belonging  to  the  horizon 
with  Diplograptus  dentatus. 

Remarks.  This  species  is  readily  distinguished  by  the 
delicacy  of  its  structure  and  the  small  size  of  its  meshes 
from  D.  cancellatus,  which  occurs  in  the  same  bed, 
and  by  the  undulating  character  of  its  branches  from 
Dictyonema  rectilineatum,  a  similarly  fine 
meshed  form  of  the  same  horizon. 

Order  2  graptoloidea  Lapworth 
Suborder  A  graptoloidea  axonolipa  Freeh,  em.  Rued- 
Family  dichograptidae  auct.  em.  Freeh 
staurograptus  Emmons 

(=  Clematograptus  Hopkinson  and  Clonograptus  Hall  in  part) 

Emmons  proposed,  in  the  second  part  of  his  American  Geology 
[1855,  p.108]  the  new  genus  Staurograptus  for  a  minute  form,  which  he 
had  found  in  the  “  Taconic  shales  of  Rensselaer  county,  N.  Y.”  His  defini¬ 
tion  of  the  genus  is :  “  Disk  free,  cruciform,  arms  four,  dichotomous  cells 
terminal,  substance  membranaceous,  free  and  furnished  with  an  axis.”  This 
genus  has,  on  account  of  the  peculiar  aspect,  the  cruciform  division  in  the 
center  and  the  peculiarly  broad  dichotomous  appendages  [see  Emmons’s  two 
drawings,  reproduced  here]  of  the  genotype,  S.  dicliotomus,  been  con¬ 
sidered  as  doubtful  at  the  beginning  and  later  suffered  still  worse  fate,  for  it 
has  in  all  newer  works  on  graptolites  been  delivered  to  complete  oblivion. 


Pig.  33  Desmograp- 
t u s  intricatus.  En¬ 
largement  of  portion  of 
the  specimen  reproduced 
on  pl.3,  fig.l.  x8 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


613 


Fig.  34  Staurograptus  dicli oto- 
m  u  s  Emmons.  Copy  of  original  figures 


The  only  note  on  the  genus,  which  is  known  to  me,  is  that  by  Hall 
[1865,  p.43]  which  reads:  “The  typical  and  only  species  of  Staurograptus 
of  the  same  author  is  a  very  remarkable  form  of  extremely  minute  pro¬ 
portions.  Its  mode  of  growth  and  subdivision  of  stipes,  if  accurately  repre¬ 
sented  in  the  figure,  are  unlike  anything  known  -among  this  family  of 
fossils,  and  it  merits  generic  distinction.”  Lapworth  refers  to  it  [1887,  p,168j 
as  the  “dubious  genus  Staurograptus  of  Emmons.” 

I  have  now  found  in  the  same  region  whence  Emmons  obtained  this 
material,  in  slates  associated  with  the  Upper 
Cambric  Dictyonema  flabelliforme  bed,  a  com¬ 
plete  series  of  growth  stages  [pi. 2]  leading 
from  the  sicula  through  stages  identical  with 
Emmons’s  Staurograptus  dichotomus 
to  Clonograptus  proximatus,  a 
species  described  by  Matthew  from  the  Upper 
Cambric  of  the  St  John  basin.  Though  the 
mature  specimens  of  the  species  look  very  different  from  the  growth  stage 
which  Emmons  happened  to  have,  the  right  of  priority  requires,  I  think, 
the  recognition  of  his  generic  and  specific  terms. 

It  is  evident  from  Emmons’s  description  that  he  considered  his  specimen 
as  full  grown,  and  as  having  normally  “  dichotomous  cells  terminal,”  but  this 
does  not  vitiate  the  fact  of  his  recognizing  the  differential  character  of  this 
form,  consisting  in  the  cruciform  center. 

The  recognition  of  the  generic  term  Staurograptus  would  make  Hall’s 
term  Clonograptus  a  void  synonym,  in  case  the  mature  form  here  described 
should  be  referable  to  the  latter  genus.  It  is  however  certain  that  the 
form  presents,  in  its  mature  stage,  characters  of  Hopkinson’s  genus  Clemato- 
graptus  [1875,  p.652].  The  latter  is  characterized  in  its  type  species, 
Cl.  implicatus  Hopk.,  by  the  radial  disposition  of  its  branches,  which 
branch  so  closely  to  the  sicula  that  they  all  appear  to  spring  at  once  from 
the  center,  and  that  the  “  funicle  ”  of  other  Dichograptidae  is  hardly  notice¬ 
able.  This  concentration  of  branching  of  the  rhabdosome  in  the  early 


614 


NEW  YORK  STATE  MUSEUM 


stages,  causing  a  bushlike  mode  of  branching  [pl.2,  fig.13,  14,  16]  is  the  only 
difference  which  the  writer  can  find  between  Clonograptus  and  Clemato- 
graptus,  and  it  is  quite  probable  that  this  is  of  no  more  than  subgeneric 
importance.  As,  however,  the  latter  genus  has  been  commonly  recognized 
and  comprises  a  small  group  of  forms  which  is  well  characterized  by  the 
feature  mentioned,  we  will  distinguish  it  here  also  though  under  the  older 
term  Staurograptus. 

Staurograptus  dichotomus  Emmons 

Plate  2,  figure  1-24 

Staurograptus  dichotomus  Emmons.  Am.  Geol.  pt2.  1855.  p.109,  pl.l, 
fig  21 

cf.  Bryograptus  patens  Matthew.  Roy.  Soc.  Can.  Trans,  and  Proc.  1893. 
v.10,  §4,  p.17,  pl.7,  fig.la,  lc,  Id 

Clonograptus  proximatus  Matthew.  N.  T.  Acad.  Sci.  Trans.  1895.  14:265, 
pl.48,  fig.la-d 

cf.  Bryograptus  patens  Matthew.  N.  Y.  Acad.  Sci.  Trans.  1895.  14:268, 
pl.48,  fig.4a,  4b1 

cf.  Bryograptus  lent  us  Matthew.  N.  Y.  Acad.  Sci.  Trans.  1895.  14:270, 
pl.48,  fig.2a,  2b 

Clonograptus  proximatus  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t. 
1903.  p.938 

Bryograptus  patens  Ruedemann.  Ibid.  1903.  p.938 
Bryograptus  lentus  Ruedemann.  Ibid.  1903.  p.938 

Description.  Rhabdosome  broadly  conical  to  saucer  shaped;  mostly 
found  vertically  compressed  or  spread  out.  Sicula  short  (about  1.8  mm  long) 
and  slender  conical,  suspended  by  means  of  a  delicate  nema,  which  attains 
four  times  the  length  of  the  sicula  and  has  not  been  observed  in  grown 
specimens,  from  a  chitinous  disk  that  in  diameter  approximately  equals 
the  length  of  the  sicula  [pl.2,  fig.l].  Primary  thecae  (“funicle”)  growing 
in  direction  of  the  sicula,  rhabdosome  hence  apparently  beginning  with  four 
or  more  branches.  Rhabdosome  attaining  a  diameter  of  40  mm,  consisting 
of  numerous  (upward  of  40)  branches  of  the  last  order.  Branches  slender 


1  Figure  4c  appears  to  me  to  represent  an  early  growth  stage  of  Dictyonema  flabelliforme 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


615 


(about  .4  mm  wide  in  the  dorsal  aspect  and  .6  mm  in  the  lateral  aspect), 
straight  in  the  central  parts  and  slightly  flexuous  in  the  distal  region, 
branching  dichotoinously  in  irregular  intervals.  Branches  of  six  orders 
observed ;  the  bifurcation  of  the  first  branches  takes  place  under  right 
angles,  those  of  succeeding  orders  under  angles  of  50°-70°,  the  angles  of 
bifurcation  decreasing  distally.  The  thecae  number  11-13  in  10  mm;  they 
are  inclined  at  a  constant  angle  of  25°,  and  are  in  contact  for  a  little 
more  than  one  third  of  their  length ;  their  outer  walls  are  straight  or 
slightly  concave,  the  apertural  margin  gently  convex  and  nearly  vertical 
on  the  axis. 

Position  and  localities.  Common  in  the  Upper  Cambric  slates  at 
Schaghticoke  N.  Y.  It  occurs  undoubtedly  at  other  places  in  the  slate 
belt,  in  Rensselaer  and  Washington  counties,  in  association  with 
Dictyonema  flabelliforme.  It  is,  for  instance,  very  common  in 
Upper  Cambric  slates  from  Hillsdale  near  Granville,  Washington  co. 
Emmons  obtained  his  types  from  the  Taconic  slates  of  Rensselaer  county, 
N.  Y.  Matthew  records  the  species  as  occurring  in  bands  of 
division  3  of  the  St  John  group,  where  it  is  also  associated  with 
D.  flabelliforme. 

Development.  This  species  has  furnished  a  complete  series  of  growth 
stages.  These  begin  with  (1)  the  sicula  [pl.2,  fig.l,  2],  which  is  suspended 
by  a  rather  short  nema  from  a  thin  chitinous  disk ;  (2)  the  sicula  produces 
at  about  one  third  of  its  final  length  the  first  theca  [fig.3],  which  grows 
appressed  to  the  sicula  nearly  as  far  as  the  latter’s  aperture  and  thence  turns 
to  the  left  [fig. 4,  5,  6J ;  (3)  from  the  first  theca  originates  at  about  one 
fourth  of  its  length  [fig.4]  the  second  theca,  which  also  grows  along  the 
sicula  to  the  point  of  departure  of  the  first  theca  and  then  turns  to  the  right 
side.  The  “  funicle  ”  of  other  dichograptids,  which  is  composed  of  these 
two  thecae,  is,  hence,  here  not  noticeable  in  a  horizontally  spread  out 
colony.  (4)  Both  primary  thecae  produce  by  budding  in  rapid  succession 
two  apparently  dichotomous  branchings  [fig.6]  close  to  the  aperture  of  the 
sicula ;  thus  giving  origin  to  the  cruciform  division  in  the  center  of  the 


610 


NEW  YORK  STATE  MUSEUM 


colony,  when  seen  in  a  vertically  compressed  condition  [fig. 8- 10].  The 
cross  of  branches  stood  vertically  on  the  axis  of  the  sicula  or  had  a 
horizontal  position  in  the  suspended  rhabdosome  as  is  illustrated  by  figures  7 
and  17.  (5)  The  four  branches  of  the  second  order  form  at  once  new 

bifurcations.  One  of  them  lies  usually  a  little  closer  to  the  center  [fig.9-11] 
than  the  others,  thus  often  giving  to  the  colony  the  appearance  of  having  pos¬ 
sessed  a  six  rayed  center  [fig.l2-14J.  The  stage  with  the  four  branches 
of  the  second  order  and  the  eight  branches  of  the  third  is  that 
which  Emmons  figured  and  employed  to  base  his  S.  dicliotomus  on. 
(6)  The  later  branches  bifurcate  irregularly  and  apparently,  as  in  Clono- 
graptus,  without  limitation.  (7)  The  laterally  compressed  specimens 
[fig.  17-21]  show  that  the  branches  at  the  beginning  grew  in  a  nearly 
horizontal  direction  [fig.17,19],  but  later  on  turned  obliquely  downward,  the 
whole  rhabdosome  thus  forming  an  inverted  broad,  low  cone  [fig.20,21]  with 
an  apical  angle  of  110°-120°. 

j Remarks.  Where  the  initial  branching  is  not  very  distinct,  a  criterion 
by  which  the  last  mentioned  laterally  compressed  forms  could  be  distin¬ 
guished  from  species  of  Bryograptus  is  lacking;  and  without  the  presence  of 
the  other  flat  mode  of  preservation  and  the  growth  stages  they  could  hardly 
help  being  considered  as  belonging  to  that  genus.  It  is  evidently  for  these 
reasons  that  Matthew  [1895]  has  described  two  species  of  Bryograptus  as 
associates  of  the  species  under  discussion,  which,  from  the  extensive  material 
collected  at  Schaghticoke,  1  believe  to  be  other  modes  of  preservation  of 
S .  di  chotomus.  In  a  preliminary  paper  on  the  Dictyonema 
flabelliforme  beds  in  New  York  [1903,  p.938  ]  the  writer  has  also  listed 
these  species  of  Bryograptus  which  he  at  first  thought  to  be  well  distin¬ 
guished  from  Staurograptus. 

While,  however,  the  Bryograptuslike  mode  of  preservation  is  by  far 
the  rarer  —  as  is  also  stated  by  Matthew  —  both  the  normal  Staurograptus 
and  the  Bryograptus  form  have  been  noticed  in  the  same  specimen,  one 
part  of  which  had  been  flattened  vertically  and  another  compressed  laterally. 
This  supports  the  suggestion  of  Elies  1 1898,  p.532]  that  “  great  variation 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


617 


might  be  observed  in  a  delicafe  Clonograptus  form  in  the  angles  at  which 
the  stipes  of  various  orders  were  inclined  to  each  other.”  For,  if  we  con¬ 
sider  the  rhabdosome  to  have  been  free  floating  or  attached  to  some 
floating  body,  and  its  branches  as  flexuous,  it  is  obvious  that  the  latter 
might  ultimately  come  to  rest  in  quite  different  positions. 

Staurograptus  dichotomus  var.  apertus  var.  nov. 

Plate  2,  figures  22-24 

There  have  been  found  in  the  Upper  Cambric  beds  of  Schaghticoke  and 
of  Hillsdale  near  Granville,  specimens  of  S  .  die  h  o  t  o  m  u  s  which  contrast 
with  the  great  majority  of  the  individuals  by  their  greatly  reduced  bifurca¬ 
tion  and  a  correspondingly  much  smaller  number  of  branches.  The  latter 
appear,  in  the  extreme  cases,  as  the  original  of  figure  22,  to  have  but 
branches  of  the  first  two  orders.  There  are  no  differences  observable  in 
the  character  of  the  thecae  and  transitional  forms,  as  the  one  reproduced  in 
figure  23  demonstrates  the  close  connection  of  these  forms  with  the  types  of 
the  species. 

This  variety  bears  some  similarity  to  Graptolitlius  milesi  Hall 
[Geol.  Vt.  1861,  1:372,  figured  v.  2;  1861,  pl.12,  fig.2-4]  in  the  mode  of  its 
branching  and  the  character  and  number  of  its  thecae.  It  has  in  the 
preliminary  paper  cited  above  [1903,  p.938]  been  referred  provisionally  to 
that  species.  A  direct  identification  is  prohibited  by  the  statement  of  the 
presence  of  a  horizontal  “funicle  ”  in  G .  milesi,  which  species  then  is  to 
be  referred  to  Clonograptus1. 


1This  species  lias  been  referred  by  Nicholson  [1876,  p.24S]  to  his  new  genus 
Teranograptus.  Herrmann  did  not  recognize  that  genus  [1886,  p.25]  and  referred  its 
species  to  Clonograptus ;  while  Freeh  [1897,  p.596]  follows  Nicholson,  and  refers  both 
species,  Temnograptus  milesi  and  T.  multiplex,  to  Temnograptus,  sug¬ 
gesting  that  they  may  be  identical.  A  comparison  of  the  drawings  of  Clono¬ 
graptus  milesi  with  those  furnished  of  Temnograptus  multiplex  by 
Nicholson  [op.  cit.~\  and  Elies  [op.  cit.  p.479,  fig.6]  leaves  however  no  doubt  that  in  the 
former  species  the  branching  is  typically  dichotomous,  while  in  Temnograptus  it  is 
monopodial  or  lateral,  notwithstanding  the  fact  that  Nicholson  and  Elies  cite  the  wholly 


018 


NEW  YORK  STATE  MUSEUM 


CLONOGRAPTUS  Hall.  1873 
Clonograptus  cf.  flexilis  Hall 

Graptolithus  flexilis  Hall.  Geol.  Sur.  Can.  Rep’t  for  1857.  1858.  p.119 
Graptolithus  flexilis  Hall.  Canadian  Organic  Remains,  decade  2.  1863. 

p.103,  pi. 10,  fig.3-9 

Only  fragments  of  a  form,  not  sufficient  for  definite  determination, 
but  probably  belonging  to  this  species,  have  been  collected  by 
T.  N.  Dale  at  a  locality  between  Defreestville  and  West  Sandlake, 
Rensselaer  co.  N.  Y. 

TEMNOGRAPTUS  Nicholson 

Fragments  of  a  very  coarse  and  massive  graptolite  [pl.5,  fig.15-20] 
demonstrate  the  presence  in  the  Deep  kill  beds  of  a  single  representative 
of  a  peculiar  group  of  multiramous  types  of  truly  gigantic  dimensions 
when  measured  by  the  average  graptolites.  Some  rhabdosomes  of  this 
group  of  forms  covered  an  area  of  1  qm  and  more.  The  whole  aggregation 
which  is  typically  represented  by  the  genus  Temnograptus,  and  to  which, 
besides,  belong  the  genera  Schizograptus,  Trochograptus,  Holograptus  and 
Rouvilligraptus,  is  characterized  by  the  large  size  of  the  multiramous  rhabdo¬ 
somes,  the  mostly  considerable  thickness  of  the  branches,  the  widely 
and  equally  separated  points  of  branching  and  the  strong  development  of 
the  lateral  branching.  All  these  features  give  to  the  group  a  uniform  habit 
quite  distinct  from  that  of  the  other  graptolites. 

dichotomous  branching  as  one  of  the  distinctive  characters  of  Temnograptus.  That  in 
T.  multiplex  the  branching  is  indeed  monopodial  becomes  evident  in  Nicholson’s 
and  Elles’s  drawings,  which  show  that  one  of  the  branches  resulting  from  the 
division  follows  the  curvature  of  the  mother  branch,  while  the  other  alone  assumes 
a  new  direction.  Only  the  branches  of  the  first  order  divide  dichotomously ;  and  it  is 
hence  probable  that  no  difference  can  be  found  between  this  and  Holm’s  genus  Trocho¬ 
graptus,  as  according  to  Elles’s  table  [p.478]  the  mode  of  branching  constitutes  the  only 
difference  between  the  two. 

W e  believe,  for  these  reasons,  that  Clonograptus  milesi  and  Temno¬ 
graptus  multiplex  belong  to  quite  different  series  of  the  dichograptids. 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


619 


Of  the  above  named  genera,  Temnograptus  shows  still  in  its  branching 
the  nearest  approach  to  the  original  dichotomy,  the  others  possessing  mostly 
a  more  distinctly  lateral  mode  of  branching,  and  it  also  has  still  the  greatest 
number  of  orders  of  branches;  hence  it  seems  to  be  nearest  to  the 
ancestral  Clonograptus  forms,  and  therefore  may  have  been  the  radicle  of  the 
others. 

In  the  American  graptolite  beds  this  group,  which  in  Europe  is  well 
developed,  is  but  poorly  represented.  A  single  other  species  besides  the  form 
here  described  has  become  known,  viz  Hologr  aptus  richardsoni, 
from  the  Quebec  beds. 

Temnograptus  noveboracensis  sp.  nov. 

Plate  5,  figures  15-20 

Temnograptus  cf.  m  u  1 1  i  p  1  e  x  (Nicholson)  Ruedemann.  N.  T.  State  Paleontol. 

An.  Rep’t.  1902.  p.556. 

In  graptolite  bed  2,  representing  the  upper  part  of  the  Tetragraptus 
shale,  frequently  occur  fragments  of  a  large  branching 
dichograptid  of  strikingly  different  habit  from  the  asso¬ 
ciated  forms.  As  no  entire  specimen  has  been  observed, 
the  structure  of  the  rhabdosome  could  be  obtained  only 
by  a  combination  of  fragments.  This  proves  the  form 
in  question  to  have  possessed  a  short  stout  “  funicle,” 
from  which  branched  by  dichotomy  four  long  denticu¬ 
late  secondary  branches,  which  in  long  intervals  bifur¬ 
cated  again.  There  were  branches  of  at  least  four 
orders. 

Description.  Branches  of  first  order  short  (5.5  mm), 

,  „  ,  ,  -|  -i  Fig.  35  Temnograptus 

stout;  those  o±  the  second  and  following  orders  long  noveboracensis  sp.nov. 

°  ~  Fragment  of  rhabdosome 

(50+mrn),  forming  an  angle  of  130°.  Branches  of  the  ?o?m  of  thecae?atDeep  kSf. 
higher  orders  bifurcating  under  smaller  angles,  the  latter 

apparently  diminishing  with  the  increasing  distance  from  the  base  of  the 
rhabdosome.  Angles  of  70°,  30°  and  10°  have  been  measured  in  various 


620 


NEW  YORK  STATE  MUSEUM 


branches.  Bifurcations  very  far  apart,  longest  branch  215  mm,  maximal 
width  of  branch  (much  flattened  out)  2.4  mm.  Thecae  numbering,  appar¬ 
ently,  10  in  10  mm,  little  prominent,  inclined  at  a  low 
angle  (about  10°). 

Position  and  locality.  Graptolite  bed  2  (Tetra- 
graptus  horizon)  of  the  Deep  kill  section. 

Pemarks.  This  species,  which  is  the  only  repre¬ 
sentative  of  the  entire  group  in  the  Deep  kill  beds, 
is  distinguished  from  the  type  species  of  the  genus, 
Temnograptus  multiplex,  by  the  straight 
direction  and  more  rigid  appearance  of  the  branches 
and  the  smaller  angles  of  divergence  of  the  branches 
and  of  inclination  of  the  thecae.  From  Holograp- 
tus  richardsoni  Hall  (sp.),  its  only  closer 
American  relative,  it  differs  by  its  much  more  widely  separated  points  of 
bifurcation,  more  nearly  dichotomous  branching  and  smaller  angle  of  inclina¬ 
tion  of  the  thecae. 


Fig.  36  Temnograptus 
noveboracensis  sp.  nov. 
Fragment  of  a  slightly  ob¬ 
liquely  compressed  branch. 
Dorsal  view  showing  the  in¬ 
ternal  apertures  of  the  the¬ 
cae.  Deep  kill.  x3 


goniograptus  McCoy.  1877 

The  genus  Goniograptus  was  proposed  by  McCoy  [1876,  p.128]  for 
“  such  types  as  the  present,  in  which  the  branches  of  the  funicle  (for  which 
I  would  suggest  the  name  stolons)  are  regularly  bent  at  the  points  of 
budding  into  the  celluliferous  stems.”  The  genus  was  recognized  by  Lap- 
worth,  while  Roemer  and  Freeh,  from  the  point  of  view  that  the  mode  of 
branching  is  of  little  generic  importance  in  comparison  with  that  of  the 
form  of  the  thecae,  are  inclined  to  refer  Goniograptus  to  Clonograptus,  which 
is  retained  as  a  subgenus  of  Dichograptus. 

While  in  Clonograptus  the  branching  takes  place  entirely  irregularly 
and  thus  represents  a  primitive  stage  of  development,  it  has  become  rigidly 
fixed  in  Goniograptus  in  such  a  fashion  that  four  zigzagged  principal  axes 
are  formed,  from  the  angles  of  which  regularly  spring  undivided  branches. 
The  peculiar  direction  of  development  taken  by  this  species  appears 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


621 


not  to  have  •  been  fruitful  of  further  forms,  like  the  main  stem 
of  the  Clonograptus  forms,  and  the  small  branch  became  soon  extinct. 
There  have  been  found  two  more  forms  in  the  Deep  kill  beds  with  the 
same  rigid  Goniograptus  structure,  but  thecae  of  different  dimensions.  These 
forms  show  that  there  exists  a  whole  group  presenting  these  characters  of 
structure  different  from  those  of  Clonograptus  arid  requiring  recognition. 
But  their  different  thecae  leave  also  little  doubt  that  the  genus  is  polyphy- 
letic  [ch.10,  p.561].  The  name  then  still  would  designate  a  definite  phyletic 
stage  or  tendency  of  development  which  it  seems  became  manifest  only  in  the 
Pacific-American  basin  [p.503]. 

Goniograptus  thureaui  McCoy 

Plate  6,  figures  1-15 

Didymograptus  (Goniograptus)  thureaui  McCoy.  Ann.  and  Mag.  Nat. 
Hist.  ser.  4.  1876.  18:128-130 

Graptolites  (Didymograptus)  thureaui  McCoy.  Geol.  Sur.  Victoria. 

Prodr.  Pal.  Victoria,  decade  5.  1877.  p.39,  40 

Goniograptus  thureaui  var.  selwyni  Ami.  Can.  Record  Sci.  1889. 
3:422-28,  p.502,  503,  fig.l,  2 

Goniograptus  thureaui  Ami.  Geol.  Sur.  Can.  Rep’t.  ser.  2.  1889.  v.3,  pt2, 

p.l  16k 

Dichograptus  (Clonograptus,  Goniograptus)  thureaui  Freeh. 

Lethaea  palaeozoica,  Bd  1,  Lief.  3.  1897.  p.600,  fig.165 

Goniograptus  thureaui  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.556,  565,  576-92 

Among  the  many  pretty  patterns  of  graptolite  structure  occurring  in 
the  zones  with  Tetragraptus  and  Didymograptus  bifid  us 
undoubtedly  the  most  beautiful  is  G.  thureaui  McCoy.  Our  interest 
in  this  form  is  enhanced  by  its  peculiar  distribution  and  the  fact  that  it 
has  left  a  complete  record  of  its  ontogeny  [1902,  p.576]. 

The  form  was  first  made  known  by  McCoy  from  the  black  and  red 
auriferous  slates  of  the  Bendigo  gold  field,  at  Sandhurst,  Victoria, 
Australia,  and  the  new  genus  Goniograptus  based  on  the  same.  In 
1889  Dr  Ami  announced  the  discovery  of  this  remarkable  graptolite  in  the 


022 


NEW  YORK  STATE  MUSEUM 


Tetragraptus  shale  of  the  Levis  beds  in  Canada,  noting  in  a  description 
of  the  same  the  presence  of  a  central  disk  which  had  not  been  observed  in 
Australia. 

Description.  The  rhabdosome  consists  of  two  short  monothecal  branches 
of  the  first  order  (“  funicle  ”)  growing  from  a  relatively  long,  stout  sicula 
(2. 2-2. 7  mm  in  different  specimens).  The  “funicle”  varies  from 

2 . 3  to  3mm  in  length.  It  divides 
by  dichotomy  at  both  ends  into 
two  short  branches  of  the  sec- 

Fig.  37  Goniograptus  thureaui  McCoy.  Fragment  of  Olid  Order  which  form  an  angle 
a  branch  in  which  the  coenosarcal  canal  and  the  proximal  por-  ° 

tions  of  the  thecae  have  become  infiltrated  with  pyrite  and  the  •  -i  oao  1  a  no 

successive  gemmation  of  the  thecae  is  well  shown.  Deep  kill.  Varying  OetWeen  loU  anu  14:0  . 
x 5.JJ5  -  , 

These  bifurcate  again,  forming 
two  branches,  one  of  which  grows  out  into  an  undivided  denticulate  branch, 
while  the  other  monothecal  one  bifurcates,  producing  a  denticulate  branch 
on  the  opposite  side.  This  process  is  repeated  till  four  zigzag  shaped, 
principal  stems  are  formed,  reaching  a  length  of  10  mm 
and  lying  approximately  in  the  diagonals  of  a  rectangle, 
forming  two  pairs  of  angles,  the  one  at  the  end  of 
the  “funicle”  being  about  75°,  the  other  on  both  sides 
of  the  same  105°.  The  denticulate  branch  forms  an 
angle  of  45°  with  the  stem  and  the  last  pair  of  suc¬ 
ceeding  denticulate  branches  form  approximately  a 
right  angle  at  their  bases.  The  whole  rhabdosome 
expands  in  the  form  of  a  square  with  convex  sides. 

Well  preserved,  mature  specimens  often  possess  a 
chitinous  disk  which  clasps  the  “  funicle  ”  and  the 

principal  branches  to  the  base  of  the  terminal  denticulate  branches.  The 
breadth  of  this  alate  extension  has  not  been  found  to  surpass  1 . 3  mm. 
The  diameter  of  the  largest  colonies  was  observed  to  be  110  mm.  The 
thecae  are  long  and  narrow,  number  8  to  10  in  10  mm,  overlap  about  one 
half  of  their  length ;  their  outer  walls  are  slightly  concave  and  are 
inclined  at  about  30°  to  the  axis  of  the  branch  in  the  distal  parts;  their 


Fig.  38  Goniograptus 
thureaui  McCoy.  Frag¬ 
ment  of  branch  enlarged. 
Deep  kill.  x4.5 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


623 


apertural  margins  are  also  concave  and  form  an  angle  of  80°  with  the  axis 
of  the  branch. 

Position  and  localities.  G .  thureaniis  common  in  graptolite  bed  2 
(Tetragraptus  zone),  but  extends  apparently  in  diminished  size  and  develop¬ 
ment,  into  the  next  zone,  that  with  Did  ymograptus  bifidus.  In 
Canada  it  is  according  to  Ami’s  lists  restricted  to  one  locality  at  Levis, 
where  it  is  associated  with  the  Tetragraptus  fauna.  McCoy  recorded  the 
originals  as  occurring  in  the  “  Llandeilo  ”  of  the  Bendigo  gold  field  of 

Australia.  It  is  however  certain  that  it  there  also  occurs  at  about  the 

same  horizon  in  rocks  of  Arenig  age.  The  significance  of  the  distribution  of 
this  form  for  the  reconstruction  of  the  paleozoic  marine  basins  has 
been  discussed  in  the  chapter  on  the  range  and  distribution  of  the 
graptolites  [p.503]. 

Remarks.  The  dimensions  and  angles,  as  well  as  the  general  structure 
of  the  Deep  kill  specimens,  agree  closely  with  those  given  in  the  descrip¬ 
tions  of  the  Australian  and  Canadian  types,  leaving  no  doubt  of  the 

specific  identity  of  the  forms.  At  the  same  time  the  Australian  specimens 
are  reported  to  have  40  branches,  the  Canadian  types  even  attain  as  many 
as  80,  while  none  from  the  Deep  kill  have  been  observed  to  have 
developed,  even  in  large  specimens,  more  than  24,  or  six  on  each  stem. 
Though  the  fact  is  now  well  established  that,  in  the  multiramous 
dichograptids,  the  number  of  branches  furnishes  no  criterion  for  generic  dis¬ 
tinctions,  it  is  also  proved  that  in  the  phylogeny  of  this  group  there  can 
be  recognized  a  tendency  to  reduce  the  number  of  branches  and  to  attain 
a  fixed,  though  restricted  number.  In  this  process  the  Deep  kill  forms 
seem  to  have  reached  a  stage  *  beyond  that  of  the  more  multiramous 
Canadian  and  Australian  forms.  The  writer  proposed  in  a  former  paper 
[1902,  p.580]  to  designate  this  stage  by  the  varietal  name  postremus. 

In  the  paper  mentioned  it  has  been  demonstrated  by  means  of  the 
numerous  growth  stages  of  this  species  found  at  the  Deep  kill,  which 
furnish  an  unbroken  series  [pi. 6,  fig.l— 10  of  this  memoir],  that  the  “funicle” 
consists  of  two  thecae,  formed  by  dichotomous  branching  from  the  sicula, 


624 


NEW  YORK  STATE  MUSEUM 


and  that  also  the  stem  internodes  between  two  bifurcations  consist  of  but 
one  theca  each ;  that  hence  the  entire  rhabdosome  from  the  sicula  on  is 
built  up  of  thecae;  and  that  there  are  no  indenticulate  branches.  There 
exist  however  morphologic  and  functional  differences  between  the  earliest 
thecae,  which  are  constituent  parts  of  the  stems  and  the  later  thecae  of  the 
branches,  differences  which  also  appear  within  the  denticulate  branches 
themselves.  These  differences  were  held  to  indicate  ontogenetic  stages  of 
the  nature  of  those  which  have  been  termed  “  localized  ontogenetic  growth 
stages  ”  by  Jackson.  Here  the  localization  appears  in  so  far  as  each  branch 
passes  in  the  shape  and  arrangement  of  its  thecae,  like  an  organ  of  the 
whole  rhabdosome,  through  ontogenetic  stages,  indicative  of  phylogenetic 
or  evolutionary  stages  passed  by  the  species. 

A  single  specimen  [pi. 6,  fig.14]  was  obtained  which  had  not  been 
spread  out  like  the  others  on  the  bottom  of  the  sea,  but  became  compressed 
laterally.  This  shows  that  all  branches  were  held  in  a  nearly  horizontal 
position,  curving  slightly  upward  in  the  distal  parts1;  and  that  the  thecae 
pointed  all  in  one  direction,  viz  downward,  assuming  the  suspended 
position  of  the  rhabdosome.  Another  specimen  has  been  figured  here 
because  it  exhibits  an  abnormal  irregular  branching  on  one  (left)  side 
[pl.6,  %•  15]. 

Fragments  of  rhabdosomes  which  have  been  stripped  of  a  part  of 
their  branches,  are  liable  to  assume  very  misleading  aspects.  Specially 
numerous  were  specimens  retaining  only  four  branches,  in  such  a  manner  as 
to  suggest  a  Tetragraptus  [pl.6,  fig.  13].  These,  then,  in  the  character  of  their 
branches  and  thecae,  are  somewhat  similar  to  Tetragraptus  hicksii 
Hopk.  &  Lap.  [1875,  p.651],  a  species  which  has  lately  been  recognized  to  be 
based  on  a  bundle  of  rhabdosomes  of  an  Azygograptus. 


1  The  drawing  has  been  inverted  by  mistake. 


GRArTOLITES  OF  NEW  YORK,  PART  1 


G25 


Goniograptus  perflexilis  sp.  nov. 

Plate  6,  figures  16-18 ;  plate  7,  figures  1-9 

Goniograptus  sp.  nov.  Kuedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.556 

In  the  two  lowest  graptolite  horizons  of  the  Deep  kill  section  occur 
two  closely  allied  species  of  very  delicate  multiramous  dichograptids  which 
unite  the  mode  of  branching  characteristic  of  Goniograptus  with  the 
diverging  of  the  primary  thecae  from  a  point  close  to  the  apical  end  of  the 
sicula,  peculiar  to  the  coenograptids.  The  type  occurring  in  the  Tetragraptus 
horizon  is  the  one  described  here. 


Fig.  39  Goniograptus  p  er  f  1  e  x  i  1  is  sp.  nov. :  a  Sicula  and  first  theca.  7x;b  Growth  stage  of 
rhahdosorae  with  two  first  thecae.  Obverse  view.  x7 ;  c  Similar  stage.  Keverse  view.  x7 ;  cl  Further 
enlargement  of  proximal  parts  of  first  two  thecae.  x21.  Deep  kill 


Description.  Sicula  extremely  long  and  slender  (4  mm  long  and  but 
.  3  mm  wide),  the  first  thecae  originating  close  to  the  apical  point  of  the  sicula 
[fig.39],  and  adhering  to  the  latter  for  a  very  short  distance  and  then  pro¬ 
ducing  a  second  theca ;  both  first  and  second  thecae  diverging  from  the 
sicula  at  right  angles ;  these  thecae  but  little  shorter  than  the  sicula  and 
equally  narrow,  straight  or  slightly  curved,  with  the  convex  side  directed 
downward  ;  each  of  these  thecae  producing  again  two  thecae,  which  together 
form  an  angle  of  80°.  The  resulting  thecae  form  the  bases  of  the  four 
principal  stems,  which,  hence,  diverge  at  an  angle  of  80°  and  which, 
as  in  the  type  species  of  the  genus,  give  off  undivided  branches  alternately 
on  opposite  sides  from  the  outer  points  of  the  angles  of  their  zigzag 
shaped  course.  The  stem  divisions  form  an  angle  of  160°  with  each 


020 


NEW  YORK  STATE  MUSEUM 


Fig.  40  Goniograptus  perflexilis  sp.  nov. 
Enlargement  of  a  part  of  the  specimen  reproduced 
on  plate  7,  figure  9,  to  show  the  composition  of  the 
steminternodes  of  thecae  and  the  character  of  the 
thecae.  Deep  kill.  x2.5 


other ;  the  branches  leave  the  stems  with  an  angle  of  about  80°.  The 
branches  are  extremely  slender,  their  maximal  width  observed  being  only 
.  4  mm.  The  total  length  attained  by  the  branches  and  the  diameter  of 
the  whole  rhabdosome  are  not  known.  Six  branches  have  been  observed 
on  principal  stems  which  were  not  perfect.  The  thecae  are  extremely  nar¬ 
row,  long  and  tubular,  8  mm  long,  increasing  to  5  mm  in  the  distal  stem 

sections ;  in  the  mature  branches  about 
six  times  as  long  as  wide ;  in  contact 
more  than  one  half  of  their  length, 
numbering  not  more  than  6  to  7  in  10  mm, 
and  forming  an  angle  of  but  5°  with  the 
axis  of  the  branch.  They  have  gently 
concave  outer  margins,  nearly  straight, 
reflexed  apertural  margins,  which  form  an  angle  of  60°  with  the  axis  of 
the  branch. 

Position  and  localities.  In  graptolite  bed  2,  forming  the  upper  part 
of  the  Tetragraptus  horizon  in  the  Deep  kill  section,  and  rarely  also  in 
the  next  horizon.  While  younger  growth  stages  were  found  very  frequently, 
mature  colonies  are  extremely  rare  in  this  material.  One  large  fragment 
referable  to  this  species  [pl.6,  fig.  16]  was  obtained  from  the  beds  at 
Mt  Moreno  near 
Hudson  which  are 
transitional  from 
the  horizon  with 

Didy  mograptus  b  i  f  i  d  u  s  to  that  with  Diplograptus 
dentatus,  so  that  this  species  ranges  from  the  second  to  the  lower 
part,  at  least,  of  the  fourth  horizon. 

Pemarhs.  This  species  is  at  once  distinguished  from  G .  thureaui 
by  its  extremely  slender  habit,  the  narrow  branches  and  longer  thecae,  the 
less  angular  nature  of  the  principal  stems,  which  more  approach  to  a  straight 
line.  In  the  location  of  the  budding  and  diverging  points  of  the  thecae,  form¬ 
ing  the  “funicle”  it  differs  markedly  from  the  type  species  of  the  genus 


Fig.  41  Goniograptus  perflexilis  sp.  nov.  Enlargement  of  branch  of 
the  specimen  reproduced  on  plate  6,  figure  17.  Deep  kill.  x5.25 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


627 


and  all  other  multiramous  dichograptids  known  to  the  writer,  in  having 
these  points  close  to  the  apical  end  of  the  long  sicula.  It  has  been  noted 
in  the  chapter  on  the  phylogeny  of  the  dichograptids  [p.561]  that  this 
is  one  of  a  number  of  characters  which  indicate  a  connection  of  this 
species  with  a  separate  phylogenetic  series  of  forms,  ending  in  the  coeno- 
graptids.  A  form  presumably  derived  from  this  species,  described  here  as 
Sigmagrapt  us  prae cursor, 
differs  only  in  the  formation  of 


Fig.  42  Goniograptus  perflexilis  sp.  nov. 
Enlargement  of  portion  of  branch  of  the  specimen 
reproduced  on  plate  7,  figure  7.  Deep  kill.  x7 

left  and  upper  right  principal  stems  of  G,  perflexilis  into  nondividing 
branches  would  directly  lead  to  that  type. 

A  peculiar  feature  of  the  largest  specimen  figured  is  a  large,  chitinous 
body,  suggesting  a  collapsed  bag,  adhering  to  the  initial  part  of  the  rhabdo- 
some  [pi. 7,  fig.9].  Whether  this  distinctly  outlined  structureless  body  is  the 
remains  jf  a  central  disk  or  of  an  unknown  parasitic  growth,  it  is  impossible 
to  decide  by  means  of  a  single  specimen.  A  central  disk  of  the  alate  char¬ 
acter  observed  in  G.thureaui  has  not  come  to  observation  in  this  species. 

The  specimen  obtained  from  the  beds  at  Mt  Moreno  [pi. 6,  fig.  16],  if 
indeed  belonging  to  this  species,  presents  an  extreme  development  of  the 
flexible  or  flaccid  character  of  the  branches  of  the  species.  It  has  there* 
fore  been  distinguished  as  mutatio  flaccida.  The  apertures  of  its  hairlike 
thecae  are  2 . 5  mm  apart  and  the  thecae  appear  to  be  in  contact  not  more 
than  one  fourth  of  their  length. 

Goniograptus  geometricus  sp.  nov. 

Plate  7,  figures  10-20 

Cf.  Thamnograptus  anna  Hall.  Geol.  Sur.  Can.  Canadian  Organic  Remains, 
decade  2.  1865.  p.141,  pl.21,  fig.9 

Goniograptus  sp.  nov.  Ruedemann.  N.  Y.  State  Raleontol.  An.  Rep’t.  1902. 
p.566 

A  surface  of  graptolite  bed  3,  belonging  to  the  horizon  with  Didymo- 
graptus  b i f  i d  u  s ,  is  entirely  covered  with  the  rhabdosomes  of  an 


two  instead  of  four  principal  stems ; 
and  the  development  of  the  lower 


G28 


NEW  YORK  STATE  MUSEUM 


extremely  delicate  multiramous  dichograptid,  but  owing  to  their  flexible 
nature  the  branches  of  the  rhabdosome  have,  even  by  a  very  gentle  cur¬ 
rent,  nearly  always  been  drifted  into  an  inextricable  mass;  and,  as  at  the 
same  time  innumerable  specimens  are  piled  together,  it  was  found  impos- 


Fig.  43  Goniograptus  geoiuetricus  sp.  now  a  Sicula  and  proximal  parts  of  first  two  thecae. 
Shows  nema,  which  has  become  too  thick  in  the  zincograph.  x8;  b  Growth  stage  with  two  thecae,  which 
show  apertural  processes.  x7 ;  c  Like  growth  stage,  where  the  first  theca  originates  nearer  to  the  apex. 
x“ ;  (I  Growth  stage  in  which  the  first  theca  buds  extremely  close  to  the  apex  of  the  sicula  and  further 
dichotomy  has  set  in.  Reverse  view.  x7 ;  e  Young  rhabdosome  with  relatively  short  or  fragmentary  sicula. 
Reverse  view.  x7;  /  Greater  enlargement  of  first  dichotomy.  x21.  Deep  kill 


sible  to  obtain  specimens  as  well  spread  out  as  tlie  type  species  of  Gonio¬ 
graptus  has  furnished. 

Description.  Sicula  long  and  narrow,  needlelike,  with  an  average  length 
of  3.5mm,  but  only  a  maximal  width  of  .35mm;  in  some  instances  pro¬ 
vided  with  a  long,  very  fine  nema  [fig.43a|.  First  theca  budding  within 
the  apical  fourth  of  the  sicula;  this  and  the  second  theca  diverging  at  a 
point  one  fourth  of  the  length  of  the  sicula  from  the  apical  end  in  opposite 
directions  and  at  right  angles  with  the  sicula.  These  first  thecae  are  fili¬ 
form  (about  2  mm  long),  their  free  portions  mostly  straight,  but  often 
curved  upward.  The  secondary  thecae  (forming  the  branches  of  the  second 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


629 


order),  which  equal  the  primary  in  length  and  width,  diverge  under  angles 
of  120°  to  150°;  the  four  principal  stems  describe  a  zigzag  line,  the  sections 
of  which  form  an  angle  of  150°.  The  undivided  denticulate  branches 
stand  at  nearly  right  angles  to  the  general  direction  of  the  principal 
stems.  The  thecae  of  the  branches  are  tubular,  narrow,  about  2  mm  long, 
three  times  as  long  as  wide,  one 
fourth  to  one  third  of  their  length 
in  contact,  numbering  8  in  10  mm, 
their  outer  margins  nearly  straight 
or  slightly  concave,  the  apertural 
margin  straight  and  at  right  angles 
to  the  axis  of  the  theca,  inclined 
10°  to  the  axis  of  the  branch.  Total 
number  of  branches  40  or  more ; 
their  length  at  maturity  30  mm  or 
more.  Central  disk  not  observed. 

Position  and  localities.  Extremely 
common  at  the  Deep  kill  in  a  layer  of  the  horizon  with  Didymograptus 
b  i  f  i  d  u  s  ,  but  already  beginning  in  the  preceding  horizon. 

Remarks.  This  species  is  closely  related  to  the  preceding  one  which 
occurs  in  the  underlying  horizon,  differs,  however,  from  it  by  the  shorter 
length  of  the  sicula  and  thecae,  the  very  different  angle  of  divergence 
and  more  compact  arrangement  of  the  branches.  By  the  greater  angularity 

of  the  zigzag  shaped 
principal  stems,  it 

Fig.  45  Goniograptus  geometrieus  sp.  uov.  Fragment  of  a  branch.  resembles  lUOl'e  tile 
Deep  kill.  x5.25  •  <<  ,  i 

type  species  ot  tne 

genus  than  the  foregoing  species ;  but,  like  the  latter,  it  differs  from 
that  species  by  the  subapical  budding  point  of  the  primary  thecae  at  the 
sicula. 

I  have  little  doubt  that  the  specimen  on  which  Hall  based  his  species, 
Thainnograptus  anna,  was  a  branch  of  this  or  a  very  similar 


Fig.  44  Goniograptus  geometrieus  sp.  nor. 
Further  enlargement  of  the  specimen  reproduced  on 
plate  7,  figure  12  to  show  the  thecae  forming  the 
branches  of  the  first,  second  and  third  orders.  Deep 
kill.  x5.25 


was  a 


630 


NEW  YORK  STATE  MUSEUM 


species  of  Goniograptus,  for  it  agrees  in  tlie  zigzag  form  of  the  principal 
stem  and  the  inclination  of  the  branches  fully  with  that  delicate  Gonio- 
graptus.  The  similarity  is,  in  fact,  so  great  that  I  did  not  hesitate  at  the 
preliminary  identification  of  the  Deep  kill  fauna  to  refer  the  numerous 
fragmentary  branches  ofG.  geometricus,  occurring  in  that  locality, 
to  Thamnograptus  anna  [1902,  p.566].  As,  howmver,  Hall 
expressly  states  that  the  branches  of  his  species  are  filiform  and  do  not 
show  any  thecae,  while  those  of  G.  geometricus  were  found  to  bear 
distinct  and  prominent  thecae,  I  did  not  feel  justified  to  compare  my  material 
any  longer  with  that  species.  It  is  however  quite  possible  that  in  the  type 
specimen  of  Thamnograptus  anna  the  branches  expose  only  their 
dorsal  sides  and  for  this  reason  do  not  show  any  thecae. 

LOGANOGRAPTUS  Hall.  1867 

The  genus  Loganograptus  was  erected  by  Hall  and  separated  from 
the  large  generic  group  Dichograptus  Salter  for  the  reception  of  the  single 
species  Grap.tolithus  1  o  g  a  n  i  Hall,  and  described  [1867,  p.226]  by 
its  author  as  being  characterized  by  having  its  “  polypary  consisting  of 
more  than  eight  simple  stipes  proceeding  from  a  single  axis,  with  a  distinct 
broad  corneous  disc.”  The  genus  is  well  defined  and  readily  distinguished 
from  the  multiramous  Clonograpti  by  its  “  simple  stipes,”  resulting  from  the 
concentration  of  the  dichotomy  in  the  proximal  region,  and  by  the  secondary 
disk.  It  is  howmver  connected  by  transitions  so  closely  with  Dichograptus 
s.  str.  as  represented  by  Dichograptus  octobrac hiatus,  that 
these  two  groups  have  been  united  by  several  authors  (Herrmann,  Freeh) 
under  Dichograptus. 

But  as  each  of  these  genera  represents  characteristic  and  important 
phylogenetic  stages,  which  require  recognition,  they  are  retained  here. 
Dichograptus  s.  str.  marks  that  stage  in  the  phylogenetic  series  leading 
from  the  multiramous  forms  to  Tetragraptus,  where  the  decline  in  the  power 
of  dichotomy  has  proceeded  so  far  that  branches  of  three  orders  only  can 
be  produced,  the  highest  possible  number  of  branches  being  then  eight ; 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


631 


and  Loganograptus  denotes  tlie  preceding  stage  where  the  unlimited  for¬ 
mation  of  branches  in  Clonograptus  has  become  normally  restricted  to  those 
of  four  ord-ers  only.  Normally  a  Loganograptus  has  hence  16  branches; 
but  imperfect  fixation  to  branches  of  four  orders  on  one  hand,  and  incipient 
reduction  to  lower  orders  of  branches  on  the  other  cause  considerable 
variation  in  the  number  of  branches.  Thus  in  our  material  of  L.  logani 
there  occur  specimens  with  as  many  as  25  branches,  there  still  being  present 
branches  of  the  fifth  order,  while,  on  the  other  hand,  Elies  and  Wood 
mention  specimens  of  the  same  species  with  but  six  branches  where  only  one 
fourth  dichotomy  has  taken  place. 


Loganograptus  logani  Hall 

Plate  9,  figures  3-6 

Graptolithus  logani  Hall.  Geol.  Sur.  Can.  Rep’t.  for  1857.  1858.  p.115 
Graptolithus  logani  Hall.  Canadian  Organic  Remains,  decade  2.  1865.  p.100, 
pl.9,  fig.1-9  ;  pl.ll,  fig. 7 

Loganograptus  logani  Hall.  N.  Y.  State  Cab.  Nat.  Hist.  20th  An.  Rep’t. 
1867.  p.226 

Dichograptus  logani  Nicholson.  Quar.  J our.  Geol.  Soc.  1868.  24:128 

Loganograptus  logani  Nicholson.  Monogr.  Brit.  Grapt.  1872.  ptl,  p.109,  . 
fig.52c,  p.110 

Graptolites  (Didymograpsus)  logani  McCoy.  Geol.  Sur.  Victoria. 

Frodr.  Pal.  Victoria,  decade  1.  1874.  p.19 

?Loganograptus  logani  Etheridge  jr.  Ann.  and  Mag.  Nat.  Hist.  ser.  4.  1874. 

14:4,  pl.3,  fig.12 

Non  Loganograptus  logani  Etheridge  jr.  Ibid,  pl.3,  fig.ll  (  =  Gonio- 
graptus  thureaui) 

Dichograptus  logani  Herrmann.  Geol.  Mag.  Dec.  3,  1886.  3:24 

Cf.  Dichograptus  kjerulfi  Herrmann.  Geol.  Mag.  ser.  3.  1886.  3:22,23, 

fig-8 

Loganograptus  logani  Ami.  Geol.  Sur.  Can.  Rep’t.  ser.  2.  1889.  v.3,  pt2, 

p.H7k 

Dichograptus  logani  Matthew.  Roy.  Soc.  Can.  Proc.  and  Trans.  1893. 
11:114 

Loganograptus  logani  Gurley.  Jour.  Geol.  1896.  4:294 


632 


NEW  YORK  STATE  MUSEUM 


Dichograptus  logani  Eoeraer  &  Freeh.  Lethaea  palaeozoica.  1897.  1:595, 
fig. 162 

Loganograptus  logani  Elies.  Quar.  Jour.  1898.  54:476 

Loga-Dograptus  logani  Ruedemann.  N.  Y.  State  Palfeontol.  An.  Rep’t.  1902. 
p.556,  570 

Loganograptus  logani  Elies  &  Wood.  Monogr.  Brit.  Grapt.  ptl.  Pal.  Soc. 
for  1902,  p.81,  pi. 11,  fig.la-g 

Description.  Sicula,  nema  and  primary  disk  not  observed.  Rliabdo- 
some  consisting  of  relatively  long  (about  2.1mm)  branches  of  the  first 
order  (funicle),  dividing  dichotomously  into  four  short  branches  of  the  second 
order  (about  1.4  mm  long).  Twice  repeated  dichotomous  division  in  equally 
short  intervals  leads  normally  to  10  branches  of  the  fourth  order.  Sup¬ 
pression  of  one  or  the  other  of  the  third  dichotomies,  or  the  appearance 


Fig.  46  Loganograptus  logani  Hall.  Enlargement  of  branch.  Deep  kill.  x5.25 


of  fifth  dichotomies  on  some  of  the  branches  results  in  variations  in  the 
number  of  the  branches,  commonly  ranging  in  our  material  between  13  and 
25.  All  dichotomy  takes  place  within  5  mm  from  the  sicula,  or  Avitliin 
the  secondary  disk.  Branches  of  the  last  order  very  long  (7^  inches  and 
more  according  to  Hall).  Branches  straight,  narrow,  of  uniform  width 
(.8  mm  Avide).  Thecae  numbering  8  to  10  in  10mm,  short,  about  three  times 
as  long  as  wide,  in  contact  for  about  half  their  length,  inclined  at  30°,  their 
outer  margins  very  slightly  concave,  the  apertural  margins  straight  and 
inclined  to  the  axis  of  the  branch  under  an  angle  of  150°.  Large  secondary 
(central)  disk  present  in  larger  specimens. 

Position  and  localities.  In  graptolite  bed  2  (Tetragraptus  zone) 
occur  fragments  of  branches  which  may  belong  to  this  species,  but  no 
proximal  parts  were  noticed.  In  graptolite  bed  7  (zone  of  Diplo- 
g  r  a  p  t  u  s  d  e  n  t  a  t  u  s  )  were  found  the  specimens  reproduced  on  plate 
9,  figures  3-6.  Hall  reports  the  species  from  the  Point  Levis  beds;  but 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


633 


it  can  not  be  deduced  from  liis  work  whether  it  occurs  there  in  the  lower 
or  upper  zone.  Gurley,  however,  has  observed  it  only  among  the  grapto- 
lites  of  the  upper  Levis  zone,  hence  at  the  horizon  where  it  occurs  in  entire 
rhabdosomes  at  the  Deep  kill.  Ami  records  it  only  from  the  island  of 
Orleans,  in  an  association  insufficient  for  exact  determination  of  the  horizon. 
Matthew  found  it  in  division  3d  of  the  St  Johu  group  in  New  Brunswick. 
Nicholson,  and  Elies  and  Wood  have  described  it  from  the  Middle  Skid- 
daw  slates,  which  correspond  to  the  two  lower  zones  of  the  Deep  kill ;  while 
in  the  latter  place,  as  in  Canada,  it  may  be  restricted  to  a  higher  zone,  the 
Ellergill  beds  of  north  England.  In  Scandinavia  it  is  represented  by 
Dichograptus  kjerulfi  Herm.,  occurring  in  the  lower  Phyllograptus 
shales ;  and  in  Australia  it  has  been  recognized  by  McCoy  among  the 
graptolites  of  Castlemaiue  and  other  localities  of  the  province  of  Victoria 
(described  as  a  variety,  characterized  by  wider  branches  and  more  robust 
thecae). 

Remarks.  The  variability  of  the  number  of  the  branches  of  the  last 
order  in  this  species  and  its  bearing  on  the  phylogeny  of  the  Dicho- 
graptidae  have  been  discussed  elsewhere.  One  of  the  stages,  leading  from 
L.  logani  to  Dichograptus  octobrac hiatus,  in  which  the 
number  of  branches  had  been  at  least  locally  fixed,  is  that  represented 
by  Dich  ograptus  kjerulfi,  which  has  not  more  than  1 2 
branches. 

In  the  Deep  kill  section  the  species  rises  a  zone  higher  than  in  the  other 
localities,  from  which  it  has  been  known.  But  these  stragglers  have  the 
appearance  of  epacmic  mutations  of  the  species.  One  [pl.9,  fig.5]  is  so 
reduced  in  all  its  dimensions,  that  I  first  thought  it  to  be  a  new  species, 
but  now  consider  it  more  appropriate  to  distinguish  it  as  a  mutation,  viz 
L.  logani  mut.  pertenuis.  This  is  characterized  by  extremely  thin 
branches  (in  lateral  view  but  .6  mm  wide,  in  dorsal  view  .25  mm),  very  short 
thecae,  numbering  10  to  12  in  10  mm,  and  inclined  at  the  same  angle  as  in  the 
type  of  the  species. 


034 


NEW  YORK  STATE  MUSEUM 


dichograptus  Salter.  1863  (modified) 

The  genus  Dichograptus  was  erected  by  Salter  [1863,  p.139]  and 
defined  as  follows :  “  Frond  repeatedly  dichotomous  from  a  short  basal 

stipe  into  8,  16,  24  or  more  branches,  each  with  a  single  row  of  cells.” 
His  Dichograpsus  aranea,  being  the  first  form  figured,  would  be 
the  genotype,  but,  as  it  is  a  synonym  of  Hall’s  Graptolitlius  octo- 
brachiatus,  the  latter  becomes  the  type. 

Later  writers  have  successively  separated  groups  of  species  under  new 
generic  terms  from  the  assemblage  of  forms  embraced  by  Salter’s  definition, 
and,  following  Lapworth’s  and  Nicholson’s  example,  restricted  the  genus 
Dichograptus  to  forms  with  eight  branches  of  the  third  order,  with 
D.  octobrac hiatus  as  genotype.  Also,  Hall  used  the  term  in  this 
restricted  sense  [1863,  p.226].  Elies  [1898,  p.483]  and  Elies  and  Wood 
define  Dichograptus  by  the  restriction  of  the  formation  of  branches  to  that 
of  three  orders  [ see  under  Loganograptus,  p.630],  'which  gives  eight  branches 
as  the  maximal  number. 

As  there  are  several  species  (D.  octobrachiatus  Hall,  D  .  o  c  to¬ 
il  a  r  i  u  s  Hall  and  D.  separatus  Elies)  known  to  have  normally  branches 
of  three  orders,  this  stage  seems  to  be  important  enough  to  be  designated 
by  a  separate  name.  For  this  reason  we  also  use  here  the  term  Dichograptus. 
applying  it  in  its  restricted  sense.  The  fact,  however,  that  D.  separatus 
belongs  clearly  to  another  evolutionary  series  than  the  other  two  species  here 
cited  [ see  Introduction,  p.559],  indicates  that  the  group  is  of  polyphyletic 
origin  and  not  of  generic  value. 

Dichograptus  octobrachiatus  Hall  (sp.) 

Plate  8,  fig-ures  1-7 ;  plate  9,  figures  1,  2 

Graptolitlius  octobrachiatus  Hall.  Geol.  Sur.  Can.  Rep’t  for  1857.  1858. 

p.122 

Dichograpsus  aranea  Salter.  Quar.  Jour.  Geol.  Soc.  1863.  19:137, 

%9,  10 


G R A PTOLITES  OF  NEW  YORK,  PART  1 


635 


Graptolithus  octobrac  hiatus  Hall.  Canadian  Organic  Remains,  decade  2. 
1865.  p.96,  pi. 7,  fig.1-7  ;  pi. 8,  fig.  1-4 

Dichograpsus  octobrachiatus  Nicholson.  Quar.  Jour.  Geol.  Soc.  1868. 
24:129,  pi. 5,  fig.l,  2 

Dichograptus  octobrachiatus  Nicholson.  Monogr.  Brit.  Grapt.  1872. 
p.107,  fig.50 

Graptolites  (Didymograpsus)  octobrachiatus  McCoy.  Geol .  Sur. 

Yictoria.  Prodr.  Pal.  Victoria,  decade  1.  1874.  p.17,  pi. 2,  fig.4 

Loganograptus  kjerulfi  Herrmann  {ex  parte)  Nyt  Mag.  Nature.  1882. 
27:341-62 

Dichograptus  octobrachiatus  Brbgger.  Die  silurischen  Etagen  2  and  3. 
1882.  p.38 

Dichograptus  octobrachiatus  Herrmann.  Nyt  Mag.  Naturv.  1885. 
29:124 

Dichograptus  octobrachiatus  Herrmann.  Geol.  Mag.  Dec.  3,  1886.  3:22, 
fig-7 

Dichograptus  octobrachiatus  Lecrenier.  Ann.de  la  Soc.  Geol.  de  Belg. 
1887.  14:182 

Dichograptus  octobrachiatus  et  hexabrachiatus  Malaise.  Ann.  de  la 
Soc.  Geol.  de  Belg.  1888.  15:40-44 

Dichograptus  octobrachiatus  Ami.  Geol.  Sur.  Can.  Rep’t,  ser2.  1889. 
v.3,  pt2,  p.H7k 

o 

Dichograptus  octobrachiatus  Tomquist.  Lunds  Univ.  Arsskrift.  1891. 
26:12,  pi.  1,  fig.l 

Dichograptus  octobrachiatus  Gurley.  Jour.  Geol.  1896.  4:294 
Dichograptus  octobrachiatus  Roemer  &  Freeh.  Lethaea  palaeozoica. 
1897.  '  1:595 

Dichograptus  octobrachiatus  Elies.  Quar.  Jour.  Geol.  Soc.  1898. 
54:483 

Dichograptus  octobrachiatus  Ruedemann.  N.  Y.  State  Paleontol.  An. 
Rep’t.  1902.  p.  554,556 

Dichograptus  octobrachiatus  Elies  &  W ood.  Monogr.  Brit.  Grapt.  ptl . 
Pal.  Soc.  for  1902.  1902.  p.77,  pi. 9  ;  pi. 10,  fig.la-e 

Description.  Nema  and  primary  disk  not  observed.  Sicula  apparently 
short  and  stout  (about  1 .1mm  long).  Rhabdosome  consisting  of  branches  of 
three  orders,  those  of  the  first  order  (funicle)  together  about  2  mm 
long,  dividing  dichotomously  at  either  end.  The  four  branches  of  the 


NEW  YORK  STATE  MUSEUM 


630 

second  order  measure  1 . 5  mm  each.  The  latter  produce  normally  by 
dichotomy  eight  branches  of  the  third  order,  which,  in  the  vertically  com¬ 
pressed  condition  of  the  fossils,  are  straight,  equidistant,  very  robust 
(maximum  width  of  3.6mm  observed),  and  attain  a  length  of  10cm 
(probably  still  much  more,  as  indicated  by  separated  branches).  Thecae 
numbering  18  to  20  in  10  mm  on  large  branches,  and  20  to  22  in  the  same 
distance  of  more  proximal  portions,  not  quite  four  times  as  long  as  wide, 
in  contact  two  thirds  of  their  length,  inclined  at  their  bases  at  an  angle 
of  about  20°,  but  curving  so  that  near  the  aperture  the  outer  margin  forms 
an  angle  of  50°  to  55°  with  the  axis  of  the  branch ;  apertural  margin 
straight  or  concave,  forming  an  angle  of  105°  to  110°  with  the  axis  of  the 
branch. 

Adolescent  and  mature  colonies  possess  mostly  a  secondary  disk, 
extended  between  and  slightly  decurrent  along  the  branches.  It  is  roughly 
proportional  in  size  to  that  of  the  rhabdosome  and  attained  a  diameter  of  3 
to  4  cm. 

Position  and  localities.  At  the  Deep  kill  common  in  the  Tetragraptus 
horizon  (very  rare  in  graptolite  bed  1,  but  very  common  in  graptolite  bed  2), 
rare  in  the  zone  with  Didymograptus  bifid  us  (graptolite  bed  3). 
In  the  last  zone  (zone  of  D  i  p  1  o  g  r  a  p  t  u  s  dentatus,  graptolite  bed  7) 
only  a  single  specimen  of  the  hexad  type  [pl.8,  fig.6]  was  observed.  Hall’s 
types  came  from  the  Point  Levis  shales,  where,  according  to  Gurley’s 
observations,  this  species  occurs  only  in  the  Main  Point  Levis  zone  (Tetra¬ 
graptus  zone).  It  is  also  found  frequently  in  the  Middle  Skiddaw  slates 
(Dichograptus  beds)  of  north  England  and  south  Wales,  the  Phyllograptus 
shales  of  Christiania,  Norway  [Brogger  &  Herrmann],  and  of  Dalarne, 
Sweden  [Tornquist],  and  in  Belgium  [  Lecrenier,  Cluysenaar  and  Malaise]; 
and  McCoy  records  it  as  common  at  various  places  in  Victoria, 
Australia. 

Remarks.  This  stately  and  regularly  built  graptolite  was  first  de¬ 
scribed  by  Hall.  Salter  soon  after  termed  two  octobrachiate  forms  from 


GRAPTOLITES  OF  NEW  YORK,  FART  1 


637 


the  Skiddaw  slates  Dichograpsns  aranea  and  D.  sedge  wickii. 
We  agree  with  Elies  and  Wood  in  considering  the  first  of  these  names  as  a 
synonym  of  D  .  octobrachiatus,  the  differences  being  explicable  by  dif¬ 
ferent  modes  of  preservation. 

'Hall  noticed  already  that  the  number  of  branches  is  not  absolutely 
unvariable,  but  that  suppression  of  a  dichotomy  may  result  in  a  smaller 
number  of  branches.  Elies  mentions  a  septad  type,  where  one  branch  of 
the  second  order  fails  to  divide  dichotomously,  and  a  hexad  type,  where 
two  fail  to  divide.  The  only  specimen  of  the  hexad  type  noticed  in  our 
material  was  found  in  the  uppermost  Deep  kill  horizon  (with 
Diplograptus  dentatus),  where  the  Dichograpti  are  rapidly 
disappearing. 

Malaise  observed  a  hexabrachiate  form  in  Belgium  and  proposed  for 
it  the  specific  term  D.  hexabrachiatus  [loc.  cit.  p.44].  This  hexad 
variation  occurs  there  also  associated  with  octobrachiate  forms,  and  in  a  high 
zone  with  Didymograptus  murchisoni  and  Diplograptus 
pristiniformis  (=  dentatus),  as  in  New  York. 

These  occurrences  show  that  there  existed  a  tendency  to  reduction, 
which  has  finally  led  to  the  production  of  species  of  Tetragraptus 
[Introduction,  p.567]. 

On  the  other  hand  we  have  observed,  in  graptolite  bed  2,  a  form  with  nine 
branches  in  which  one  of  the  branches  of  the  third  order  has  divided  again 
dicbotomously,  thus  producing  two  branches  of  the  fourth  order  [pl.8,  fig. 7 ] . 
While  this  form,  by  the  strict  application  of  the  definitions  of  Logano- 
graptus  and  Dichograptus,  would  have  to  be  referred  to  the  former  stage,  it 
is,  in  the  character  of  the  thecae  and  branches,  and  its  general  habit, 
a  D.  octobrachiatus.  It  is  evident  that  hand  in  hand  with  the  reduc¬ 
tion  of  the  number  of  branches  other  changes  take  place  which  make  a  strict 
application  of  this  one  criterion  to  the  separation  of  the  species  impossible. 


038 


NEW  YORK  STATE  MUSEUM 


bryograptus  Lapworth.  1880 

The  genus  Bryograptus  was  erected  by  Lapworth  [1880,  p.164]  for 
forms  with  the  following  characters:  “polypary  bilaterally  subsymmetrical, 
consisting  of  two  compound  monoprionidian  branches  diverging  at  a  small 
angle  from  a  well  marked  sicula,  and  originating  similar  compound  (or 
single  ?)  secondary  branches  at  close  but  irregular  intervals  from  one  mar¬ 
gin  only.  Hydro  thecae  minute,  of  the  type  of  those  of  Dichograptus 
Salter.” 

This  genus  is  remarkable  for  two  facts,  the  irregularity  of  its  branch¬ 
ing  and  its  early  appearance.  These  facts  and  the  great  similarity  of  the 
species  of  Bryograptus  to  species  of  later  genera  with  more  regular  branching 
indicate  at  once  that  the  genus  is  a  synthetic  one,  and  stands  in  ancestral 
relation  to  various  simple,  more  regularly  branched  graptolites.  We  have 
discussed  these  relations  in  the  chapter  on  the  classification  and  phylogeny  of 
the  graptolites  [p.554],  to  which  we  refer  the  reader. 

Elies  and  Wood  have  divided  the  British  forms  into  two  series,  a  depen¬ 
dent  and  a  deflexed  series.  Each  of  these  is  represented  at  the  Deep  kill  by 
one  species. 

The  gemmation  of  the  first  thecae  could  be  observed  in  B .  lap- 
worth i  and  has  been  described  under  that  caption.  It  is  like  that  of 
other  Dichograptidae  and  specially  like  that  of  the  Didymograptidae.  The 
dichotomous  branching  also  takes  place  in  a  manner  identical  with  that 
described  by  the  writer  of  Goniograptus  thureaui  and  other 
Dichograptidae  [1902,  p.583],  viz  by  the  successive  budding  of  two  thecae, 
the  second  of  which  buds  from  the  first,  and  both  of  which  assume  diverging 
directions. 

The  genus  Bryograptus  can  be  said  to  hover  around  the  boundary 
line  between  Cambric  and  Siluric,  for  its  species  belong  all  either  to  the 
uppermost  Cambric  or  lowest  Lower  Siluric,  or  to  the  transitional  beds 
between  the  two,  as  B .  kjerulfi,  the  genotype  of  this  group,  in  the 
region  of  Christiania.  In  America  thus  far  only  some  forms  from  the 


ORAPTOLITES  OF  NEW  YORK,  TART  1 


639 


St  John  basin,  cited  here  under  Staurogr  apt  u  s  dichotomus  [p.614], 
have  been  referred  to  that  genus.  In  the  Deep  kill  beds  we  have  two 
new  species  termed  B .  pusillus  and  B .  lapworthi. 

It  is  a  remarkable  fact  that  the  genus  Bryograptus,  which  in  Sweden 
and  England  is  apparently  restricted  to  the  Upper  Cambric  beds1  and 
which  has  also  failed  to  be  observed  in  the  Canadian  Levis  beds,  corres¬ 
ponding  to  the  Deep  kill  horizon,  persists  here  in  the  Tetragraptus  beds 
with  two  species,  one  of  which  ( B .  pusillus)  is  extremely  rare,  while 
the  other  perfectly  covers  at  least  one  layer  and  is  also  quite  common  as 
a  component  of  the  typical  Tetragraptus  fauna  on  other  rock  surfaces  of  the 
same  bed. 


Bryograptus  lapworthi  sp.  nov. 

Plate  5,  figures  1-12 

Bryograptus  sp-  nov.  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.556 

Description.  The  rhabdosome  is  suspended  by  a  nema  often  relatively 
long,  and  very  thin.  This  has  in  several  cases  been  observed  to  be 
attached  —  in  one  case  by  means  of 
a  little  chitinous  node  [fig.12]  —  to 
small  chitinous  blotches,  supposed¬ 
ly  the  remains  of  a  primary  disk. 

The  sicula  is  of  medium  size  or 
rather  short  (1 . 2  mm  in  the  aver¬ 
age).  The  first  theca  originates 
close  to  the  apex  of  the  sicula, 
about  one  fourth  of  the  length  of 
the  sicula  from  the  same  [fig.47  |. 

This  first  theca  produces  the  second  one  close  to  its  own  initial  point  and 
both  these  primary  thecae  diverge  from  the  sicula  each  at  an  angle  of  about 
110°,  so  that  the  average  divergence  between  the  proximal  parts  of  the  result- 


1  One  exception,  that  of  a  species  of  B.  ramosns  var.  cumbrensis  on  a 
slab  with  Tetragraptus  bigsbyi,  is  noted  by  Miss  Elies  [1898,  p.472]. 


NEW  YORK  STATE  MUSEUM 


040 

ing  branches  is  about  140°  with  variations,  partly  perhaps  by  somewhat 
oblique  compression,  to  100°  on  the  one  and  to  170°  on  the  other  hand.  The 
branches  are  in  many  specimens  nearly  straight  in  the  initial  part,  in  the 
majority,  however,  they  have  a  slight  concave  curvature.  The  formation  of 
the  secondary  branches  [fig.7]  is  accomplished  like  that  of  the  primary  ones, 
by  rapidly  repeated  gemmation  [fig.ll].  The  secondary  branches  are  dis¬ 
posed  unsymmetrically,  as  the  figures  well  illustrate,  the  bifurcation  in  the 
rhabdosome  often  taking  place  in  one  branch  a  short  distance  from  the 
sicula,  in  the  other  very  distally  or  not  at  all.  In  no  case,  however,  has 
the  bifurcation  been  observed  so  close  to  the  sicula  as  in  B .  k  j  e  r  u  1  f  i , 
c a  1 1  a  v e i  or  r a m osus.  The  branches  are  very  slender,  their  maximum 
width  being  only  about  .  5  mm. 

The  thecae  are  long,  narrow  tubes  of  nearly  uniform  -width,  or  very 
slightly  widening  toward  the  aperture.  They  number  quite  constantly  10 
in  10  mm,  which  number  in  a  few  cases  sinks  to  9,  8  or  even  7 ;  they  are 
overlapping  one  third  to  one  half  of  their  length,  are  about  five  times  as 
long  as  wide  and  diverge  15°  to  20°  from  the  axis  of  the  branches. 
Their  outer  walls  are  straight  or  very  slightly  concave.  The  apertural  margins 
are  straight  and  form  an  oblique  angle  with  the  branch. 

Position  and  locality.  B .  lapworthiis  common  in  graptolite  bed 
1  and  very  common  in  graptolite  bed  2  of  the  Deep  kill  section. 

Pemarhs.  This  form  is  closely  related  to  the  specimen  from  the 
Lower  Skiddaw  slates  at  Barf,  doubtfully  referred  by  Marr  [1894,  p.130] 
and  Elies  [1898,  p.470]  to  B.  callavei  Lap  worth,  and  lately  described  by 
Elies  and  Wood  as  B.  divergens.  It,  however,  happens  so  that  one 
difference  between  the  specimen  mentioned  and  the  species  described  by 
Lapworth  is  here  still  more  emphasized,  i.  e.  the  branches  possess  a  still 
wider  divergence.  Moreover,  the  bifurcation  of  the  branches  in  none  of 
the  specimens  takes  place  so  near  to  the  sicula  as  in  the  specimen  from 
Barf  or  in  the  types  of  B.  callavei,  though  in  this  regard  a  great 
diversity  prevails  among  the  specimens,  as  is  evinced  by  the  figures 
[pi. 5,  fig.9, 10],  Our  form  differs  from  B.  divergens,  besides,  in  the 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


641 


wider  .angle  of  divergence  of  the  branches,  in  the  somewhat  closer  arrangement 
and  smaller  angle  of  inclination  of  the  thecae  ;  in  all  other  characters  it  agrees 
closely  with  that  form.  The  British  species  occurs  in  a  lower  horizon  than 
B .  lapworthi. 

Bryograptus  pusillus  sp.  nov. 

Plate  4,  figures  21, 22 

Bryograptus  k  j  e  r  u  1  f  i  (Lapworth)  Ruedemann.  N.  Y.  State  Paleontol.  An. 

Rep’t.  1902.  p.556 

This  species  is  represented  by  a  single,  well  preserved  specimen  found  on 
a  slab  from  graptolite  bed  2  (Tetragraptus  bed). 

Description.  Rhabdosome  small  (6  mm  long  excluding  the  nema) 
consisting  of  a  compact  group  of  dependent  branches.  It  begins  with  a 
long,  delicate  nema,  to  which  a  large  relatively  broad  sicula  (1  mm  long) 
is  attached.  From  this  originate  two  primary  branches  at  an  angle  of 
about  50°,  each  of  which  bifurcates  into  two  secondary  branches.  The 
innermost  of  these  divide  again  below  the  next  theca.  The  earlier  bifurca¬ 
tions  take  place  symmetrically.  The  thecae  which  are  disposed  along  the 
inner  margins  of  the  branches  are  long  and  narrow,  four  times  as  long  as 
wide,  slightly  curved;  they  number  10  in  10mm;  overlap  apparently  not 
more  than  one  fourth  of  their  length,  and  form  an  angle  of  about  15°  with 
the  axis  of  the  branch.  The  aperture  is  slightly  concave ;  the  apertural 
angle  has  not  been  accurately  determined,  but  is  larger  than  90°. 

Position  and  localities.  A  single  specimen  has  been  found  on  a  slab  of 
graptolite  bed  2  with  Tetragraptus  caduceus. 

Remarks.  This  form  in  its  habit  and  specially  in  its  mode  of  branch¬ 
ing  is  a  diminutive  example  of  B  .  k  j  e  r  u  1  f  i .  I  had,  for  this  reason, 
originally  referred  it  to  that  species,  considering  it  a  belated  mutation  of 
the  same  [1902,  p.556].  The  elaborate  descriptions  by  Miss  Elies  and 
the  exact  drawings  by  Miss  Wood,  however,  which  have  meanwhile 
appeared  in  the  Monograph  of  the  British  Graptolites,  allow  a  more  con¬ 
clusive  comparison  of  our  excellently  preserved  specimen  with  the  European 
material  of  B .  k  j  e  r  u  1  f  i .  By  this  we  find  that  it  differs  from  the  latter 


042 


NEW  YORK  STATE  MUSEUM 


in  having  the  thecae  a  little  closer  arranged,  narrower  and  smaller  and  less 
overlapping,  and  all  branches  narrower  and  diverging  more  from  each 
other  at  their  bases.  These  differences,  combined  with  the  fact  that 
B.  k  j  e  r  n  1  f  i  occurs  in  Europe  in  a  much  deeper  horizon  (Bryo- 
graptus  beds),  make  this  form  worthy  of  recognition  as  a  separate 
species. 

With  this  species  the  genus  Bryograptus  makes  its  last  appearance  in  the 
graptolite  beds  of  New  York. 

tetragraptus  Salter 

The  genus  Tetragraptus  was  proposed  by  Salter  [1863,  p.136]  for 
forms  in  which  “  bifurcation  takes  place  twice,  the  branches  patent  or 


Fig-.  48  Tetragraptus  si  mi  1  i  s  Hall  sp.  Early  growth 
stage  of  rhabdosome  etched  out  of  Vaginatenkalk  of 
Oeland :  a  Obverse  side  showing  sicula  and  first  theca. 
b  Reverse  side  showing  the  connecting  canal.  xl2  (Copies 
from  Holm) 

nearly  close.”  Thus  defined,  the  “  genus  ”  embraces  a  wide  range  of  forms, 
which,  as  noted  before  [p.554]  belong  to  different  phylogenetic  series  and  have 
closer  interrelations  with  species  of  other  “genera”  of  like  compass,  as 
Didymograptus  and  Bryograptus,  than  with  each  other.  The  term,  while 
eminently  useful  for  a  temporary  grouping,  is  but  an  expression  for  a  stage 
in  the  general  progress  of  the  class  of  graptolites  and  does  not  comprise 
a  natural  group  of  species  of  the  same  series.  The  genus  as  usually 
understood  is  hence  polyphyletic ;  and  should  be  subdivided  into  the 
natural  groups  quanti valent  to  a  genus.  The  entirely  different  thecal 
character  of  a  new  form,  [see  T .  1  e  n  t  u  s]  which,  under  the  present  system, 
atic  arrangement,  comes  under  Tetragraptus,  emphasizes  strikingly  this 
demand  of  recent  graptolithoiogy.  Such  a  grouping  has  been  attempted  by 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


643 


Elies  and  Wood.  These  authors  have  divided  the  species  according  to  the 
ultimate  direction  of  their  branches  into  series  groups,  some  of  which  fall 
again  into  groups  by  the  character  of  their  thecae.  In  applying  to  our 
species  of  Tetragraptus  this  system,  which,  according  to  present  knowledge, 
unites  the  members  of  phylogenetic  series  we  obtain  the  following  series 
and  groups. 

Horizontal  series . Group  1  ....  Type  T.  quadribrachiatus 

T.  quadribrachiatus 
T  .  a  m  i  i 


Dependent  series . 

. .  .Group  2.  . 

. .  . Type  T.  fruticosus 

T .  fruticosus 

T  .  c  1  a  r  k  e  i 

Group  3 . . . 

.  . Type  T.  pendens 

T. pendens 

Reclined  series . 

. . . Type  T  .  s  e  r  r  a 

T  .  s  e  rra 

Group  5 . . , 

. .  .  Type  T  .  similis 

T.  similis 

T  .  w  o  odi 

T.  pygraaens 

Group  6 . . . 

.  . Type  T.  taraxacum 

T.  taraxacum 

Flexuous  (Etagraptus)  series . . 

. . .  Group  7  - . 

, .  .  Type  T  .  lentus 

T .  lentus 

Holm  has  succeeded  in  isolating  the  rhabdosomes  of  a  species  of 
Tetragraptus  (T.  similis)  and  thus  demonstrated  that  from  the  sicula 
near  its  apex  originates  a  first  theca,  from  which  a  second  theca  buds  that 
turns  to  the  other  side.  The  development  up  to  this  stage  is  exactly 
homologous  to  that  in  Didymograptus.  In  e^ch  of  the  two  diverging  thecae 
a  dividing  wall  appears,  so  that  from  each  of  these  thecae  two  new 
thecae  are  originated.  Each  of  the  four  resulting  thecae  becomes  the  mother 
theca  of  a  branch.  We  have  copied  some  of  Holm’s  excellent  drawings  which 
illustrate  this  development  [text  fig.48-50]. 


644 


NEW  \Oi«K  STATE  MUSEUM 


Elies 


Fig-,49  Tetrag'i'aptns 
similis  Hall  sp.  Proxi¬ 
mal  part  of  a  rhabdosome, 
seen  from  the  left  side,  xfi 
(Copy  from  Holm) 


ojenus  which 

O 


and  Wood  assert  that  in  some  forms,  as  in  T.  quadri- 
brac hiatus,  the  earliest  thecae  remain  undivided, 
and  the  second  or  third  theca  on  each  side  of  the  sicula 
undergoes  division.  The  writer’s  material  corroborates 
this  statement,  the  correctness  of  which  is  already  sug¬ 
gested  by  the  greater  relative  length  of  the  branches  of 
the  first  order. 

We  append  here  the  description  of  a  proposed  sub¬ 
comprises  group  7. 

ETAGRA PTUS 1 


Plate  9,  figures  7-10 

The  rhabdosome  consists  of  two  short  central  branches  of  the  first 
order,  from  which  on  either  side  originate  two  branches  of  the  second 
order,  which,  diverging  in  opposite  directions  and  at  right  angles  from 
the  former,  appear  as  two  slender,  fiexuous  undivided  branches,  correspond¬ 
ing  to  the  vertical  lines  of  an  H,  while  the  primary 
branches  form  the  connecting  bar.  The  sicula  is 
long  and  the  primary  thecae  diverge  from  the  proxi¬ 
mal  part  of  the  same. 

This  group  has  the  same  structure  as  Tetra- 
graptus,  viz  a  twice  repeated  bifurcation.  It  is, 
however,  in  the  character  of  its  thecae,  the  point  of 
branching  of  the  primary  thecae  and  the  direction 
assumed  by  the  branches  of  the  second  order  totally 
different  from  the  other  species  of  Tetragraptus ; 
and  it  can  be  easily  proved  to  belong  to  an  entirely  different  series  from  the 
other  four  branched  forms  |  cli.10,  p.561].  The  very  slender  thecae,  the  result¬ 
ing  very  thin,  fiexuous  branches,  the  peculiarly  long  sicula  and,  specially,  the 
divergence  of  the  primary  thecae  at  a  point  high  up  near  the  apex  indi- 
dicate  that  T.  (Etagraptus)  lent  us,  the  type  of  the  subgenus 
belongs  in  one  group  with  Groniograptus  perflexilis,  is  closely 


Fig.50  Tetragraptus  similis 
Hall  sp.  Proximal  part  seen  from 
below.  Shows  the  apertures  of  the 
sicula  (in  the  center),  of  the  first 
two  thecae  and  of  those  of  the 
proximal  portions  of  the  branches. 
x6  (Copy  from  Holm) 


1  In  allusion  to  tlie  similarity  of  its  form  to  the  Greek  letter  II. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


645 


related  to  Sigmagraptus  praecursor  and  Coenograptus,  tliougli 
not  their  progenitor,  and,  very  probably,  leading  to  certain  flexuons  forms  of 
Didymograptus. 

Tetragraptus  quadribrachiatus  Hall  (sp.) 

Plate  11,  figure  1-4 

Graptolithus  quadribrachiatus  Hall.  Geol.  Sur.  Can.  Rep’t  for  1857. 
1858.  p.125 

Tetragrapsus  crucialis  Salter.  Quar.  Jour.  Geol.  Soc.  1863.  19:137, 

fig.  8b 

Graptolithus  quadribrachiatus  Hall.  Canadian  Organic  Remains,  decade  2. 
1865.  p.91,  pi. 5,  tig.1-5  ;  pi. 6,  fig.5,6 

Tetragrapsus  quadribrachiatus  Nicholson.  Quar.  Jour.  Geol.  Soc.  1868. 

24:131 

Of.  Graptolites  (Didymograpsus)  quadribrachiatus  McCoy.  Jour. 
Geol.  Sur.  Victoria.  Prodr.  Pal.  Victoria,  decade  1.  1874.  p.15,  pi. 2, 

fig-1 

Non  Tetragraptus  quadribrachiatus  Etheridge  jr.  Ann.  and  Mag.  Nat. 
Hist.  ser.  4.  1874.  14:3,  pi. 3,  fig.5-8 

Tetragrapsus  quadribrachiatus  Hopkinson  &  Lap  worth.  Quar.  Jour. 
Geol.  Soc.  1875.  31:649,  pl.33,  fig.9a,  9b 

Tetragraptus  quadribrachiatus  Linnarsson.  Sver.  Geol.  Und.  1879.  Afh. 
och  upps.  ser.  C,  no.31,  p.5 

Tetragraptus  quadribrachiatus  Brbgger.  Die  sil.  Etagen  2  and  3.  1882. 

p.38 

Tetragraptus  quadribrachiatus  Tomquist.  Sver.  Geol.  Und.  1883. 
Afh.  och  upps.  ser.  C,  no.57,  p.16 

Tetragraptus  quadribrachiatus  Herrmann.  Quar.  Jour.  Geol.  Soc.  1886. 
ser.  3,  3:18 

Tetragraptus  quadribrachiatu  s  Barrois.  Ann.  de  la  Soc.  Geol.  du  Nord. 

1892.  20:95 

Tetragraptus  quadribrachiatus  Matthew.  Roy.  Soc.  Can.  Trans,  and  Proc. 

1893.  11:114 

Tetragraptus  quadribrachiatus  Gurley.  Jour.  Geol.  1896.  4:295 
Tetragraptus  quadribrachiatus  Roemer  &  Freeh.  Lethaea  palaeozoica. 
1897.  1:603 

Tetragraptus  quadribrachiatus  Elies.  Quar.  Jour.  Geol.  Soc.  1898. 
54:485 


646 


NEW  YORK  STATE  MUSEUM 


Tetragraptus  quad  ribrac  hiatus  Ruedemann.  N.  Y.  State  Paleontol.  An 

Rep’t.  1902.  p.556 

Tetragraptus  quadribrachiatu  s  Elies  &  W  ood.  Monogr.  Brit.  Grapt.  ptl. 

1902.  p.57,  pi. 5,  fig.la-d 

Description,  Primary  disk  and  nema  not  observed.  Sicula  present, 
but  observed  only  in  sections.  Branch  of  first  order  2.6mm  long,  consist- 
ing  apparently  of  two  thecae  on  either  side.  Four  branches  of  the  second 
order,  which  are  spread  out  horizontally;  straight,  slender,  rigid,  increasing 

very  gradually  from  a  width  of  .  6  mm  to  one 
of  2.4  mm,  attaining  a  maximal  length  of 
42  mm.  Thecae  8  to  9  in  10  mm,  inclined  at  a 
low  angle  (about  35-40°),  narrow  (four  times 
as  long  as  wide),  overlapping  for  one  half  to 
one  third  of  their  length.  Outer  wall  slightly^ 
curved.  Apertural  margins  straight  or  slightly 
concave,  normal  on  the  axis  of  the  thecae. 

Position  and  localities.  In  the  Deep  kill 
section  this  species  has  been  found  in  great 
number  in  graptolite  bed  2  (Tetragraptus  zone),  less  common  in 
bed  5  and  in  but  a  single  specimen  in  graptolite  bed  7  (zone  with  Diplo- 
g  r  a  p  t  u  s  dentatus)1.  It  is  also  common  in  a  band  of  sandy  slate,  out¬ 
cropping  between  Defreestville  and  West  Sandlake,  Rensselaer  co.  N.  Y. 
[T.  N.  Dale,  coll.] ;  and  one  small  specimen  has  been  observed  in  the  shales 
with  Diplogra  p  t  u  s  dentatus  at  Mt  Moreno  near  Hudson  N.  Y. 

Hall’s  specimens  came  from  the  lower  shales  of  Point  Levis  (Tetra 
graptus  horizon  or  Main  Point  Levis  zone  of  Gurley).  Matthew  collected  it 
also  in  the  St  John  basin.  In  Great  Britain  the  species  occurs  in  the  mid¬ 
dle  and  upper  beds  of  the  Middle  Skiddaw  slates  in  the  Lake  district  at 
numerous  localities ;  in  the  St  David’s  district  in  Wales  and  in  the  Ballantrae 


Fig.  51  Tetragraptus  quadri- 
brachiatus  Hall  sp.  Young  rhabdo- 
some.  Deep  kill.  x4.5 


'The  latter  may  belong  to  a  somewhat  different  later  mutation,  as  the  greater 
proximal  width  of  its  branches  would  suggest,  but  it  is  not  in  a  sufficiently  good  state  of 
preservation  to  decide  this  point. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


647 


district  in  south  Scotland.  Brogger  records  it  from  the  region  of  Christiania, 
the  Swedish  authors  from  Dalecarlia  and  the  Tetragraptus  zone  in  Scania. 
Barrois  cites  it  as  being  rare  in  the  graptolite  schists  at  Cabrieres  in 
the  Languedoc,  and  McCoy  reports  it  from  the  shales  of  Victoria, 
Australia. 

Remarks.  Hall  said  of  this  species,  that  it,  “when  entire,  is  readily 
distinguished  from  Graptolithus  bryonoides  by  its  straight  and 
more  slender  branches,  and  by  the  general  aspect  and  expression  of  the 
fossil.”  Indeed,  the  geometric  regularity  of  the  disposition  of  the  branches 
in  the  compressed  material,  combined  with  their  slenderness,  will  readily  serve 
as  a  distinctive  character,  even  where  the  various  species  of  Tetragraptus  are 
promiscuously  mixed,  as  in  graptolite  bed  2.  On 
account  of  the  original  horizontal  position  of  the 
branches  and  the  downward  direction  of  the 
thecae,  with  rare  exceptions  only  the  dorsal  or 
ventral  side  is  exhibited,  and  the  profile  view  branch  enlarged.  Deeifkill.  x3.2 
can  be  observed  only  when,  as  in  the  original  of 

figure  3,  the  branches  wrere,  during  entombment,  turned  to  one  side.  Also 
on  account  of  this  position  of  the  rhabdosome  the  sicula  is,  ih  the  shale, 
always  embedded  in  its  natural  vertical  position  and  therefore  only  seen  in 
sections. 

The  horizontal  and  rigid  position  of  the  branches  is  evidently  largely  due 
to  the  character  of  the  dorsal  perisarcal  wall  of  the  coenosarcal  canal, 
which  in  the  flattened  specimens  alone  projects  bodily  and  appears  like  a  solid 
axis.  The  same  feature  is  found  still  more  emphasized  in  T.  amii,  evi¬ 
dently  on  account  of  its  broader  and  correspondingly  heavier  branches. 

Tetragraptus  amii  Lap  worth  ms.  (Elies  &  Wood  em.) 

Plate  11,  figures  5-7 

Graptolithus  bryonoides  Hall  (pars).  Geol.  Sur.  Can.  Grapt.  Quebec  Group. 

Figures  and  Descriptions,  decade  1.  1865.  p.84,  pi. 4,  fig.9,  10 

Tetragraptus  amii  Elles&Wood.  Monogr.  Brit.  Grapt.  1902.  ptl.  Pal.  Soc. 

p.60,  pi. 5,  fig.4a-c 


Pig.  52  Tetragraptus  quadri- 


048 


NEW  YORK  STATE  MUSEUM 


ilosome ;  one  branch  missing. 
Reverse  view.  Sliows  point  of 
origin  of  first  theca  and  direc¬ 
tion  of  proximal  portions  of 
branches.  Deep  kill.  x4. 


Description.  Primary  disk  and  nema  not  observed.  Sicula  incon¬ 
spicuous,  about  2  mm  long.  Branches  of  first  order  (consisting  of  one  theca) 
narrow  (.5mm),  3.1mm  long.  Four  branches  of  second  order  or  main 
stipes  disposed  horizontally,  having  a  normal  length  of  30  cm,  but  attaining 

a  maximal  length  of  60  mm  and  more ;  those  of  either 
side  forming  angles  ranging  between  70°  and  90°, 
widening  within  a  few  millimeters  from  the  point  of 
bifurcation  to  the  maximal  ividtli  (2 .9  to  3  mm), 
which  is  maintained  to  near  the  distal  end.  Thecae 
slightly  curved,  numbering  9  to  10  in  10  mm, 
about  3  mm  long,  inclined  at  40°  in  their  average, 
of  uniform  width,  three  to  four  times  as  long  as  wide, 
and  overlapping  about  three  fourths  of  their 
length.  Outer  walls  concave,  apertural  margin  concave,  normal  to  the  axis 
of  the  theca. 

Position  and  localities.  Hall  does  not  state  the  locality  of  the  specimen 
which  is  referred  by  Elies  and  Wood  to  their  new  species.  At  the  Deep 
kill  we  have  observed  this  form  only  in  graptolite  bed  2  (Tetragraptus 
zone),  where  it  is  found  associated  with  T.  serra,  T.  fruticosus, 
Phyllograptus  ilicifolius,  Didymograptus  extensus, 
etc.  The  authors  of  the  species  record  it  from 
the  Middle  Skiddaw  slates,  in  association  with 
some  of  the  species  just  mentioned;  and  from 
south  Wales. 

Remarks.  Elies  and  Wood  state  in  their 
work  that  this  form  was  included  by  Hall  (with 

doubt)  in  T .  b  r  y  o  n  o  ides  (  =  s  e  r  r  a)  ,  and  that  Lapworth  long  con¬ 
sidered  it  as  distinct.  Also,  the  present  writer  had  recognized  the  differences 
between  this  form  and  T.  serra,  when  the  description  of  the  species  was 
published.  While  the  dimensions  and  characters  of  the  branches  and  thecae 
are  the  same  as  in  T .  serra,  the  branches  are  here  disposed  horizontally, 
instead  of  being  reclined  as  in  that  form.  This  difference  is  most  strikingly 


Fig.  54  Tetragraptus  amii  L, 
E.  &  W.  Fragment  of  branch.  Deep 
kill.  x3.3 


GRAPTOLITES  OF  NEW  YORK.  TART  1 


(349 


shown  iii  the  numerous  young  specimens,  which  frequently  become  com¬ 
pressed  laterally.  In  this  mode  of  preservation,  in  T.  serra  the  four 
branches  diverge  fully  [pi.  11,  fig. 8] ;  while  in  T.  amii  they  coincide  more 
or  less  [pi. 11,  fig-7]. 

From  T .  quadribrachiatus,  which  possesses  the  same  horizontal 
disposition  of  the  branches,  this  species  is  readily  distinguished  by  the  rapid 
widening  of  the  branches. 

A  feature  still  more  distinctly  developed  in  this  species  than  in  the 
other  congeners  is  the  thickness  of  the  dorsal  wall  of  the  coenosarcal 
canal  [p.552,  pi.  11,  fig. 5]. 

Tetragraptus  fruticosus  Hall  sp. 

Plate  9,  figures  11-14;  plate  10,  figures  1-10 

Graptolithus  fruticosus  Hall.  Geol.  Sur.  Can.  Rep’t  for  1857.  1857. 

p.128 

Graptolithus  fruticosus  Billings.  Geol.  Sur.  Can.  Pal.  Foss.  1865. 
1:366,375 

Graptolithus  fruticosus  Hall.  Canadian  Organic  Remains,  decade  2.  1865. 

p.90,  pi. 5,  fig.6-8 

Graptolithus  fruticosus  Hall.  N.  Y.  State  Cab.  Nat.  Hist.  20th  An.  Rep’t. 
1867.  pl.3,  fig.  15 

Didymograptusl  fruticosus  Etheridge  jr.  Ann.  and  Mag.  Nat.  Hist.  ser.  4. 
1874.  14:6,  pl.3,  fig.  19 

Graptolites  (Didymograpsus)  fruticosus  McCoy.  Jour.  Geol.  Sur. 

Victoria.  Prodr.  Pal.  Victoria,  decade  1.  1874.  p.13,  pl.l,  fig  9-14 

Tetragraptus  fruticosus  Lapworth.  Ann.  and  Mag.  Nat.  Hist.  ser.  5.  1880. 

6:20 

Tetragraptus  (Bryograptus?)  fruticosus  Brogger.  Die  sil.  Etagen  2 
and  3,  etc.  1882.  p.39 

Tetragraptus  fruticosus  Tullberg.  Sver.  Geol.  Und.  1882.  Afh.  och 
upps.  ser.  C,  no.50,  p.22 

Tetragraptus  fruticosus  Lapworth.  Roy.  Soc.  Can.  Proc.  and  Trans.  1886. 

p.168 

Tetragrapsus  fruticosus  Ami.  Geol.  Sur.  Can.  Rep’t.  ser.  2.  1889.  v.3, 

pt2,  p.ll6k 

Tetragrapsus  fruticosus  Gurley.  Jour.  Geol.  1896.  4:295 


650 


NEW  YORK  STATE  MUSEUM 


Tetragraptus  f  r  u  t  i  c  o  s  u  s  Roemer  &  Freeh.  Lethaea  palaeozoiea.  1897.  Bdl, 

p.602 

Tetragraptus  fruticosus  Rnedemann.  N.  Y.  State  Paleontol.  An.  Rep’t. 

1902.  p.554,  556,  566  ;  p.588,  fig.15 

Tetragraptus  fruticosus  Elies  &  Wood.  Monogr.  Brit.  Grapt.  ptl.  Pal. 

Soc.  vol.  for  1902.  1902.  p.01,  pi. 6,  fig.2a,  b 

Description.  Sicula  long  (about  3 . 6  mm),  and  slender.  Provided  in 
young  colonies  with  a  short,  thin  nema  which  in  one  case  [pl.9,  fig.14]  has 
been  observed  to  terminate  in  a  small  concentrically  wrinkled,  chitinous  disk 
(diameter  =  1 . 3  mm).  Mature  rhabdosome  suspended  by  means  of  a  long, 
stout  nema,  or  nemacaulus,  which  attains  a  width  of  1 . 5  mm  (in  compressed 
state)  and  gradually  tapers  to  a  tine  thread.  Total  length  of  nema  unknown, 
but  in  a  mature  specimen  a  fragment  of  30  mm  in  length  has  been  observed, 
which  did  not  show  any  decrease  in  its  width.  First,  theca  budding  in  the 
apical  third  of  the  sicula ;  first  and  second  thecae  adhering  to  the  sicula  till 
near  its  aperture ;  each  of  these  thecae  producing  two  branches  by  dichotomy. 
Two  pairs  of  gracefully  and  symmetrically  curved  branches,  which  give  to 
the  rhabdosome  a  bell  or  lyre-shaped  outline ;  the  branches  attain  a  length  of 
10  cm  and  more,  and  a  width  of  3.5  mm,  and  diverge  at  an  angle  of  about 
40°.  The  reflection  of  the  branches  takes  place  at  various  distances  (18  to 
48  mm)  from  the  aperture  of  the  sicula.  The  branches  increase  gradually  in 
width  up  to  the  point  of  reflection,  when  they  become  approximately  uniform 
in  width.  Thecae  short  and  broad  in  the  proximal  parts  of  the  branches, 
long,  narrow  and  mucronate  in  the  mature  parts,  six  being  counted  in  the 
space  of  10  mm  in  the  former  and  eight  within  the  same  space  in  the  latter. 
The  early  thecae  overlap  about  one  half  their  length,  the  mature  ones  are  in 
contact  nearly  their  entire  length ;  the  former  form  an  angle  of  about  20° 
with  the  axis  of  the  stipe,  the  latter  one  of  40° ;  the  apertural  margins  of  the 
nepionic  thecae  are  straight,  their  upper  margin  is  not  protracted  into  a 
mucro,  while  the  apertural  margins  of  the  mature  thecae  are  deeply  concave 
and  their  upper  margins  mucronate. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


651 


Position  and  localities.  T.  fruticosus  has,  at  the  Deep  kill,  been 
collected  in  graptolite  beds  1  and  2.  In  both  beds  which  belong  to  the 
Tetragraptus  zone,  it  occurs  in  much  larger  specimens  than  have  been 
hitherto  recorded ;  and  with  the  forms  found  in  bed  2  it  reached  distinctly 
the  acme  of  its  development.  In  bed  3  (zone  with  Didy  mograptus 
b  i  f  i  d  u  s  and  Phyllograptus  anna)  it  is  not  found  any  longer 
at  the  Deep  kill  in  its  typical  development.  Hall  reported  the  form  from 
“  the  shales  of  the  Quebec  group  at  the  upper  end  of  Orleans  island,  and  three 
miles  above  river  St  Anne.”  Ami  records  it  from  three  localities  near  Levis, 
in  two  of  which  it  is  a  member  of  the  Didymograptus  bifidus  fauna,  while  in 
the  third  it  is  one  of  the  Tetragraptus  fauna.  Gurley  lists  it  as  occurring  in 
the  “  Main  Point  Levis  zone  ”  and  the  “  Phyllograptus  anna  zone,”  which 
range  tallies  with  that  at  the  Deep  kill  and  with  Ami’s  results.  Billings 
identified  graptolites  from  the  division  P  at  Cowhead,  Newfoundland,  with 
this  Quebec  species.  In  Britain  it  is,  according  to  Elles’s  reports  and  those  of 
the  monographers,  poorly  represented,  but  occurs  in  the  Arenig  of  south 
Scotland  and  of  the  Lake  district.  In  Sweden  and  Norway  it  is  found  in  the 
Phyllograptus  shale  ( fide  Tornquist,  Tullberg  and  Brogger) ;  in  Australia, 
McCoy  has  declared  specimens  from  various  outcrops  of  the  Lower  Siluric 
slate  in  Victoria  to  be  “  perfectly  identical  in  all  respects  with  the  North 
American  species.” 

Remarks.  From  the  figures  or  descriptions  furnished  by  the  authors, 
cited  above,  it  can  be  concluded  that  they  had  either  only  immature 
specimens  or  proximal  parts,  or  small  mutations  before  them.  As  our  series 
contains  excellent,  fully  developed  specimens  and  exhibits  division  into  two 
variations,  we  have  been  able  to  enlarge  the  original  description  considerably. 
The  difference  in  the  character  of  the  earlier  and  later  thecae  of  the  branches 
has  been  pointed  out  before  by  the  writer  [1902,  p.589],  and  its  phylo¬ 
genetic  significance  set  forth  [see  also  Introduction,  p.581]. 

In  the  Tetragraptus  bed  there  occur  two  greatly  differing  variations  of 
the  form,  which  however  are  sufficiently  connected  by  transitional  forms 
to  warrant  their  retention  within  the  bounds  of  one  species.  In  one,  the 


652 


NEW  YORK  STATE  MUSEUM 


more  common  form,  the  reflection  of  the  branches  takes  place  at  quite  a 
distance  from  the  sicnla,  or  initial  part  of  the  rhabdosome,  and  the  prox¬ 
imal  portion  of  the  branches  possesses  a  convex  outer  margin.  The  outline 
of  these  rhabdosomes  is  such  as  to  suggest  a  section  of  a  bell.  We  will 
therefore  designate  this  variety,  which  is  the  one  originally  observed  by  Hall, 
as  T .  fruticosus  campanulatus  [pl.10,  fig.7]. 

Very  different  in  habit  from  this  are  forms  which  the  writer  at  first 
believed  to  represent  a  different  species  [pi. 10,  fig.2].  The  proximal  parts  of 
their  branches  diverge  stronger,  are  concave  toward  the  outside,  and  the 
reflection  takes  place  considerably  earlier.  The  result  is  an  outline  suggestive 
of  a  trumpet ;  and  we  designate  this  variety  as  T  .  fruticosus  t  u  bi- 
formis.  This  variety  approaches  Didymograptus  V-fractus 
Salter  so  much  that  it  suggests  itself  as  the  progenitor  of  that  species. 

The  nema  or  nemacaulus  of  this  species  is  in  large  specimens  inflated  in 
the  middle  and  may  have  been  filled  with  gas  to  aid  in  supporting  the  stout 
rhabdosome. 

Tetragraptus  clarkei  sp.  nov. 

Plate  11,  figures  11-16 

Tetragraptus  fruticosus  rant.  {pars).  Ruedemann.  N.  Y.  State  Paleontol. 

An.  Rep’t  1902.  p.566 

Description .  Primary  disk  and  nema  not  observed.  Sicula  long 
(2 . 6  mm),  conspicuous,  slender.  Four  branches  dependent,  strongly  divergent 
approximately  under  right  angles,  curved  outward,  widening  rapidly  from  a 
width  of  .5  mm  at  their  basis  to  one  of  2.6  mm  or  more.  Thecae,  in  the 
mature  portion  of  the  branches  numbering  9  to  10  in  10  mm,  relatively  broad, 
two  to  three  times  as  long  as  wide,  about  6  mm  long,  inclined  at  an  angle  of 
30°,  overlapping  for  one  half  to  two  thirds  of  their  length ;  straight,  their 
outer  walls  and  apertural  margins  straight,  the  latter  normal  on  the  axes  of 
the  thecae. 

Position  and  localities.  T .  clarkei  has  been  found  only  in  graptolite 
bed  3,  associated  with  Goniograptus  geometricus,  Gonio- 
graptus  t  h  u  r  e  a  u  i ,  Didymograptus  s  i  m  i  1  i  s  and  Didymo- 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


653 


Remarks.  This  species,  which  originally  was  considered  a  later  mutation 
of  T.  fruticosus,  has  evidently  been  derived  from  that  species,  but  by 
the  process  of  acceleration,  the  geniculation  and  the  widening  of  the  branches 
take  place  so  closely  to  their  bases  and  so  rapidly,  that  this  form  bears  a 
greatly  different  aspect  from  the  typical  T.  fruticosus.  As  it  also  differs 
in  the  arrangement  of  the  thecae  and  is  restricted  to  another  horizon,  it  has 
the  morphologic  and  stratigraphic  value  of  a  separate  species.  The  thecae 
are  more  closely  arranged  than  in  the  mature  branch  of  T.  fruticosus, 
but  at  the  same  time  they  do  not  develop  some  of  the  mature  features  of 
those  of  T .  fruticosus,  as  they  do  not  become  so  strongly  inclined,  do 
not  overlap  so  much  and  do  not  possess  the  conspicuous  apertural  mucros  of 
the  progenitor.  In  general  outline  they  are  clearly  a  fuller  development  of 
the  variety  which  I  have  designated  as  T  .  fruticosus  t  u  b  i  f  o  r  m  i  s . 
The  earliest  thecae  of  the  branches  agree  still  with  those  of  the  like  stage  in 
T .  fruticosus. 

The  characters  of  the  proximal  parts  of  the  rhabdosome,  specially  the 
origin  of  the  first  thecae,  have  not  been  seen  with  sufficient  distinctness  to 
warrant  their  description. 


Tetragraptus  pendens  Elies 

Plate  11,  figures  17-20 

Tetragraptus  pendens  Elies.  Quar.  Jour.  Geol.  Soc.  Loud.  1898.  54:491, 
fig-13 

Tetragraptus  pendens  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.566 

Tetragraptus  pendens  Elies  &  Wood.  Monogr.  Brit.  Grapt.  Pal.  Soc.  for  1902. 
p.61,  pi. 6,  fig.  2a,  h 

On  slabs  derived  from  the  Didymograptus  bifidus  zone  occur  frequently 
specimens  of  a  small  Tetragraptus  ivhich  have  been  identified  with  a  form 
described  by  Miss  Elies  from  the  Middle  Skiddaw  slates.  From  the  species 
cited  as  being  associated  with  it  (  P  h  y  1 1  o  g  r  a  p  t  u  s  cf.  typus, 
Didymograptus  g  i  b  b  e  r  u  1  u  s  )  in  the  English  Lake  region,  we  infer 
that  this  organism  occurs  here  in  beds  liomotaxial  to  the  English. 


654 


NEW  YORK  STATE  MUSEUM 


While  ill  general  form,  size  and  aspect  the  form  closely  agrees  with  the 
figures  given  of  T.  pendens,  there  appear  some  small  differences  in  the 
measurements  which  are  thought  to  be  too  insignificant  to  indicate  a  variety. 

The  rhabdosome  is  small  (14  mm  greatest  length  observed),  slender 
(5 . 5  mm  greatest  width  observed),  consisting  of  four  dependent  branches 

which  are  subparallel  or  approach  slightly  distally,  form¬ 
ing  long,  flat  crescents.  The  sicula  is  relatively  short 
(1 . 3  mm)  and  rapidly  widening.  The  thecae  open 
toward  the  inner  side  of  the  rhabdosome,  increase  only 
slightly  in  width,  and  the  branches  are  therefore  of 
nearly  uniform  width.  The  thecae  are  long,  slender 
tubes  (length  1 . 6-2  mm),  which  at  the  beginning  of  the 
branches  do  not  overlap  more  than  £  of  their  length, 
the  overlap  increasing  to  not  cpiite  ^  of  their  length. 
Eight  to  10  thecae  were  counted  within  the  space  of 
10  mm.  The  angle  of  inclination  of  the  thecae  increases 
to  20°  or  even  22°  when  the  branch  assumes  mature 
features.  The  outer  margins  of  the  thecae  are  slightly 
concave,  with  a  small  increase  of  the  curvature  near  the 
aperture.  The  apertures  are  straight  or  slightly  con- 
pendens  Eiies  Enlarge-  cave,  and  they  iorin  an  anme  ot  about  110°  with  the 

ment  ot  proximal  portion  '  J  ° 

of  rhabdosome  to  show  the  •  «  , -i  -i  l _ 

character  of  sicula  and  the-  aXIS  OI  tlie  DranCiieS. 
cae.  Deep  kill.  x4.5 

Position  and  localities.  In  the  zone  with  D  i  d  y  - 
mograptus  bifid  us  and  Phyllograptus  anna,  on  slabs  with 
Didymograptus  b  i  f  i  d  u  s  and  Goniograptus  geometric  us. 
In  Great  Britain  it  occurs  in  the  Middle  Skiddaw  slates  of  the  Lake  district, 
associated  with  Didymograptus  (gibber ulus)  caduceus  and 
Phyllograptus  cf.  typus. 

Remarks.  It  has  been  pointed  out  by  the  author  of  the  species  that  it 
is  related  to  T.  fruticosus,  but  readily  distinguished  from  the  latter 
more  common  type  by  its  much  more  slender  form,  the  more  uniform  width 
of  the  branches,  closer  arrangement  of  the  thecae  and  smaller  angle  of  inclina- 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


655 


tion.  In  regard  to  the  latter  feature  this  species  approaches  the  nepionic  part 
of  the  branches  and  thus  appears  as  a  more  primitive  form.  It  could  there¬ 
fore  be  taken  for  a  derivative  of  T .  fruticosus  in  a  state  of  arrested 

m 

development,  and  lacking  the  tendency  to  reclination.  The  dependent  posi¬ 
tion  of  the  branches  in  this  species  is  also  maintained  in  its  closest  genetic 
relative,  Didymograptus  (indent  us)  dentatus. 

Tetragraptus  serra  Brongniart  sp. 

Plate  11,  figures  8-10 

Fucoides  serra  Brongniart.  Hist.  Veget.  Foss.  1828.  1:71,  pl.6,  fig.7,  8 

Didyimograpsus  caduceus  Salter  (parti).  Quar.  Jour.  Geol.  Soc.  1853.  9:87, 

fig.  la 

Graptolithus  bryonoides  Hall.  Geol.  Sur.  Can.  Rep’t  for  1857.  1858.  p.126 

Tetragrapsus  (bryonoides)  Salter.  Quar.  Jour.  Geol.  Soc.  1863.  19:137, 

fig- 8 

Didymograpsus  caduceus  Salter.  Ibid,  p.136 

Graptolithus  bryonoides  Hall  {pars).  Canadian  Organic  Remains,  decade  2. 
1865.  p.84,  pl.4,  fig.l-S,  11 

Graptolithus  bryonoides  Billings.  Geol.  Sur.  Can.  Pal.  Foss.  1865.  1:366, 

375 

Tetragrapsus  bryonoides  Nicholson.  Quar.  Jour.  Geol.  Soc.  1868.  24:131 

Graptolites  (Hidymograpsus)  bryonoides  McCoy.  Geol.  Sur.  Victoria. 

Prodr.  Pal.  Victoria,  decade  1.  1874.  p.15,  pi  2,  fig.2,  3,  5 

Tetragraptus  quadri  brae  hiatus  Etheridge  jr.  Ann.  and  Mag.  Nat.  Hist. 
ser.4.  1874.  14:3,  pl.3,  fig.5-8 

Tetragraptus  bryonoides  Etheridge  jr.  {pars)  Ibid,  p  2,  pl.3,  fig.  1 
Tetragraptus  serra  Hopkinson  &  Lapworth.  Ibid.  1875.  31:650,  pi. 33,  fig.10 
Tetragraptus  bryonoides  Linnarsson.  Sver.  Geol.  Und.  1879.  Afb.  och  upps. 
•  ser.C,  no.31,  p.5 

Tetragraptus  bryonoides  Brogger.  Die  sil.  Etagen  2  and  3.  1882.  p  38 
Tetragraptus  bryonoides  Tullberg.  Skanes  Grapt.  in  Sver.  Geol.  Und.  1882. 
Afh.  och  upps.  ser.C,  no.50,  p.22 

Tetragraptus  serra  Tdrnquist.  Sver.  Geol.  Und.  1883.  Afh.  och  upps.  ser.C, 
no.57,  p.16 

Tetragraptus  serra  Herrmann.  Geol.  Mag  ser.3.  18S6.  3:19 

Tetragraptus  serra  Ami.  Geol.  Sur.  Can.  Rep’t,  ser.2.  1889.  v.3,  pt2,  p,116k 


656 


NEW  YORK  STATE  MUSEUM 


Tetragraptus  s  e  r  r  a  Barrois.  Ann.  de  la  Soc.  Geol.  du  Nord.  1892.  20:94 

Tetragraptus  serra  Gurley.  Jour.  Geol.  1896.  4:295 

Tetragraptus  bryonoides  Romer  &  Frecb.  Lethaea  palaeozoica.  1897.  1:601 
Tetragraptus  serra  Elies.  Quar.  J our.  Geol.  Soc.  1898.  54:490 
Tetragraptus  serra  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.554,  556,  566 

Tetragraptus  serra  Elies,  Wood  &  Lapwortli.  Monogr.  Brit.  Grapt.  ptl.  Pal. 
Soc.  1902.  p.65,  pi. 6,  fig.4a-f 


Fitr.  r>6  Tetragraptus  serra 
Brongniart  sp.  Young  rhabdosome. 
Obverse  view.  Deep  kill.  x4.5 


Description.  Primary  disk  and  nema  not  observed.  Sicnla  relatively 
short  (2  mm)  and  slender.  First  theca  originating  within  apical  third  of 
sicnla.  Branch  of  first  order  (first  two  thecae)  short,  about  2.7  mm  long; 
four  branches  of  the  second  order  approximately  straight,  attaining  a  length 

of  80  to  50  mm,  rapidly  -widening  from  .  7  mm  to 
the  threefold  and  fourfold  -width.  Thecae  8  to  9 
in  10  mm,  narrow  (three  to  four  times  as  long  as 
wide),  slightly  curved,  much  inclined  (40°  to  45°), 
overlapping  for  two  thirds  to  three  fourths  of 
their  length.  Outer  thecal  walls  concave,  aper- 
tural  margin  concave,  normal  on  axis  of  thecae. 
Position  and  localities.  Brongniart’s  orig¬ 
inal  of  the  species  came  from  Point  Levis;  and  Hall  based  his  description 
on  material  from  Quebec  shales  of  Point  Levis,  Gros  Maule  and  River  St 
Anne.  The  form  is  evidently  very  common  in  the  Levis  region;  for  Ami 
cites  it  from  a  whole  series  of  localities  in  that  neighborhood.  Gurley  lists 
T.  serra  as  occurring  in  all  three  Quebec  zones,  the  Main  Point  Levis 
zone,  the  Phyllograptus  anna  zone  and  the  Upper  Levis  zone.  Besides,  he 
found  it  also  in  the  suite  submitted  to  him  from  Arkansas.  Billings  noted 
the  specie's  among  the  graptolites  from  Cowhead,  Newfoundland  (division  P). 

In  the  preliminary  paper  on  the  Deep  kill  section,  I  reported  this  form  as 
being  rare  in  graptolite  bed  1,  common  in  graptolite  bed  2,  as  being  found 
in  a  small  mutation  in  graptolite  bed  8,  and  as  passing  through  the 
Didymograptus  bifidus  zone  (graptolite.  beds  3  to  5).  It  occurs  also  associ¬ 
ated  with  D  i  c  t  y  one  m  a  m  u  r  r  a  y  i ,  a  species  of  Clonograptus  and 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


657 


T .  quadribrachiatus  in  a  sandy  slate  between  Defreestville  and  W est 
Sandlake,  Rensselaer  co.  N.  Y.  [T.  N.  Dale,  coll.J  In  the  second  instalment  of 
the  Monograph  of  the  British  Graptolites,  which  has  just  appeared,  the  species 
as  defined  by  Hall  has  been  split  and  a  part  separated  as  T,  amii.  This  new 
species  is  common  in  graptolite  bed  2,  and  its  separation  will  make  T .  serra 
a  less  frequent  form  in  that  bed.  Also  the  form,  listed  as  a  smaller  mutation 
of  T .  serra  from  the  zone  of  Didymograptus  b  i  f  i  d  u  s ,  must  be 
separated  as  a  new  species.  T  .  serra,  thus  limited,  is  in  the  Deep  kill  sec¬ 
tion  restricted  to  the  first  two  beds  (zone  with  Tetragraptus.) 

In  Great  Britain  the  form  has  long  been  known  by  Salter’s,  Nicholson’s, 
Lapworth’s  and  Hopkinson’s  investigations.  It  occurs  there  in  the  upper 
beds  of  the  Middle  Skiddaw  slates, 
associated  with  like  forms  as  in  America; 
in  the  Lake  district,  in  south  Scotland 
and  in  south  Wales. 

In  Scandinavia  it  is  known  to  occur 
in  Tetragraptus  shales  in  the  region  of 
Christiana  [Brogger],  in  Skane  [Tullberg],  West  Gothland  and  Dalecarlia. 
Barrois  records  it  among  the  fossils  from  the  graptolite  schists  of  Boutoury 
near  Cabrieres  in  southern  France,  and  it  was  early  found  in  Victoria, 
Australia. 

Remarks.  This  species  exhibits  also  the  strengthening  of  the  branches 
by  a  thickening  of  the  dorsal  wall  of  the  coenosarcal  canal,  mentioned  in  the 
descriptions  of  T.  quadribrachiatus  and  T.  amii.  As  it  agrees  in 
nearly  all  essential  features,  except  the  direction  of  the  branches,  with  the 
latter,  there  is  little  doubt  that  it  is  derived  from  that  species  and  marks  a 
further  stage  in  the  process  of  the  gradual  elevation  of  the  originally  depen¬ 
dent  branches  into  a  reclined  position  by  way  of  a  horizontal  disposition. 

The  young  of  this  species,  which  are  quite  common  in  graptolite  bed  2, 
possess  a  characteristic  aspect,  by  having  been  compressed  in  such  a  fashion 
that  two  branches  appear  to  have  a  dependent  and  two  a  reclined  position 
[pl.ll,  fig.8]. 


Fig.  57  Tetragraptus  sen  a  Brongniart  up. 
Fragment  of  branch.  Shows  the  form  arid  inclina¬ 
tion  of  the  thecae;  and  the  thick  dorsal  wall  of  the 
coenosarcal  canal.  Deep  kill,  x4.8 


658 


NEW  YORK  STATE  MUSEUM 


Tetragraptus  similis  Hall  (sp.) 

Plate  12,  figures  2-10 

Phyllograptus  si  mil  is  Hall.  Geol.  Sur.  Can.  Rep’t  for  1857.  1858.  p.140 

Didymograpsus  caduceus  Salter?  Quar.  Jour.  Geol.  Soc.  1863.  19:137, 

%.13b(?) 

Graptolithus  bigsbyi  Hall.  Canadian  Organic  Remains,  decade  2.  1865. 

p.86,  pi.  16,  tig.22-30 

Didymograptus  caduceus  Nicholson.  Quar.  Jour.  Geol.  Soc.  1868.  24:133 

Tetragraptus  bryonoides  Etheridge  jr.  Ann.  and  Mag.  Nat.  Hist,  ser.4. 
1874.  14:2,  pi. 3,  fig.l,  2;  non  fig.3,  4 

Tetragraptus  bigsbyi  Linnarsson.  Sver.  Geol.  Und.  1879.  Afh.  och  upps. 
ser.C,  no.31,  p.5 

Tetragraptus  bigsbyi  Tullberg.  Ibid.  18S2  ser.C,  no. 50,  p.22 
Tetragraptus  caduceus  Brogger.  Die  sil.  Et.igen  2  and  3.  1882.  p.38 

Tetragraptus  bigsbyi  Ami.  Geol.  Sur.  Can.  Rep’t,  ser.2.  1889.  v.3,  pt2, 

p,116k 

Tetragraptus  caduceus  Perner.  Etudes  sur  les  Grapt.  de  Boheine,  pt2.  1894, 
p.20,  pi. 6,  tig.9-12 

Tetragraptus  bigsbyi  Holm.  Sver.  Geol.  Und.  1895.  Afh.  och  upps. 

ser.C,  no.150,  p.24,  pl.l,  fig.9-16;  pi. 2,  fig.1-3;  pi  3,  tig.13-16 
Tetragraptus  bigsbyi  Holm.  Geol.  Mag.  Dec.  4, 1895.  2:484,  pi. 13,  fig.9-16  ; 

pl-14,  fig  13-16  ;  p.485,  fig.1-3 

Tetragraptus  bigsbyi  Gurley.  Jour.  Geol.  1896.  4:294 

Tetragraptus  bigsbyi  Roemer  &  Freeh.  Lethaea  palaeozoica.  1897.  1:600, 

601,  fig.166 

Tetragraptus  bigsbyi  Elies.  Quar.  Jour.  Geol.  Soc.  1898.  54:488 

Tetragraptus  bigsbyi  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.556,  566 

Tetragraptus  bigsbyi  Elies  &  Wood.  Monogr.  Brit.  Grapt.  ptl.  Pal.  Soc.  for 
1902.  1902.  p.68,  pi. 6,  fig.6a-e 

Non  Didymograpsus  caduceus  Salter.  Quar.  Jour.  Geol.  Soc.  1853.  9:87, 
fig.  la 

Non  Graptolites  (Didymograpsus)  caduceus  McCoy.  Prodr.  Pal.  Vic¬ 
toria,  decade  1.  1875.  p.  1 6,  pl.2,  fig.2,  3,  5 

Non  Tetragraptus  bigsbyi  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t. 
1902.  p.590,  fig.  18 


GRAPTOLITES  OP  NEW  YORK.  PART  1 


659 


Description.  Small  subcircular  primary  disk  and  very  thin  filiform  nema. 
Rhabdosome  of  small  size  (usual  length  about  12  mm);  forming  a  broad 
oval  in  younger,  a  more  elongate  truncate  oval  in  older  specimens ;  consisting 
of  four  relatively  wide  branches  (1 .6  mm  at  their  origin,  rapidly  attaining  a 
width  of  2.5  mm  and  diminishing  again  toward  the  extremity),  which  in 
most  specimens  are  straight  or  slightly  concavely  curved  on  the  dorsal  side 
and  present  a  stronger  convex  outline  on  the  frontal  side. 

Sicula  about  2 . 1  mm  long,  stout.  Branches  of  the  first  order  monothecal, 
each  1 . 1  mm  long.  Those  of  the  second  order  short  (rarely  exceeding  13  mm 
in  length),  in  typical  specimens  flexed,  curving  upward  and  inward.  Thecae 


Fig.  58  Tetragraptus  si  mil  is  Hall  sp.  Two  specimens.  In  which 
only  the  branches  of  one  side  are  retained ;  in  a  the  branches  are  seen  from 
the  outside ;  in  b  from  the  inside  of  the  rhabdosome.  Deep  kill.  x5.25 


numbering  10  to  14  in  the  space  of  10  mm,  gradually  ascending  (initial  angle 
about  50°),  but  curving  outward  in  their  distal  parts  (angle  60°  to  70°), 
widening  toward  the  aperture,  four  times  as  long  as  wide;  in  contact  four 
fifths  of  their  length.  Apertural  and  external  margins  slightly  concave,  both 
forming  a  characteristic  recurving,  mucronate  apertural  denticle. 

Position  and  localities.  Occurring  in  great  profusion  in  the  Tetragraptus 
bed  of  the  Deep  kill,  specially  graptolite  bed  2,  still  met  in  scarce  and  depau¬ 
perated  specimens  in  graptolite  bed  3,  which  represents  the  lower  part  of  the 
zone  with  Didymograptus  bifidus. 

This  species,  which  in  mature  representatives,  is  very  readily  recognized 
by  the  curved,  relatively  broad  branches  and  the  curved  apertural  denticles, 
is  evidently  a  form  of  vast  distribution.  It  was  originally  described  by  Hall 
as  occurring  in  great  multitudes  in  the  Quebec  shales  at  Point  Levis,  where 


(!(>0 


NEW  YORK  STATE  MUSEUM 


according  to  Gurley  it  is  found  in  the  Main  Point  Levis  or  Tetragraptus  zone. 
Ami  cites  it  also  from  two  localities  near  Levis  together  with  Didymo- 
g  r  a  p  t  u  s  b  i  f  i  d  u  s .  In  Britain  it  is  known  from  many  localities  in  north¬ 
ern  England  and  south  Scotland,  where  it  occurs  in  the  Lower  and  Middle 
Skiddaw  slates.  It  is  further  recorded  by  Brogger  from  the  lower  part  of 
the  Phyllograptus  shale  at  Krekling,  Christiania,  Norway;  from  the  Tetra¬ 
graptus  zone  of  Scania  by  Tullberg;  and  the  gray  Orthoceras  limestone  of 

Oeland  furnished  to  Holm  the  material  of  this 
species,  on  which  he  based  his  investigation  of  the 
structure  of  Tetragraptus ;  Perner  describes  T. 
bigsbyi  from  band  Ddl/5  of  the  Bohemian 
Lower  Siluric,  the  occurrence  of  this  species  in 
Bohemia  having  before  been  reported  by  Tornquist; 
in  Australia,  finally,  it  has  been  recognized  by  the 
younger  Etheridge  in  the  auriferous  graptolite  shale  of  Victoria. 

Remarks.  Specimens  in  which  the  distal  ends  of  the  branches  had  been 
in  contact,  either  by  compression  or  natural  position,  had  been  described  by 
Hall  as  Phyllogr  a  p  t  u  s  s  i  m  i  1  i  s ,  a  name  which  was  withdrawn  later 
on  by  its  author  on  account  of  the  supposed 
precedence  of  his  species  Graptolithus 
similis.  Since  the  latter  belongs  to  another 
genus  (Didymograptus),  the  term  T .  similis 
would,  according  to  the  present  rules  of  priority, 

,  ,  .  i  •  jii  i  i  j  n  60  Tetragraptus  similis 

have  to  stand  against  the  later  and  generally  uaii  «p.  Proximal  portion  0f  rhawo- 

°  J  some.  Obverse  view.  Deep  kill.  x4.5 

adopted  name,  T .  bigsbyi. 

Our  list  of  synonyms  demonstrates  that  several  authors  have  referred 
this  species  to  Salter’s  D i d y mograptus  caduceus.  We  shall  show 
under  that  heading  [p.696]  that  Salter  figured  under  this  name  a  specimen  of 
Didymograptus  and  a  fragment  of  T .  similis  Hall ;  and  that  according  to 
the  rules  of  priority  his  name  will  have  to  be  applied  to  the  first  figured  form, 
i.  e.  to  Didymograptus  caduceus.  In  no  case  can  Salter’s  name 
be  employed  to  designate  this  tetragraptid. 


Fig. 59  Tetragraptus  similis 
Hall  ftp.  Young  compressed  rliab- 
dosome  seen  from  the  under  side. 
Shows  the  apertures  of  the  sicula 
aud  first  two  thecae.  Deep  kill.  x6 


GRAPTOLITES  OF  NEW  YORK.  TART  1 


GG1 


The  different  direction  of  compression  alters  the  aspect  of  this  species 
very  considerably.  The  distinctive  characters  cited  before  suffice  however 
fully  for  its  recognition  in  all  cases.  We  have  figured  some  of  the  more  strik¬ 
ing  aspects.  It  appears  that,  on  the  whole,  the  branches  of  the  Deep  kill 
specimens  are  somewhat  narrower,  or  at  least  do  not  reach  the  maximal  width 
cited  by  Hall  and  Elies,  while  in  all  other  respects,  specially  the  length  which 
they  attain,  they  do  not  differ  from  the  descriptions  given  by  these  authors. 

In  a  paper  on  the  growth  and  development  of  Gr  o  n  iograptus 
thureaui,  the  writer  figured  two  extremely  minute,  apparently  young 
specimens  of  a  Tetragraptus,  which  he  then  thought 
referable  to  this  species.  Subsequent  investigation  has 
shown,  that  notwithstanding  the  resemblance  between 
these  and  the  mature  specimens  of  T.  si  mil  is,  the 
young  of  the  latter  form  are  quite  different,  their  sic- 
ulae  being  larger  and  stouter,  and  not  projecting  below 
the  first  few  thecae.  As  these  minute  rhabdosomes  could 
not  be  referred  to  any  other  species  of  Tetragraptus,  they 
have  been  described  as  a  new  type  (  T .  p  y  gmaeus). 

Holm  succeeded  in  isolating  specimens  of  T.  similis  (bigsbyi) 
and  thus  elucidating  the  structure  of  the  proximal  parts.  He  also  gives 
figures  of  a  very  young  specimen,  showing  the  “  Didymograptus  stage,”  i.  e. 
the  sicula,  the  left  and  right  thecae  and  the  connecting  canal.  Some  of  his 
instructive  figures  have  been  copied  in  the  discussion  of  the  genus. 

The  surfaces  of  graptolite  bed  2  at  the  Deep  kill  are  covered  with 
growth  stages  of  this  species.  These  verify  Holm’s  observations,  so  far  as 
their  flattened  condition  permits  the  study  of  their  original  structure.  We 
figure  several  of  these  stages  which  exhibit  important  features  [pi. 12,  fig.8-10]. 
Specially  remarkable  among  them  is  the  very  long,  extremely  thin  filamentary 
nema,  which  in  one  specimen  [fig.10]  is  seen  to  end  in  a  relatively  large, 
thinly  chitinous  disk  with  a  somewhat  thickened  central  part. 

Very  frequently  the  two  branches  of  one  side  alone  are  preserved 
[fig.58],  ■whereby  the  fossil  receives  the  appearance  of  a  Didymograptus,  of 


Fig;.  61  Tetragraptus 
similis  Hall  sp.  Frag¬ 
ment  of  branch  enlarged 
to  show  the  characteristic 
aspect  of  the  thecae  in  the 
compressed  condition.  Deep 
kill.  x4.5 


662 


NEW  YORK  STATE  MUSEUM 


the  group  of  D.  caduceus.  The  two  forms  have  no  doubt  been  fre¬ 
quently  confused  for  this  reason.  The  character  of  the  thecae  and  the  differ¬ 
ent  width  of  the  proximal  parts  of  the  rhabdosomes  furnish  however  a  ready 
means  of  distinction.  Young  colonies  also  frequently  become  so  obliquely 
compressed  that  both  pairs  of  branches  fall  into  one  plane,  each  pair  forming 
a  horseshoelike  curve,  and  the  primary  thecae  and  sicula  together  become 
visible  [pl.l  2,  fig.4].  Older  specimens  are  nearly  always  laterally  compressed. 

Tetragraptus  woodi  sp.  nov. 

Plate  12,  figures  1,  15, 16 

Tetragraptus  bigsbyi  Ruedemann  {pars).  N.  Y.  State  Paleontol.  An.  Rep’t. 

1902.  p.556 

Description.  Primary  disk  unknown ;  nema  very  thin,  filiform.  Rhabdo- 
some  of  small  size  (about  19  mm  in  length).  Sicula  conspicuous,  about 
1.7mm  long ;  first  theca  originating  near  the  apex  of  the  sicula,  apparently 
of  like  character  and  direction  of  growth  as  in  T.  similis;  first  and  second 
thecae  forming  two  branches  of  the  first  order,  which  have  a  horizontal  direc¬ 
tion.  Branches  of  the  second  order  17  to  19  mm  long  in  their  mature  state, 
approximately  straight  or  curving  outward,  directed  obliquely  upward, 
diverging  under  angles  of  30°  to  50° ;  mostly  under  40°  in  the  compressed 
state ;  widest  at  the  base  (2 . 2  mm),  and  diminishing  regularly  toward  the 
distal  end  to  1.4  mm.  Thecae  about  16  in  10  mm  in  the  proximal  portion, 
and  quite  constantly  12  in  the  same  space  in  the  distal  portion  ;  curved, 
strongly  inclined  (about  50°) ;  widening  toward  the  aperture,  twice  as  wide 
at  aperture  as  at  base ;  short  (1 . 4  mm  near  base)  ;  twice  as  long  as  wide  (in 
distal  parts  of  branches)  ;  in  contact  one  half  to  three  fifths  of  their  length ; 
apertural  margin  approximately  straight  if  fully  exposed,  but  as  a  rule 
appearing  curved  and  slightly  oblique  to  the  axis  of  the  thecae  in  distal 
thecae,  producing  with  the  concave  outer  margin  a  recurved  apertural 
denticle. 

Position  and  locality.  Found  as  the  predominant  form  in  a  single  sur¬ 
face  of  graptolite  bed  2  at  the  Deep  kill,  associated  with  Goniograptus 


GRAPTOLITES  OF  NEW  YORK,  TART  1 


663 


perflexilis,  Tetragraptus  fruticosus,  Didymograptus 
n  i  ti  d  u  s . 

Remarks.  This  form  agrees  in  the  character  of  its  thecae  fully  with 
T.  (bigsbyi)  similis  and  has  therefore  been  first  considered  by  the 
writer  as  a  variety  of  that  species.  The  constancy  and  importance  of  its 
differential  characters,  and  the  absence  of  transitional  forms  to  T .  similis 
are,  however,  sufficient  evidence  of  the  fixation  of  this  type  and  of  its 
specific  value.  It  differs  from  T.  similis  principally  by  the  greater 
length,  straight  direction,  obliquely  outward  growth  and  regular  tapering  of 
the  branches.  In  its  central  portion  and  the  basal  parts  of  the  secondary 
branches  it  does  not  differ  materially  from  T.  similis.  Pt,  therefore,  repre 
sents  undoubtedly  a  further  development  of  that  species  in  a  direction,  how¬ 
ever,  different  from  that  leading  to  Phyllograptus. 

Tetragraptus  taraxacum  Ruedemann 

Plate  12,  figures  17-26 

Tetragraptus  taraxacum  nom.  nud.  Ruedemann.  N.  Y.  State  Paleontol.  An. 

Rep’t.  1902.  p.5S9,  fig.16 

A  small  but  very  characteristic  form,  which  is  easily  recognized  among 
the  multitude  of  species  intermixed  on  the  slabs  of  the  Tetragraptus  beds 
(graptolite  bed  no.  2). 

Description.  The  sicula  is  middle  sized  and  slender  (1.3  to  1.7  mm). 
The  two  primary  thecae,  the  first  of  which  buds  in  about  the  middle  of  the 
sicula,  are  very  long,  cylindric  (1  to  1.4  mm)  and  diverge  at  approximately 
right  angles  from  the  sicula.  The  four  ultimate  branches  which  spring  from 
the  same  are  gently  curved  upward  to  such  an  extent  that  they  rise  only  a 
little  above  the  apical  end  of  the  sicula.  The  angle  of  divergence  between 
each  pair  of  branches  apparently  amounted  to  as  much  as  180°.  Their  aver¬ 
age  length  is  6  mm;  greatest  width  1.4  mm;  greatest  length  observed  9.7  mm. 

The  first  theca  of  each  branch  is  still  long  and  tubular  and  provided  with 
a  straight  apertural  margin  as  the  primary  thecae ;  the  following  thecae 
assume  rapidly  a  very  different  aspect  by  widening  strongly  toward  the 


GW 


NEW  YORK  STATE  MUSEUM 


aperture  and  increasing  in  overlap.  Their  outer  margins  are  strongly  con¬ 
cave  and  the  apertural  margins  protracted,  convex  and  recurving,  giving  the 
distal  thecae,  in  a  lateral  view,  a  bluntly  cuspidate  aspect.  The  mature 
thecae  are  three  times  as  wide  at  the  aperture  as  at  the  initial  point ;  the 
overlap  increases  within  each  branch  from  one  fourth  to  a  little  more  than 
one  half.  There  are  12  thecae  in  10  mm,  the  outer  margins  of  which  at  the 
beginning  of  the  branch  form  an  angle  of  4°  and  at  the  distal  parts  an  angle 
of  40°  to  60°  with  the  axis  of  the  branch.  The  angle  between  the  apertural 
margin  and  the  axis  of  the  branch  is  about  60°. 

Position  and  localities .  The  majority  of  the  specimens  have  been 
obtained  in  graptolite  bed  2,  of  the  Deep  kill  section,  belonging  to  the 
Tetragraptus  zone ;  a  few  were  also  observed  in  the  beds  with  Diplo- 
g  r  a  p  t  u  s  dentatus  at  M't  Moreno,  near  Hudson  N.  Y.  The  species 
appears  hence  to  range  through  several  zones. 

Remarks.  This  type  is  remarkable  for  the  long  slender  shape  of  the 
earlier  thecae  of  the  rhabdosome  and  the  abrupt  change  to  more  curved  and 
more  closely  arranged  thecae,  which  are  provided  with  protracted  apertures 
and  form  a  greater  angle  of  divergence  with  the  axis  of  the  branch.  The 
latter  change  is  consequent  on  the  closer  arrangement  and  greater  overlap  of 
the  thecae.  This  abrupt  change  in  the  shape  and  arrangement  of  the  thecae 
appears  as  an  interesting  illustration  of  acceleration  of  development  in  the 
ontogeny  of  the  branches  [1902,  p.589],  the  transitional  stages  between  the 
earlier  and  mature  thecae  being  here  omitted.  This  feature,  the  small  size  of 
the  rhabdosomes  and  the  gentle  curvature  of  the  branches  will  easily  dis- 
tinguish  it  from  the  other  congeners. 

Tetragraptus  pygmaeus  sp.  nov. 

Plate  12,  figures  11-14 

Tetragraptus  bigs  by  i  Ruedemann  {pars).  N.  Y.  State  Paleontol.  An.  Rep’t. 

1902.  p.590,  tig.  18 

In  a  former  paper  [1 902,  p.590]  the  author  of  the  present  memoir  has 
referred  minute  tetragraptids,  occurring  in  considerable  number  in  graptolite 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


665 


bed  2  of  the  Deep  kill  section,  on  account  of  their  general  similarity  in  early 
growth  stages,  to  T.bigsbyi  Hall.  Subsequent,  more  detailed  investiga¬ 
tions,  and  specially  a  close  comparison  of  these  supposed  growth  stages  with 
the  proximal  ends  of  T.bigsbyi,  described  by  Holm,  have  demonstrated 
the  error  of  this  reference  and  the  fact  that  these  pygmies  among  the  grapto- 
lites  represent  a  species  of  their  own,  which  differs  in  important  characters 
from  the  other  congeners. 

Description.  Primary  disk  cliitinous,  subcircular,  of  small  proportions 
[fig.13,  about  1mm  in  diameter];  nema  of  varying  length  [fig.  11];  sicula 
relatively  long  (1.4  mm)  and  slender  (width  at  aperture  but  .3  mm),  with  long 
apertural  spines;  projecting  beyond  the  branches  of  the  first  order  by  one 
fourth  or  more  of  its  length ;  branches  of  first  order  monotliecal,  diverg¬ 
ing  perpendicularly  from  the  sicula,  about  .6mm  long;  each  producing  by 
dichotomy  two  branches  of  the  second  order,  the  latter  reclined ;  subparallel 
to  the  sicula,  very  small  (maximal  length  observed  but  2.7  mm).  Thecae 
very  minute,  numbering  18  in  10  mm,  short,  twice  as  wide  as  long;  gradually 
ascending  (initial  angle  about  30°) ;  strongly  curving  outward  in  the  distal 
parts  (80°  to  90°),  at  the  aperture  twice  as  wide  as  at  the  base.  Outer  margin 
strongly  concave ;  apertural  margin  slightly  concave,  provided  with  acute 
apertural  denticles,  which  on  the  two  primary  thecae  appear  to  develop  into 
spines. 

Position  and  localities.  Quite  common  in  the  graptolite  bed  2  (belong¬ 
ing  to  the  Tetragraptus  zone) ;  also  rarely  observed  in  graptolite  bed  3,  on 
slabs  with  D  i  d  y  in  o  g  r  a  p  t  u  s  b  i  f  i  d  u  s  and  Goniograptus  geome- 
t  r  i  c  u  s  and  in  the  beds  with  Diplograptus  dentatus  at  Mt  Moreno, 
near  Hudson  N.  Y. 

Remarks.  This  species  is  apparently  related  to  T  .  (b  i  g  s  b  y  i)  s  i  m  i  1  i  s, 
with  which  it  agrees  in  the  general  form  of  rhabdosome  and  thecae.  It  can 
be  distinguished  from  growth  stages  of  that  larger  type  by  the  smallness  of 
its  thecae,  slenderness  and  protrusion  of  the  sicula  beyond  the  primary 
branches  and  the  acute  denticles  of  the  thecae. 


GGG 


NEW  YORK  STATE  MUSEUM 


Tetragraptus  (Etagraptus)  lentus  sp.  nov. 

Plate  9,  figures  7-10 

Description.  Sicilia  large  (2.1mm)  and  slender.  Primary  theca  generally 
budding  from  the  first  third  of  the  sicula,  this  and  the  next  forming  right 
angles  with  it;  narrow,  tubular  and  long  (l.G).  Secondary  branches  at 
first  forming  obtuse  angles,  generally  about  1 20°,  with  the  primary  branches, 
but  later  on  assuming  positions  perpendicular  to  them.  Branches  narrow 
and  flexuous,  maximal  width  .37  mm,  total  length  not  known.  Thecae 
extremely  long  (attaining  a  length  of  2.4  mm),  tubular  and  slightly  curved ; 
seven  times  as  long  as  wide,  little  widening  toward  the  aperture ;  over¬ 
lapping  not  more  than  one  fourth  of  their  length,  numbering  6  in  10  mm. 
Outer  wall  subparallel  to  the  axis  of  the  branch,  forming  an  angle  not 
surpassing  5°  with  the  latter.  Apertural  margin  straight  and  perpendicular 
to  the  axis  of  the  branch. 

Position  and  localities.  Grraptolite  bed  3  at  the  Deep  kill.  On  slab  with 
Didymograptus  b  i  f  i  d  u  s  and  Groniograptus  geometricus. 

Demarhs.  There  is  no  similar  form  known  to  the  writer  which  would 
invite  comparison.  Coenograptus  gracilis,  while  readily  dis¬ 
tinguished  by  the  arrangement  of  the  branches,  has  very  similar  thecae  and 
branches.  The  direction  of  the  secondary  branches  is  in  this  species  the 
same  as  in  Tetragraptus  a  p  p  r  o  x  i  m  a  t  u  s  Nicholson,  which,  however, 
is  entirely  different  in  the  character  of  sicula  and  thecae. 

DIDYMOGRAPTUS  McCoy 

The  genus  Didymograptus  Was  proposed  by  McCoy  [1851,  p.9j  for 
uniserial  forms,  which  are  bifid  from  the  base.  Later  Hopkinson  separated 
the  forms  with  solid  axes  in  the  branches  under  the  generic  term  Dicello- 
graptus. 

We  have  in  the  introduction  attempted  to  trace  the  genetic  relationship 
of  the  species  of  Didymograptus,  described  in  this  publication,  to  forms 
with  a  greater  number  of  branches ;  and  there  discussed  the  fact  that  the 
various  Didymograptidae  represent  the  biramous  development  of  different 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


667 


series  of  originally  raultiraraous  forms.  The  genus  is  hence  like  Tetragraptus 
polyphyletic  and  expresses  a  stage  reached  nearly  simultaneously  along  many 
lines  of  evolution.  It,  accordingly,  falls  naturally  into  groups  which  probably 
unite  species  of  actual  genetic  relationship.  These  groups  have,  through 
the  larger  and  more  varied  association  of  British  Didymograptidae,  recently 
been  determined  by  the  monographers  of  the  fauna  of  that  country.  They 
have,  again,  by  common  characteristics  of  general  habit,  been  arranged  into 
series.  These  are  based  largely  on  the  divergence  of  the  branches,  which 
compasses  the  entire  circumference  of  a  circle  [see  diagram,  p.485],  probably 
in  consequence  of  the  endeavors  of  the  branches  to  assume  progressively  a 
more  and  more  erect  position  from  the  point  of  suspension  (the  sicula). 
We  have  adopted  here  for  the  arrangement  of  our  species  of  Didymograptus 
the  grouping  proposed  by  Elies  and  Wood. 


Group  1  Type  :  D.  extensus 
D.  extensus 
D.  n i t  i  d  u  s 
II).  p  a  t  u  1  u  s 
D.  s i m  i  lis 
.D.  gracilis 
Group  2  Not  represented 


^Horizontal  series 


Group  3  Type:  D.  affinis 
'  D.  e  1 1  e  s  i 
D.  acutidens 
D.  cuspidatus 
-  D.  nicliolsoni  var.  planus 
D.  filiformis 
D.  tornquisti 
D.  spinosus 


*  Declined  series 


Group  4  Not  represented 

Group  5  Type :  D.  murchisoni 


a  Subgroup  of  D.  b  i  f  i  d  u  s 
D.  bif idus 

b  Subgroup  of  D.  indentus 
D.  nanus 


►  Dependent  series 


668 


NEW  YORK  STATE  MUSEUM 


Group  6  Not  represented 

Group  7  Type:  D.  caduceus 
D.  caduceus 
D.  caduceus  var.  nanus 
D.  forcipiformis 
D.  incertus 


*  Reclined  series 


Didymograptus  extensus  Hall  sp. 

Plate  13,  figures  17,  18 ;  plate  It,  figures  1-4 

Graptolitlius  extensus  Hall.  -  Geol.  Sur.  Can.  Rep’t.  1858.  p.132 

Graptolitlius  extensus  Hall.  Canadian  Organic  Remains,  decade  2.  1865. 

p.80,  pi. 2,  fig.11-16 

Graptolithus  c  o  n  s  t  r  i  c  t  u  s  Hall  (  p  a  r  s) .  Ibid,  p.76,  pl.l,  tig  23-27 
Didymograptus  e  x  tens  us  Nicholson.  Ann.  and  Mag.  Nat.  Hist.  ser.  4.  1870. 

4:341,  pi. 7,  fig.2,  2a 

Didymograptus  extensus  Hopkinson  <fc  Lapworth.  Quar.  Jour.  Geol.  Soc. 
1875.  31:642,  pl.33,  fig.la-ld 

IGraptolites  (Didymograptus)  extensus  McCoy.  Geol.  Sur.  Victoria. 

Prodr.  Pal.  Victoria,  decade  2.  1875.  p.29,  pi  20,  tig.l,  la 

Cf.  Didymograptus  constrictus  Linnarsson.  1879 
Didymograptus  e  x  t  e  n  s  u  s  Brogger.  Die  sil.  Etagen  2  and  3.  1882.  p.40 

Cf.  Didymograptus  constrictus  Brogger.  Ibid.  1882 
Didymograptus  extensus  Herrmann.  Geol.  Mag.  Dec.  3,  1886.  3:14 

Cf.  Didymograptus  constrictus  Herrmann.  Ibid 

Didymograptus  e  x  t  en  su  s  Lapwortli.  Roy.  Soc.  Can.  Proc.  and  Trans.  1887. 
4:168,  184 

Didymograptus  extensus  Ami.  Geol.  Sur.  Can.  Rep’t,  ser.2.  1889.  v.3, 

pt2,  p.H6k 

Cf .  Didymograptus  constrictus  Ami.  Ibid 

Didymograptus  extensus  Roemer-Frech.  Lethaea  palaeozoica.  1897.  1:591 

Didymograptus  e  x  te  n  s  u  s  Elies.  Quar.  Jour.  Geol.  Soc.  1898.  54:504 

Didymograptus  extensus  Tornquist.  Lunds  Univ.  Arsskrift  1901.  Bd  37, 
Af.2,  Nr  5,  p.14,  pl.l,  fig.25-30 

Cf.  Didymograptus  c  o  n  st  r  i  c  t  u  s  Tornquist.  Ibid,  p.17,  pi. 2,  tig.13-17 
Didymograptus  extensus  Elies  &  Wood.  Monogr.  Brit.  Grapt.  ptl.  Pal. 
Soc.  vol.  for  1901.  p.8,  pl.l,  fig.la,  b 

Didymograptus  extensus  Ruede:ninn.  N.V.  State  Paleontol.  An.  Rep’t. 
1902.  p.556 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


660 


Fig.  62  Didymograptus  extensus  Hall  sp.  Proximal 
part  of  rhabdosome.  Reverse  view.  Deep  kill.  x5.25 


Description.  Primary  disk  subcircular,  relatively  large  (diameter  5  mm 
where  the  rhabdosome  has  a  length  of  6.5  mm),  nema  short,  filiform,  very 
thin.  Sicula  inconspicuous,  short  (1.3  mm)  and  relatively  broad.  Branches 
horizontal,  angle  of  divergence  180°;  attaining  great  length  (incomplete 
specimens  measure  upward  of  40  cm),  increasing  very  gradually  in  width 
from  .7  mm  to  2.4  mm;  slightly  flexuous.  Thecae  9  in  10  mm;  short  and 
broad  (proportion  of  length  to 
width,  2:1  in  the  proximal  por¬ 
tion  and  3:1  in  the  distal  portion), 
attaining  a  length  of  2.2  mm  in 
the  distal  part ;  in  contact  for  one 
half  of  their  length  in  the  proximal  and  two  thirds  in  the  distal  parts ; 
inclined  at  an  angle  of  35°  to  40°.  Outer  and  apertural  margins  straight,  the 
latter  normal  to  the  axis  of  the  theca  (inclined  at  130°  to  the  axis  of  branch). 

Position  and  localities.  At  the  Deep  kill  this  species  has  been  found 
only  in  graptolite  bed  2  (Upper  Tetragraptus  zone),  where  it,  in  association 
with  Tetragraptus  similis,  covers  one  layer  and  in  others  is  very 
common  and  associated  with  Dichograptus  octobrachiatus,  Tetra¬ 
graptus  fruticosus  and  Phyllograptus  ilicifolius.  Hall 

obtained  his  types  from  the  Quebec  group 
at  Point  Levis  (Tetragraptus  zone)  ;  Lap- 
worth  records  it  also  from  the  zone  with 
Phyllograptus  anna,  citing  as 
locality  “  3  miles  above  St  Anne  ” ;  and 
Ami  lists  D.  extensus  from  several  localities  in  the  neighborhood  of 
Levis.  In  Great  Britain  it  has  been  recognized  in  the  Middle  Skiddaw 
slates  of  the  Lake  district;  in  the  St  David’s  district  and  the  Lleyn 
peninsula  of  Wales  (Hick’s  Lower  Arenig) ;  in  Shropshire ;  and  in  the 
Ballantrae  district  in  Scotland.  Brogger  records  it  from  the  Phyllograptus 
shale  of  the  Christiania  region ;  Tornquist  found  it  in  the  zone  of 
Isograptus  gibber  ulus  (lowest  zone  of  his  Pliyllo-Tetragraptus 
beds)  of  Scania ;  and  Freeh  mentions  it  also  from  the  Hunneberg  in 


m.-* 


Fig.  63  Didymograptus  extensus  Hall 
sp.  Fragment  of  proximal  part  of  branch.  Deep 
kill.  x5.25 


670 


NEW  YORK  STATE  MUSEUM 


Westrogotkia.  It  is  not  reported  from  tke  Bohemian,  Belgian  and 
French  graptolite  beds.  McCoy  identified  a  graptolite,  which  he  found 
abundantly  in  Victoria,  with  this  species,  but  his  description  and  figures  indi¬ 
cate  a  somewhat  closer  arrangement  and  a  greater  inclination  of  the  thecae. 
In  Europe  the.  form  is  restricted  to  the  lower  Pkyllograptus  shale,  corre¬ 
sponding  to  the  Tetragraptus  zone 
of  the  Deep  kill,  in  which  it 
also  in  America  finds  its  principal 
development;  but,  according  to 

Fig.  64  D  idy  mo  graptus  extensus  Hall  sp.  Frag-  Lat) Worth  it  UaSSeS  here  also 

ment  of  mature  part  of  branch.  Deep  kill.  x5.25  xjcipwui  on,  it  prt&aes  ncic  aissu 


into  the  next  higher  zone  with 
D.  bifidus  and  Pkyllograptus  anna. 

Remarks.  D.  extensus  can,  in  the  material  from  the  Deep  kill,  be 
readily  distinguished  from  its  congeners  by  the  great  length  and  nearly  uni¬ 
form  width  of  the  branches  and  its  relatively  broad  thecae.  In  this  repre. 
sentative  the  genus  Didymograptus  attained  here  its  maximal  development; 
for  individuals  like  that  figured  on  plate  14  [fig.l]  may  have  reached  1  m  in 
length.  Also  in  final  width  the  Deep  kill  examples  of  the  species  pass  con¬ 
siderably  beyond  the  maxima  observed  elsewhere. 

Intermingled  with  typical  specimens  of  D.  extensus  occur  numerous 
others  which  have  the  appearance  of  those  figured  on  plate  13  [fig.l 7,  18]. 
They  are  as  a  rule  more  flexuous,  have  a  uniform 
width  (about  1.9  mm)  throughout  their  length,  and 
possess  a  constrictiform  appearance  of  the  thecae. 

As  these  are  the  principal  characters  of  Hall’s 
species  D.  con  strict  us,  we  have  no  doubt  that 

the-  latter  species  is  based  on  specimens  which  became  compressed  in  a 
certain  direction,  namely  obliquely  dorsolaterally  instead  of  laterally,  so 
that  the  frontal  or  apertural  side  of  the  thecae  is  partly  exhibited.  On  this 
account  Hall  found  also  that  the  “  common  body  occupies  a  very  small  pro¬ 
portion  of  the  entire  width,  and  its  limits  are  not  distinctly  defined.”  The  com¬ 
mon  canal  lies  in  this  mode  of  preservation  behind  the  exposed  side.  The 


Fig.  65  Constrictiform  appear¬ 
ance  of  a  branch  of  Didymo- 
graptus.  Deep  kill.  x2 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


671 

sicula  also  is  either  covered  entirely  or  only  exposed  with  its  apex,  as  in 
figures  17,  18  of  plate  13. 

As  Hall  states  that  the  types  of  D.  constrictus  have  been  associated 
with  D.  pat  ill  us,  it  is  possible  that  they  may  in  part  at  least,  represent 
the  constrietiform  mode  of  preservation  of  that  species.  The  forms,  identified 
by  other  authors  with  D.  constrictus  Hall,  may  be  based  on  the  con- 
strictiform  appearance  of  still  other  species. 

Didymograptus  nitidus  Hall  sp. 

Plate  13,  figures  1-5 ;  plate  14,  figures  5,  6 

Graptolithus  nitidus  Hall.  Geol.  Sur.  Can,  Rep’t  for  1857.  p.129 

Graptolithus  nitidus  Hall.  Canadian  Organic  Remains,  decade  2.  1865.  p  69, 
pi.  1,  fig.  1-9 

Didymograptus  nitidus  Nicholson  {pars).  Quar.  Jour.  Geol.  Soc.  1868. 
24:135 

Non  Didymograptus  nitidus  Nicholson.  Ann.  and  Mag.  Nat.  Hist,  ser.4. 
1870.  v.5,  p.342,  fig.3a-c 

?Didymograptus  nitidus  Etheridge  jr.  Ann.  and  Mag.  Nat.  Hist,  ser.4. 
1874.  14:6,  pl.3,  fig.20 

Didymograptus  nitidus  Herrmann.  Geol  Mag.  Dec.  3,  1886.  3:15 

Didymograptus  nitidus  Barrois.  Ann.  de  la  Soc.  Geol.  du  Nord.  1892. 
t.20,  p.91 

Didymograptus  nitidus  Matthew.  Roy.  Soc.  Can.  Proc.  and  Trans.  1893. 
11:114 

Didymograptus  nitidus  Elies  {pars).  Quar.  Jour.  Geol.  Soc.  1896. 

54:499-502;  p.500,  fig.19 ;  p.501,  fig.20 
Didymograptus  nitidus  Gurley.  Jour.  Geol.  1896.  4:295 
Didymograptus  nitidus  Elies  &  Wood.  Monogr.  Brit.  Grapt.  pt  1.  Pal. 
Soc.  vol.  for  1901.  p.10,  pl.l,  fig.2a-c 

Didymograptus  nitidus  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.554,556 

Description.  Primary  disk  small  (diameter  about  3  mm),  subcircular, 
tenuously  chitinous,  with  a  central  node  from  which  the  short,  thin  nerna 
proceeds.  Sicula  broad  and  short  (about  1 . 3  mm  long),  branches  diverging 
in  their  proximal  parts  under  angles  varying  between  100°  and  180°  to  a  dis- 


672 


NEW  YORK  STATE  MUSEUM 


Fig-.  63  Didymograptus  n  i t i (1  u s  Hull  *p. 
Proximal  part  of  rhabdosome.  Reverse  view. 
Deep  kill.  ,\0 


tance  of  4  to  5  mm,  then  assuming  a  horizontal  direction ;  widening  gradually 
to  a  maximal  width  of  2.4  mm  (average  but  1 . 6  mm),  attaining  each  a 
maximal  length  of  124  mm.  Thecae  closely  arranged  (11  to  13  in  10  mm), 

slightly  curved,  inclined  to  the  axis  at  an 
aimle  of  about  40°  ;  three  times  as  lomr 
as  wide,  in  contact  for  two  thirds  or  less 
in  the  proximal  and  for  three  fourths  of 
their  length  in  the  mature  portion  of 
the  branch.  Apertural  margin  slightly 
concave,  normal  on  axis  of  thecae  (form¬ 
ing  angle  of  130°  with  axis  of  branch). 

Position  and  localities.  At  the  Deep  kill  this  species  has  been  found  to 
be  restricted  to  graptolite  beds  1  and  2,  which  represent  the  Tetragraptus 
zone.  In  these  it  is  quite  com¬ 
mon.  Hall  reports  it  from  the 
shales  of  the  Quebec  group  at 
Point  Levis.  As  at  the  latter 
point  the  Tetragraptus  zone  and 
the  zone  with  D  i  p  1  o  g  r  a  p  t  u  s 

den  tat  us  are  represented,  and  the  association  with  species  from  the  latter 
zone  is  always  carefully  mentioned,  it  is  to  be  inferred  that  Hall’s  types  were 

associated  with  the  major  fauna,  that  of  the 
Tetragraptus  zone.  Strangely  enough  Ami 
[1889,  p.ll6k],  Lapworth  [1886,  p.184]  and 
Gurley  [1896,  p.295]  do  not  cite  this  species 
as  having  been  found  in  the  collections  of 
graptolites  of  the  Quebec  group,  which  they 
investigated.  Lapworth’s  material  did  not  contain  representatives  of  the 
Tetragraptus  zone;  and  in  Ami’s  lists  it  has  most  probably  been  referred  to 
D.  extens  u  s,  to  which  it  is  most  similar.  Matthew  cites  this  species  from 
horizon  3d  of  the  St  John  group  in  New  Brunswick.  In  Great  Britain  the 
form  is  widely  distributed  in  the  Middle  Skiddaw  slates  of  the  Lake  district. 


Fig.  67  Didymograptus  nitidus  Hall  up.  idem.  Shows 
point  of  origin  ot  first  theca  and  growth  lines.  Deep  kill.  x5.25 


Fig.  68  Didymograptus  nitidus 
Hall  up.  Distal  part  of  branch.  Deep  kill, 
xo.  Sio 


UR APTO LIT E S  OF  NEW  YORK.  PART  1 


673 


corresponding  to  the  Tetragraptus  beds  of  the  Deep  kill,  in  the  Middle  Arenig 
of  St  David’s,  in  the  Lleyn  peninsula  of  Wales  and  in  Shropshire.  In  Scandi- 
navia  the  species  does  not  appear  to  have  as  yet  been  clearly  recognized ; 
Herrmann  \loc.  cii. J  cites  it  as  “doubtfully  in  Phyllograptus  shales,  Norway.” 
Barrois  describes  D.  nit  id  us  as  common  in  the  graptolite  schists  at 
Boutoury  near  Cabrieres ;  and  the  younger  Etheridge  records  it  from  Castle- 
maine  in  Victoria,  Australia,  but  his 


Fig'.  69  Didymograptus  nitidus  Hall  sp. 
ragment  of  branch,  showing  different  aspects  of 
lecne  due  to  different  direction  of  compression. 
"  Deep  kili.  x  .5.25 

observable  in  a  considerable  number  of 

specimens.  It  is  found  close  to  the  apex  of  the  sicula,  so  that  the  latter 
appears  to  have  been  as  a  rule  attached  by  only  a  very  short  nema  and  even 
without  the  intercalation  of  such,  as  in  figure  3.  I  have  not  observed  any 
disks  on  larger  rhabdosomes,  but  this  is  possibly  due  to  the  fact  that  I  did  not 
find  any  larger  specimens  so  isolated  and  unencumbered  by  other  fossils  on 
smooth  surfaces  that  I  was  able  to  distinguish  these  delicate  appendages. 

This  species  approaches  D.  p  at  u  1  u  s  on  one  hand,  and  D.  extensus 
on  the  other,  and  it  is  difficult  to  assign  some  forms  to  one  of  the  three.  This 
is  specially  true  in  regard  to  the  differentiation  of  the  closely  allied  species  D. 

nitidus  and  D.  p  a  t  u  hi  s.  The  closer  arrange¬ 
ment  of  the  thecae  in  D.  nitidus  and  the 
greater  width  of  the  branches  of  D.  p atulus 

Fig.  70  Didymograptus  ni¬ 
tidus  Hall  sp.  Fragment  of  branch. 

The  periderm  is  lost  and  the  form  of 

the pyri1e^ning?a Deep wfh °x 7 by  greater  number  of  thecae  within  a  certain  space 

and  the  more  rapid  widening  of  the  branches  will 
also  distinguish  the  typical  D.  nitidus  from  D.  extensus. 

A  few  of  the  specimens  which  we  had  to  refer  to  this  species  [fig.  5] 
greatly  surpass  in  length  and  width  of  the  branches  attained  the  examples 
described  from  Canada  and  Great  Britain.  At  the  same  time  they  show  just 
a  little  looser  arrangement  (11  in  10  mm)  than  the  typical  D.  nitidus, 
but  still  a  greater  number  of  thecae  in  a  unit  than  1).  extensus  and  D. 


are  the  principal  distinctive  characters.  The 


identification  is  doubted  by  Lapworth, 
Elies  and  Wood. 

Remarks.  The  primary  disk  is  ti 


674 


NEW  YORK  STATE  MUSEUM 


p  a  t  u  1  u  s.  As  the  form  of  the  thecae  does  not  permit  a  reference  to  either  of 
the  two  last  named  species,  the  one  having  broader  and  shorter,  the  other  more 
inclined  and  curved  thecae,  it  has  been  with  us  a  question  of  either  creating 
a  new  specific  term  or  extending  the  definition  of  D.  n  i  ti  d  u  s  sufficiently  to 
include  these  forms.  We  have  preferred  the  latter,  as  the  two  are  connected 
by  such  easy  gradations  that  it  would  be  impossible  sharply  to  divide  them. 
As,  however,  in  other  localities  the  species  is  evidently  restricted  to  its  typical 
expression,  the  fact  of  the  variation  calls  for  recognition,  and  we  propose  to 
designate  these  larger  forms  with  somewhat  less  closely  arranged  thecae  as  the 
variety  D.  n  i  t  i  d  u  s  var.  grandis. 


Didymograptus  patulus  Hall  sp. 

Plate  13,  figures  8,  9;  plate  14,  figure  7 

Graptolithus  patulus  Hall.  Geol.  Sur.  Can.  Rep’t  for  1857.  1858.  p.131 
Graptolithus  patulus  Hall.  Canadian  Organic  Remains,  decade  2.  1865. 

p.71,  pl.l,  fig.10-15 

Non  Didymograptus  patulus  Nicholson.  Qnar.  Jour.  Geol.  Soc.  1868. 
24:135 

Non  Didymograptus  patulus  Nicholson  (pars).  Ann.  and  Mag.  Nat.  Hist. 
ser.4.  1870.  5:340,  pi. 7,  fig.la 

Didymograptus  patulus  Hopkinson.  Quar.  Jour.  Geol.  Soc.  1875.  31:644, 

pi. 33,  tig.4a-e 

Didymograptus  patulus  Linnarsson.  Sver.  Geol.  Und.  Afh.  och  Upps.  1879. 
ser.C,  no.31,  p.5 

Didymograptus  p a t u  1  u  s  Brogger.  Die  sil.  Etagen  2  and  3.  1882.  p.39 

Didymograptus  pa  t  ul  us  Herrmann  (pars).  Geol.  Mag.  Dec.  3,  1886.  3:14 

Didymograptus  patulus  Matthew.  Royal  Soc.  Can.  Proc.  and  Trans.  1893. 
10:98 

Didymograptus  patulus  Matthew.  Royal  Soc.  Can.  Proc.  and  Trans.  1894. 
11:114 

Didymograptus  patulus  Gurley.  Jour.  Geol.  1896.  4:295 

Non  Didymograptus  patulus  Elies.  Quar.  Jour.  Geol.  Soc.  1898.  54:504, 

fig. 22,  23 

O 

Non  Didymograptus  patulus  Tdrnquist.  Lunds  Lniv.  Arsskrift.  1901.  Bd37, 
Af.2,  Nr  5,  p.15,  pl.2,  fig.1-6 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


675 


D  i  d  y  eq  o  gr  ap  t  us  patulus  Eiles  &  Wood.  Monogr.  Brit.  Grapt.  ptl.  Pal.  Soc. 

vol.  for  1901.  p.13,  pl.l,  fig.8a-c 

Didymograptus  patulus  Ruedemann.  1ST.  Y.  State  Paleontol.  An.  Rep’t. 

1902.  p.556 

Description.  Primary  disk  large,  subcircular,  very  tenuous  [fig.  9]. 
Nema  very  short  (.3  mm)  or  absent  [fig.  9].  Sicula  inconspicuous,  about 
2  mm  long.  The  first  theca  originates  a  little  above  the  middle  of  the  sicula, 
the  second  near  its  aperture.  The  branches  horizontal,  nearly  straight, 
attaining  a  length  of  5  cm  and  more,  narrow  in  the  proximal  part  (.7  mm), 
but  widening  rather  rapidly  to  a  maximal  width  of  2.6  mm  and  narrowing 
again  at  the  growing  end.  Thecae  numbering 
10  to  12  in  10  mm,  curved  and  inclined  at  40° 
in  their  proximal  and  60°  in  their  distal  part, 

Fig.  71  Didymograptus  patulus 
Hall  sp.  Young  rhabdosome.  Obverse 
view.  Deep  kill,  x  5.25 

thirds  to  three  fourths  of  their  length.  Outer 

margin  distinctly  concave,  apertural  margin  straight  to  slightly  concave, 
mucronate  at  the  lower  end,  forming  an  angle  of  40°  to  50°  with  the  axis 
of  the  thecae. 

Position  and  localities.  D.  patulus  is  at  the  Deep  kill  very  common 
in  graptolite  beds  1  and  2,  representing  the  Tetragraptus  zone,  but  apparently 
does  not  persist  to  the  zone  with  D.  bifidus.  Hall  received  his  type  from 
the  Quebec  group  at  Point  Levis.  Gurley  records  it  from  the  Main  Point 
Levis  zone,  which  _  corresponds  to  our  Tetragraptus  zone.  Ami  does  not 
mention  it  in  his  list,  but  Matthew  found  it  to  be  common  in  association 
with  D.  n  i  t  i  d  u  s  in  division  3d  of  the  St  John  group. 

In  England  other  species  have,  as  Lapworth,  Elies  and  Wood  assert, 
been  repeatedly  mistaken  for  this  type.  According  to  these  authors,  it  occurs 
in  the  Lower  Llanvirn  beds  of  the  St  David’s  district  in  Wales,  associated 
with  D.  bifidus,  D.  nicholsoni,  etc.;  in  the  Middle  and  Upper 
Arenig  of  the  Shelve  district  in  Shropshire ;  and  at  Kiltrea  near  Ennisworthy 
in  Ireland.  It  appears,  hence,  in  Great  Britain,  to  find  its  principal  develop¬ 
ment  in  a  higher  horizon  than  in  America.  In  the  Skiddaw  slates  it  seems  to 


four  times  as  long  as  wide,  in  contact  two 


676 


NEW  YORK  STATE  MUSEUM 


"be  absent.  Brogger  cites  it  from  the  Phyllograptus  shale  of  Krekling  in  the 
region  of  Christiana  (according  to  Herrmann  Lower  Phyllograptus  shale),  and 
Herrmann  adds  Scania  and  West  Gothland.  Tdrnqmst’s  identification  of 
this  species  among  the  forms  from  the  last  named  provinces  is  however  not 
recognized  by  the  monographers  of  the  English  graptolite  fauna,  and  its 
occurrence  in  Sweden  is  hence  still  doubtful. 

Remarks.  The  reference  list  of  the  species  shows  distinctly  by  the  num¬ 
ber  of  erroneous  identifications  cited  how  difficult  of  exact  recognition  this 
form  is.  The  writer’s  experience  verifies  this  fact;  for,  while  in  the  lower 
graptolite  beds  of  the  Deep  kill  a  majority  of  the  specimens  readily  suggest 


by  their  habit  that  they  might  belong  to  this  species,  a 


comparison  by  measurements,  with  the  types  and  the  data 


fir.72  Did y mo-  given  by  Hall,  brings  out  the  fact  that  nearly  all  specimens 


graptus  patu- 
lus  Hall  sp.  Frag¬ 
ment  of  branch. 
Deep  kill.  x2 


oscillate  in  their  characters  between  the  typical  D  .  p  a  t  ul  u  s 
and  D .  n  i  t  i  d  u  s  .  Hall  states  that  the  former  species 


differs  from  the  latter  “  in  the  greater  extent  of  the  stipes,  and  in  their 
almost  lineal  character”  and  adds:  “The  form  of  the  denticles  and  their 
angle  with  the  axis,  as  well  as  their  proportional  distance,  are  distinctive 
characters.”  Our  material  contains  specimens  of  D.  nit  id  us  with  stipes 
that  are  longer  and  as  straight  as  those  ofD.  patulus.  The  graptolites, 
here  referred  to  D .  patulus,  have  wider  and  more  rapidly  widening 
branches,  more  inclined  and  curved  thecae  with  mucronate  apertural  margins, 
but  the  thecae  exhibit  constantly  a  somewhat  closer  arrangement  than  Hall 
has  recorded  for  D  .  patulus,  and  at  the  same  time  they  are  not  so  closely 
arranged  as  in  D .  n  i  t  i  d  u  s.  Our  forms  have  also  more  rapidly  expanding 
branches  which  attain  a  greater  width  than  either  Hall’s  or  the  English  types. 

Hall  stated,  further,  that  the  inclination  of  the  thecae  in  D.  patulus 
is  60° ;  the  thecae  of  our  material  have  an  initial  inclination  of  40°,  which 
however  increases  to  60°  toward  the  aperture.  The  drawings  of  Hall’s  types 
exhibit  the  same  degree  of  curvature  of  the  outer  margin  of  the  thecae. 

Lapworth,  Elies  and  Wood  also  comment  on  the  resemblance  of  D . 
patulus  and  D  nitidus,  specially  in  the  proximal  region,  and  cite 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


G77 


Fig.  73  Didymograptus  patulus 
Hall  sp.  Fragment  of  distal  portion  of  branch. 
Deep  kill,  x  5.25 


the  smaller  number  of  thecae  in  a  unit  of  length  and  the  general  absence  of 
curvature  in  the  branches  of  D  .  patulus  as  distinctive  characters.  Their 
specimens  of  the  latter  species  have  a  looser  arrangement  than  ours  (9  to  10 
in  10  mm),  while  the  thecae  in  the  drawings  [p.14]  do  not  exhibit  the  curva¬ 
ture  and  inclination  described  by  Hall  as  characteristic  of  that  species. 

These  facts  indicate  that  there  is  a 
considerable  number  of  varieties  grouping 
themselves  around  and  between  the  typical 
forms  of  D  .  patulus  and  D  .  n  i  t  i  d  u  s . 

We  have  observed  a  primary  dish 
which  in  the  specimen  figured  [fig.  9]  is 
subcircular,  fairly  well  outlined,  has  a  diameter  of  about  12  mm  and  though 
showing  but  a  trace  of  carbonaceous  substance,  is  distinctly  set  off  from  the 
surrounding  surface  by  its  smoothness  and  depressed  margin.  Like  the 
primary  disks  of  other  forms,  it  possesses  in  the  center  a  small,  somewhat 
more  projecting  circular  portion.  The  apex  of  the  sicula  lies  upon  the  apex 
of  this  projection  and  was  hence  evidently  fastened  to  the  disk  either  by  a 
very  short  nema  or  without  the  intercalation  of  one.  Since  in  hundreds  of 
otherwise  perfect  specimens  of  I)  .  patulus  the  sicula  shows  no  trace  of 
a  nema,  I  feel  satisfied  that  this  species  was  closely  attached  to  the  primary 
disk,  and  not  suspended  by  means  of  a  long  nema  as  I).  (g  i  b  b  e  r  u  1  u  s) 
caduceus. 


Didymograptus  similis  Hall  sp. 

Plate  14,  figures  25-29 

Didymograptus  similis  Hall.  Canadian  Organic  Remains  decade  2.  1865. 

p.78,  pi. 2,  fig.1-5 

Didymograptus  similis  Gurley.  Jour.  Geol.  1896.  4:295 
Didymograptus  similis  Ruedemami.  N. Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.566,  567 

Description.  Nema  and  primary  disk  not  observed.  Sicula  small  and 
inconspicuous,  about  1.8  mm  long.  Branches  diverging  at  180°,  maximal 
length  attained  unknown  (longest  fragment  observed  45  mm);  widening 


678 


NEW  YORK  STATE  MUSEUM 


Fig.  73  Didymograptus 
similis  Hall  sp.  Very  early 
growth  stage  of  rhabdosome. 
Obverse  view.  Shows  sicula  and 
first  thecae.  Deep  kill  x  5 


rapidly  from  .8  mm  in  the  proximal  part  to  the  maximal  width  (about 
1.8  mm),  which  is  maintained.  First  and  second  thecae  originate  near  the 
apex  of  sicula.  Thecae  numbering  9  to  10  in  10  mm,  relatively  short  and 
wide  tubes;  width  one  third  to  one  half  of  the  length;  inclined  at  an  angle 
of  about  30°,  their  outer  margin  straight  or  slightly  concave,  free  for  one 

third  to  one  fourth  of  their  length  ;  apertural  margin 
straight,  forming  with  the  axis  of  branch  an  angle  of 
about  120°  (normal  on  axis  of  theca). 

Position  and  localities.  Common  in  graptolite 
beds  3  and  5  of  the  Deep  kill  section  (zone  with 
D.  bifid  us)  and  very  rare  in  the  beds  trans¬ 
itional  from  this  zone  to  that  with  Diplograptus 
dentatus,  on  Mt  Moreno  near  Hudson.  The  originals  of  the  species 
were  also  taken  from  the  same  zone  (Phyllograptus  anna  zone),  three  miles 
above  the  St  Anne  river  in  Canada.  The  form  has  not  been  reported  from 
other  localities. 

Remarks.  This  species,  which  seems  in  America  to  be  restricted  to  the 
zone  with  Phyllograptus  anna  and  D.  bifidus,  has,  on  account  of 
its  short  and  broad  thecae,  been  compared  by  Hall  with  D.  Sagittarius 
from  the  Normanskill  shades.  With  associated  congeners  it  has  little 
similarity,  but  reminds  sometimes  of  young  forms 
of  D .  extensus,  from  which  it  can  be  distin¬ 
guished  by  the  less  closely  arranged  and  somewhat 
differently  shaped  thecae.  It  is  however  extremely 
similar  to  the  Swedish  species  D.  suecicus 
Tullberg  and  D.  decens  Tornquist.  From  the 
careful  descriptions  of  the  former  species  published  by  Tullberg  [1880,  p.43] 
and  by  Tornquist  [1901  ;  p.13],  and  of  the  latter  by  Tornquist  [1891,  p.18] 
it  can  be  inferred  that  D .  similis  tallies  in  all  important  characters  and 
completely  in  the  measurements  with  these  two  forms;  for  their  angle  of 
divergence  is  180°,  number  of  thecae  9  to  10  in  10  mm,  the  angle  of  inclination 
30°.  Also  the  form  and  length  of  the  sicula  and  the  form  of  the  thecae  are 


Fig.  74  Didymograptus 
similis  Hail  sp.  Young  rhab¬ 
dosome.  Reverse  view.  Deep 
kill.  x(>.5 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


679 


alike.  D  .  suecicus  and  D .  decens  are  hardly  to  be  distinguished  from 
each  other.  Professor  Tornquist,  the  author  of  the  latter  species,  doubts 
himself  whether  they  are  really  distinct  and  mentions  the  apparent 
occurrence  of  transitional  forms.  The  facts,  that  E>.  suecicus  has  over¬ 
lapping  thecae  which  widen  more  toward  the  aperture,  and  that  their  outer 
margins  are  distinctly  curved  and  free  for  but  one  third,  are  cited  as  affording 
distinctive  characters.  If  we  accept  these  differences  as  of  specific  value,  D  . 
suecicus  will  have  to  be  regarded  either  as  a  vicarious  form  of  D  . 
similis  or,  1  believe,  as  really  identical  with  the  latter  and  D.  decens  as 
a  very  closely  related  form.  Tullberg  held  his  D  .  suecicus  to  be  nearly 
related  to  D.  nitidus  Hall.  The  latter  differs,  however,  essentially  in  the 
rate  of  widening  of  the  branches  and  specially  in  the  much  closer  arrange¬ 
ment  of  the  thecae. 

D.  suecicus  occurs,  according  to  Tornquist,  abundantly  in  the  third 
zone  of  the  Phyllo-Tetragraptus  beds  (zone  with  Phyllograptus 
d  e  n  s  u  s),  and  more  sparingly  in  the  second  zone  (zone  with  D.  balticus). 
Hence  it  holds  there  about  the  same  level  in  the  lower  graptolite  shales  as 
D .  similis  in  America  and  is  a  member  of  a  corresponding  faunule. 

Didymograptus  gracilis  Tornquist 

Plate  14,  figures  15-21 

Didymograptus  gracilis  Tornquist.  Undersokningar  ofver  Siljansomradets 
Graptoliter  I  (Aftryck  ur  Lunds  Univ.  Arsskrift.  Tom.  26).  1891.  p.17,  pl.l, 

fig.9-12 

Didymograptus  gracilis  Holm.  Geol.  Foren.  Stoekk.  Fork.  Bd  17,  H  3,  1895. 
pl.l,  fig. 7,  8 

Did  y m  o gr  apt  u  s  g r  aci  1  i  s  Elies.  Quar.  Jour.  Geol.  Soc.  1895.  54:506 

Didymograptus  gracilis  Elies  &  Wood.  Monogr.  Brit.  Grapt.  ptl.  1901. 
p.24,  pi. 2,  fig. 2 

Didymograptus  (Leptograptus)sp.  nov.  Ruedemann.  N.  Y.  State  Paleontol. 
An.  Rep.  1902.  p.589,  fig.17 

Non  Graptolites  (Didymograptus)  gracilis  McCoy.  Geol.  Sur.  Victoria. 
Prodr.  Pal.  Victoria,  decade  2.  1875.  p.35 


GSO 


NEW  YOKE  STATE  MUSEUM 


Iii  the  base  of  graptolite  bed  3,  the  lowest  outcrop  of  the  zone  with  D. 
b  i  f  i  d  u  s,  several  specimens  of  ail  extremely  delicate  Didymograptus  were 
collected.  These  differ  in  no  way  from  a  species  first  noticed  in  Sweden. 
We  give  here  a  translation  of  the  original  description  of  the  species. 

From  an  almost  uniformly  thick  sicula  of  1  mm  in  length  the  two  branches 
diverge  at  distinctly  different  hights,  the  one  almost  from  the  middle,  the  other 
from  the  upper  end.  Above  these  points  of  divergence  the  aperture  of  the 
sicula  runs  obliquely  upward,  so  that  it  projects  with  a  triangular  tooth 
beyond  the  upper  branch.  The  branches  are  of  uniform  width,  .2  to  .3  mm 
wide,  and  diverge  almost  at  right  angles  from  the  sicula,  but  are  irregularly 
bent  in  their  continuation.  Within  a  space  of  10  mm  6  to  8  thecae  are  con¬ 
tained.  These  are  long  and  narrow,  with  the  periderm  compressed,  widening 
toward  the  aperture  to  about  double  the  width.  The  outer  wall  of  the  thecae 
is  slightly  concave,  sometimes  almost  straight;  it  forms  a  very  acute  angle 
with  the  dorsal  margin.  The  apertural  margin  is  perpendicular  on  the  dorsal 
margin.  Sometimes  I  believe  I  have  seen  a  short  internal  canal.  The  length 
of  the  branches  is  unknown,  but  was  certainly  15  to  20  mm  and  probably 
more. 

Occurs  in  Phyllograptus  shale  at  Skat.tungbyn.  Fragments  of  branches 
are  very  common  upon  certain  shales. 

To  this  careful  description  we  need  only  to  add  in  way  of  enlargement 
that  the  branches  are  horizontal  in  their  proximal  part  for  the  length  of  about 
three  thecae  and  then  mostly  become  gently  reclined,  a  feature  also  apparent 
in  Tornquist’s  drawings,  or  become  flaccid  ;  that  the  thecae  are  three  to  eight 
times  as  long  as  wide,  their  slenderness  increasing  distally,  wrhere  the  greater 
part  of  the  thecae  appears  as  a  very  gradually  widening,  hair-fine  tube ;  and 
that  the  angle  of  inclination  of  the  thecae  is  not  more  than  5°  in  the  mature 
portion  of  the  branches. 

Position  and  localities.  This  species  is  not  infrequent  in  graptolite  bed  3 
(the  base  of  zone  with  D.  b  i  f  i d  u  s 1),  where  it  is  associated  with  Gronio- 
graptus  geo  m  etricus  and  D.  nan  u  s,  and  it  has  also  been  found  to 
occur  still  rarely  in  the  beds  at  Mt  Moreno,  which  contain  a  fauna  transitional 
from  this  zone  to  that  with  Diplograptus  den  tat  us.  Tornquist 


1  In  the  Report  of  the  State  Paleontologist  for  1901,  p.556,  this  form  has,  as 
D.  (Leptograptus)  sp.,  been  erroneously  cited  from  graptolite  bed  2. 


GRAPTOLITES  OF  NEW  YORK,  FART  1 


GS1 


describes  it  from  the  Phyllograptus  shales  of  Skattungbyn  in  Dalarne, 
Sweden. 

Remarks.  This  is  by  all  means  the  most  delicate  and  most  attenuated 
species  of  Didymograptus  which  we  have  noticed  in  the  New  York  fauna  or 
found  recorded  from  other  regions.  The  tendency  toward  the  development  of 
long  slender  thecae  and  narrow  flaccid  branches,  which  appears  first  in 
Goniograptus  perflexilis,  has  here  apparently  reached  its  most  typi¬ 
cal  expression  and  also  its  termination.  The  distal  portions  of  the  rhabdosomes 
are  frequently  so  fine  that  they  are  barely  noticeable  with  the  naked  eye,  and 
the  lithographer  did  not  produce  these  in  their  actual  thinness  for  fear  the 
lines  could  not  be  printed.  The  enlargement  gives  a  better  idea  of  this 
slenderest  of  all  graptolites. 

It  has  been  stated  in  the  preliminary  paper  on  the  Deep  kill  fauna,  cited 
above,  that  the  earlier  thecae  of  this  form  are  considerably  shorter  than  the 
later  ones  (text  p.538),  and  the  phylogenetic  significance  of  this  feature  has 
been  pointed  out.  It  was  considered  as  indicating  derivation  of  the  species  of 
Didymograptus  with  long,  narrow  thecae  from  forms  with  shorter  and  broader 
thecae.  The  same  difference  in  the  thecae  is  shown  on  figure  11  of  Tullberg’s 
drawings.  In  the  Deep  kill  material  the  earlier  thecae  have  a  length  of  but 
.  8  mm,  while  the  later  ones  attain  2  mm  in  length.  These  are  six  to  eight 
times  as  long  as  wide  and  appear  tubular  for  two  thirds  of  their  length.  The 
more  proximal  thecae,  however,  agree  well  with  the  enlargement  given  by 
Tullberg. 

While  our  specimens,  in  the  slenderness  of  the  mature  branches,  the  long 
tubular  character  of  the  thecae,  their  small  overlap  and  inclination,  seem  to 
represent  an  extreme  development  of  the  characters  described  by  Tornquist, 
or  rather  go  beyond  the  typical  Swedish  form  in  development,  the  form 
referred  to  this  species  in  England  has  more  rapidly  widening  thecae  and  a 
correspondingly  greater  angle  of  inclination  than  the  Swedish  type  and 
varies  hence  in  the  opposite  direction  to  that  of  the  Deep  kill  form. 


082 


NEW  YORK  STATE  .MUSEUM 


Didymograptus  ellesi  sp.  nov. 

Plate  14,  figures  23-24 

Didymograptus  (Leptograptus)  sp.  nov.  {pars)  Ruedemann.  N.  Y.  State 
Paleontol.  An.  Rep’t.  1902.  p.589. 

Description.  Primary  disk  and  nema  not  observed.  Sicula  relatively 
long,  attaining  a  length  of  1.2  mm,  slender,  very  conspicuous  [fig.23]  on 

account  of  the  slender  character 
of  the  rhabdosome.  Point  of 
gemmation  of  first  and  second 

Fig.  75  Didymograptus  e  1 1  e  s  i  sp.  nov.  Sicula  and  part  thecae  not  observed,  that  of 
of  one  branch.  Obverse  view.  Deep  kill.  x7  > 

the  first  theca  apparently  in  the 
apical  half  of  the  sicula.  Branches  originating  near  the  aperture  of  the  sicula 
at  different  levels  of  the  same,  but  slightly  curved,  of  somewhat  rigid  appear¬ 
ance,  slightly  declined  (angle  of  divergence  quite  uniformly  170°),  very  thin, 
very  gradually  widening  from  a  proximal  width  not  quite  .2  mm  to  one  of  .4 
mm;  attaining  a  length  of  14mm  or  more.  Thecae  very  slender,  widening 
but  very  little  toward  the  aperture,  numbering  10  to  12  in  10  mm  ;  three  times 
as  long  as  wide,  inclined  at  an  angle  of  8°  to  10° ;  overlapping  about  one  eighth 


Fig.  76  Didymograptus  ellesi  sp.  nov.  Enlargement  of  a  branch 
of  the  specimen  reproduced  on  pi.  14,  fig.  22.  Deep  kill.  x6 


of  their  length,  the  outer  or  apertural  margins  straight,  the  latter  perpendicular 
on  the  axis  of  the  theca. 

Position  and  locality.  Found  on  a  single  surface  at  the  base  of  bed  3  at 
the  Deep  kill,  associated  with  D.  nanus  and  D.  gracilis. 

Remarks.  This  form  is  readily  distinguished  from  the  associated,  simi¬ 
larly  delicate  D.  gracilis  by  the  more  rigid  expression  and  uniform,  slightly 
declined  direction  of  the  branches.  Its  nearest  relations  are  clearly  with  D  . 
af finis  Nicholson  among  the  types  of  Didymograptus  and  with  Bryo- 
graptus  lapworthi,  here  described,  among  the  older  multiramous  forms 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


683 


From  the  former  it  differs  by  the  somewhat  closer  arrangement  of  the  thecae 
and  their  smaller  angle  of  inclination.  To  the  latter  it  bears  such  a  remark- 
able  similarity  of  habit  that  a  genetic  connection  of  the  two  can  not  be  gain¬ 
said  [p.557]. 


Didymograptus  acutidens  (Lapworth  ms.  em.  Elies  <fc  Wood) 

Plate  13,  figure  15 

Didymograptus  affinis  Hopkinson.  Quar.  Jour.  Geol.  Soc.  1875.  v.31, 

pi  33,  fig.6b,c 

Didymograptus  acutidens  (Lapworth  ms  em.  Elies  &  W ood).  Monogr.  Brit. 
Grapt.  ptl.  Pal.  Soc.  vol.  for  1901.  p.25,  pi. 2,  fig.3a-d 


Description.  Only  one  specimen  of  this  species  has  been  observed.  This 
presents  the  following  characters.  Primary  disk  and  nema  not  present. 
Sicula  slender,  about  1.2  mm  long,  branches  originate  at  ..  . 

slightly  different  levels,  the  first  theca  curving  away  from  ^ 
a  point  about  two  thirds  the  length  of  the  sicula  from  Fig.  77  Didymo- 

0  graptus  acutidens 

its  apex  and  the  second  theca  nearer  to  the  aperture.  tlon'ofThe Molkme.1  ob¬ 
verse  view.  Deep  kill,  xo 

Mature  length  of  branches  not  observed,  branches  diverg¬ 
ing  at  an  angle  of  180°;  straight,  but  not  rigidly  so,  very  slender,  .4  mm 
wide  in  the  proximal  portion  and  attaining  a  width  of  .  6  mm.  Thecae 
numbering  11  in  10  mm,  four  times  as  long  as  wide,  in  contact  for  one 
third  to  one  half  of  their  length;  inclination  15°.  Outer  margin  straight; 
apertural  margin  concave  with  a  denticle. 

Position  and  localities.  A  single  specimen  has  been  found  on  a  slab 
with  Phyllograptus  anna,  Dichograptus  octobrac  hiatus, 
etc.,  belonging  to  the  lower  part  of  the  zone  with  D  .  b  i  f  i  d  u  s  .  In  Great 
Britain  the  same  species  occurs,  according  to  the  monograph  of  the  British 
graptolite  fauna,  in  the  Lower  Llanvirn  of  the  St  David’s  district  in  Wales 
and  of  south  Shropshire ;  hence  at  about  the  same  level  as  on  this  side  of  the 
Atlantic. 

Pemarhs.  This  form  is  in  its  habit  so  similar  to  Bryograptus 
lap  w  orthi,  described  above,  that,  having  but  one  specimen,  I  would  not 


NEW  YORK  STATE  MUSEUM 


have  ventured  to  describe  it  as  belonging  to  a  different  species.  The  fact  how¬ 
ever,  that  this  specimen  occurs  in  a  zone  where  Bryograptus  lap- 
worthi  has  become  extinct,  and  that  it  agrees  still  more  closely  with  a 


species  of  Didymograptus  occurring  in  the  same 
zone  in  Great  Britain,  justifies  the  identifica¬ 
tion.  From  Bryograptus  lap  worth  i 
the  specimen  differs  by  the  somewhat  closer 


Fig.  78  Didymograptus  acutidens 
L„  E.  &  W.  Fragment  of  branch.  Deep 
kill.  x5 


arrangement  of  the  thecae,  the  more  prominent  denticulations  of  the  apertural 
margins  and  the  greater  angle  of  divergence  of  the  branches. 


Didymograptus  cuspidatus  sp.  nov. 

Plate  13,  figure  16 

Description.  The  single  specimen  of  this  species  observed  presents  the 


following  characters.  Primary  disk  and  nema  not  present.  Sicula  short, 
apparently  not  longer  than  .  8  mm,  and  inconspicuous.  Branches  originate 
suborally,  at  slightly  different  levels ;  diverge  at  first  at  an  angle  of  1 40°,  and 
become  later  subhorizontal.  Length  of  mature  branches  has  not  been 
observed  ;  their  width  is  at  first  very  small  (.4  mm),  but  increases  rapidly  to 
the  double  dimension.  Thecae  number  11  to  12  in  10  mm,  are  slender  (three 
times  as  long  as  wide  in  the  proximal  portion 


of  the  branch),  but  rapidly  become  wider,  their 
apertural  width  being  in  later  thecae  one  half  the 
length ;  they  are  hardly  in  contact  in  the  early 


tv  xjmy  mograpius  cus¬ 
pidatus  sp.  nov.  Proximal  portion 
of  rhabdosome.  Ash  hill  quarry  at 
Mount  Moreno.  x5 


portion  of  the  branch  and  overlap  later  to  about  Mount  Moreno.  xs 
one  third  to  one  half  of  their  length.  The  inclination  of  the  early 
thecae  is  only  about  18°;  it  increases  to  about  40°  in  the  apertural  part  of 
the  later  thecae.  The  latter  is  characteristically  prominent,  giving  the  thecae 
a  cuspidate  appearance ;  the  outer  margin  is  straight  in  the  proximal  portion 
of  the  thecae  and  concave  in  the  apertural;  the  apertural  margin  slight] v 
convex  in  the  outer  and  concave  in  the  inner  part;  on  the  whole  appearing 
straight  and  vertical  on  the  axis  of  the  thecae. 

O 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


685 


Position  and  locality.  In  the  shales  with  Diplograptus  den  tat  us 
at  Mt  Moreno  near  Hudson. 

Remarks.  This  species  is  nearest  related  to  D .  acutidens  Lap- 
worth,  of  which  it  presents  the  characteristic 
features  in  a  further  developed  stage.  As  it  also 
succeeds  the  latter  in  geologic  time,  it  may  well 
be  considered  as  a  descendant  of  it.  It  differs 
from  D.  acutidens  most  markedly  in  the  prominence  of  the  apertural 
portion  of  the  thecae,  which  in  most  thecae  appears  cuspidate  instead  of 
acutely  dentate,  as  in  D .  acutidens.  This  is  due  to  a  widening,  often 
somewhat  abrupt,  of  the  thecae  in  their  last  growth  stage. 


Fig.  80  D  i  d  y  m  o  g  r  a  p  t  u  s  c  u  s  p  i- 
ilatus  sp.  now  Fragment  of  brunch. 
Ashhill  quarry  at  Mt  Moreno.  x5 


Didymograptus  nicholsoni  Lapworth 
var.  planus  Elies  <fe  Wood 

Plate  13,  figures  10-14 

Didymograptus  nicholsoni  var.  planus  Elies  &  Wood.  Monogr.  Brit. 
Grapt.  ptl.  Pal.  Soc.  vol.  for  1901.  p.29,  pi. 2,  fig.5a,  b 

Description.  Primary  disk  and  nema  unknown.  Sicula  small  (about 
1.6  mm  long),  relatively  broad.  Branches  straight,  or  very  slightly  curved,  of 

rigid  appearance,  both  together  forming  a  straight 
line  (angle  of  divergence  180°) ;  short  (maximal 
length  observed  28  mm)  ;  narrow,  of  nearly  uniform 
nfe^o8i1so?ildLa“^l ?o“ppia-  width  (about  1.1mm)  after  the  sixth  theca  (width 

nusE.  &W.  Proximal  portion  . 

Deep  wn.^xT16,  0bverse  vicw-  in  proximal  part  .5  mm).  Thecae  numbering  10  to 

11  in  10  mm,  narrow,  four  times  as  long  as  wide, 
inclined  at  20°,  in  contact 
for  but  one  fourth  to 


one  third  of  their  length. 

O 

straight. 


Fig.  S:2  Didymograptus  nicholsoni 
E.  &  W.  Fragment  of  branch.  Deep  kill.  x7 


Lupw.  var.  planus 

^  E.  &  w.  fragment  of  branch.  Deep  kill.  x7 

Outer  margins 

Apertural  margins  slightly  concave,  normal  on  axis  of  theca ;  two  thirds  the 
width  of  the  branch. 


686 


NEW  YORK  STATE  MUSEUM 


Position  and  localities.  Rare  in  graptolite  bed  2  (Tetragraptus  zone)  ; 
associated  on  slabs  with  Tetragraptus  fruticosus,  T.  s  i  m  i  1  i  s,  T. 
pygmaeus  and  Dichograptus  octobrachiatus.  The  authors  of 
the  variety  report  it  from  the  Upper  Skiddaw  slates  of  Outerside  in  the  Lake 
district  of  North  England. 

Pemarhs.  I  have  hesitated  for  some  time  to  identify  my  material  with 
the  variety  from  the  Skiddaw  slates,  for  the  reason  that  the  latter  has  thus  far 


Fig.  S3  Didymograptus  nicholsoni  Lapw.  par.  planus  E.  &  W.  Proximal  portion 
of  rhabdosome.  Reverse  view.  Deep  kill.  x4 


been  found  in  a  higher  horizon  ;  but  I  have  failed  to  find  any  important  dis¬ 
tinguishing  characters,  and  the  branches  and  thecae  appear  to  agree  with  the 
British  types  in  all  details.  The  somewhat  smaller  figures  for  the  size  of  the 
sicula  in  our  material  may  be  due  to  an  incomplete  preservation  of  the  apical 
end.  The  branches  appear  to  originate  in  our  specimens  [ see  figure  81]  very 
close  to  the  apex  of  the  sicula  and  diverge  from  the  latter  suborally. 

Didymograptus  filiformis  Tullberg 

Plate  14,  figures  8-14 

Didy  mograptus  filif  or  mi  s  Tullberg.  Geol.  Foren.  Stockh.  Forh.  1880.  5:42, 
pl.2,  fig.  8-11 

Didymograptus  filiformis  Lapworth.  Ann.  and  Mag.  Nat.  Hist.  ser.  5.  1880. 
6:20 

Didymograptus  filiformis  Brogger.  Die  sil.  Etagen  2  and  3.  1882.  p.39 

Didymograptus  filiformis  Tullberg.  Sver.  Geol.  Und.  1882.  Afh.  och 
upps.  ser.C,  no.  50.  p.22 

Didymograptus  filiformis  Tornquist.  Lunds  Univ.  Arsskrift,  Bd  37,  Af  2. 
nr.  5.  1901.  pl.3,  fig.6-9 

Didymograptus  cf.  filiformis  Elies  &  Wood.  Monogr.  Brit.  Grapt.  pt  1. 
Pal.  Soc.  1901.  p.32,  fig.20 

Didymograptus  filiformis  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t. 
1902.  p.556 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


*>87 


There  occur  in  the  uppermost  part  of  graptolite  bed  2,  belonging  to  the 
Tetragraptus  zone,  very  minute  and  delicate  rhabdosomes  of  a  type  of  the 
declined  group  of  Didymograptus,  which  is  sufficiently  close  in  its  specific 
characters  to  a  species  described  by  Tnllberg  to  warrant  identification  with  it. 

Description.  The  sicula  is  small  (1  mm)  and  narrow.  The  first  and 
second  thecae  branch  out  at  different  distances  from  the  apex  of  the  sicula. 
The  rhabdosome  is  hence  distinctly  unsymmetric  regarding  the  origin  of  the 
branches.  The  latter  are  rather  short,  if  complete  and  of  uniform  width  (not 
exceeding  .25  mm).  The  largest  branch  measures  only  3.2  mm  in  length. 
The  angle  of  divergence  between  the  two  branches  is  about  60°  to  80° ;  in 
one  specimen  110°,  probably  by  oblique  compression.  The  thecae  are  very 
slender,  tubular,  hardly  widening,  numbering  8  in  10  mm,  inclined  at  only 
10°  to  15°  and  overlapping  not  more  than  one  quarter  of  their  length.  The 
outer  walls  and  the  apertural  margins  are  straight ;  and  the  angle  which 
the  latter  form  with  the  axis  of  the  branch  is  90°  or  more. 

These  characters,  which  are  constant  in  about  half  a  dozen  specimens, 
differ  slightly  from  the  original  description  of  Tnllberg,  who  observed  an 
inclination  of  the  thecae  of  about  30°.  But  Tullberg’s  figures  show  an  angle 
of  inclination  not  larger  than  the  one  observed  in  the  Deep  kill  specimens,  and 
the  English  specimens  furnished  also  a  smaller  angle. 

Position  and  localities.  It  has  been  collected  in  the  uppermost  part  of 
graptolite  bed  2  (Tetragraptus  zone),  associated  with  the  sicula  of  all  the 
other  species,  with  which  it  probably  settled  at  the  same  time  on  account  of 
its  similar  weight  and  size.  A  few  specimens  were  also  observed  in  the  beds 
with  D  i  p  1  o  g  r  a  p  t  u  s  dentatus  at  Mt  Moreno  near  Hudson  N.  Y.  The 
range  of  this  species  is  hence  considerable.  Tnllberg  obtained  the  type  of 
the  species  from  the  lower  Graptolite  shales  of  Iviviks-Esperod  in  Scania,  and 
cites  it  later  (1882)  as  a  form  of  the  Tetragraptus  zone  of  Scania.  Tornquist 
found  it  at  Mossebo  in  Westrogothia ;  and  Brogger  in  Etage  3b  (Phyllograptus- 
schiefer)  at  Ivrekling  in  Norway.  Elies  and  Wood  record  that  their  material 
has  been  collected  in  the  Arenig  rocks  of  Bennane  Head  near  Ballantrae, 
Scotland. 


688 


NEW  YORK  STATE  MUSEUM 


Didymograptus  tornquisti  sp.  nov. 

Plate  13,  figures  6,  7 

Description.  Primary  disk  unknown ;  nema  present.  Sicula  small  (1 . 2 
mm).  The  point  of  origin  of  the  first  theca  has  not  been  distinctly  observed. 
The  branches  diverge  near  the  apertural  end  of  the  sicnla,  are  nearly  horizontal, 
gently  curved,  attaining  their  full  width  (1.1mm)  near  the  proximal  part 
and  maintaining  it.  Thecae  numbering  8  in  10  mm,  inclined  at  an  angle  of 
about  20°,  three  times  as  long  as  wide,  in  contact  about  one  third  of  their 
length.  Outer  and  apertural  margins  straight,  the  latter  normal  on  direction 
of  axis  of  theca. 

Position  and  locality.  In  graptolite  bed  3  (zone  of  D  .  b  i  f  i  d  u  s)  asso¬ 
ciated  with  Goniograptus  geometricus,  Tetragraptus  pen- 
d  e  u  s,  I) .  b  i  f  i  d  u  s  and  I)  .  s  i  m  i  1  i  s . 

Remarks.  Only  one  specimen  of  this  species  has  been  observed.  Its 
principal  characters,  viz  the  loose  arrangement  and  low  inclination  of  the 
thecae  and  the  small  amount  of  overlap,  distinguish  it  from  other  forms 
except  I).  af  finis  Nidi.,  which  however  has  much  narrower  branches 
and  a  shorter  sicula.  From  the  similar  I).  nicholsoni  var.  planus, 
which  occurs  in  the  underlying  bed,  it  differs  by  the  smaller  number  of 
thecae  in  a  unit  length. 

Didymograptus  spinosus  sp.  nov. 

Plate  14,  figures  30-32 

Description.  Primary  disk  and  nema  not  observed.  Sicula  small  and 
little  conspicuous  (.9  mm).  First  thecae  diverging  suborallv.  Branches 
moderately  deflexed,  their  angle  of  divergence  about  120°;  very  thin  at  the 
beginning  (not  .8  mm  wide),  but  widening  rather  rapidly  within  10  mm  to  1 
mm.  Mature  length  and  width  of  branches  unknown  ;  the  longest  branch 
observed  attains  a  length  of  16  mm.  Thecae  numbering  12  in  10  mm  ;  nar- 
row,  four  times  as  long  as  wide  in  the  proximal  and  three  times  as  long  as 
wide  in  the  more  distal  parts  of  the  rhabdosome ;  inclined  at  20p  ;  in  contact 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


089 


Fig.  84  Didymograptus  spinosus 
sp.  cov.  Proximal  portion  of  branch.  Asli- 
hill  quarry  at  Mount  Moreno.  x4.5 


for  but  one  third  of  their  length  in  mature  parts  of  rhabdosome.  Outer 
margins  concave,  apertural  margins  straight,  normal  on  axis  of  theca ;  one 
half  the  width  of  branch ;  provided  with  long,  straight  spines,  which 
have  a  direction  perpendicular  to  the  axis  of 
the  branch.  The  dorsal  wall  of  the  branches 
also  provided  with  perpendicular  spines, 
which  alternate  with  the  apertural  ones. 

Position  and  locality.  Rare  in  the 
shales  with  Diplograptus  dentatus  at  Mt  Moreno. 

Remarks.  This  species  is  at  once  distin¬ 
guished  from  all  other  forms  of  Didymograptus 
known  to  me,  by  its  double  row  of  spines.  There 
has  however  been  described  a  species  of  Tetra- 
graptus  (T .  acanthonotus  Gurley,  1890. 
p.65),  from  the  Beekmantown  shales  at  Point 
Levis,  which  exhibits  the  same  spinous  dorsal  margin  as  the  species  in  hand, 
and  which  may  indicate  the  line  of  descent  of  this  Didymograptus  fp.558]. 


Fig.  85  Didymograptus  spin¬ 
osus  sp.  nov.  Portion  of  distal  part 
of  branch.  Ashhill  quarry  at  Mount 
Moreno.  x4 


Didymograptus  bifidus  Hall  sp. 

Plate  15,  figures  1-3 

Graptolith  us  bi  f  idus  Hall.  Canadian  Organic  Remains,  decade  2.  1865.  p.73, 

pl.l,  fig.  16-1 8  ;  pi. 3,  fig.9,  10 

Didymograptus  bifidus  Nicholson.  Quar.  Jour.  Geol.  Soc.  1868.  24:136 

Didymograptus  bifidus  Nicholson.  Ann.  and  Mag.  Nat.  Hist.  ser.  4.  1870. 

5:346,  fig. 7 

Didymograptus  bifidus  Hopkinson  &  Lapworth.  Quar.  Jour.  Geol.  Soc.  1875. 
31:646,  pi. 33,  fig.8a-e 

Didymograptus  b  i  f  i  d  u  s  (?)  Brogger.  Die  sil.  Etagen  2  and  3,  etc.  1882.  p.41 

Didymograptus  bifidus  Herrmann.  Geol.  Mag.  ser.  3.  1886.  3: 1 5 

Didy  m ogra pt  us  b  i  f  i  d  u  s  Ami.  Geol.  Sur.  Can.  Rep’t,  ser.  2.  1889.  v.3,  pt2, 

p.H6k 

Did  ymograptus  bifidus  Barrois.  Ann.  de  la  Soc.  Geol.  du  Nord.  1S92.  20:92 

Didymograptus  bifidus  Gurley.  Jour.  Geol.  1896.  4:295 


NEW  YORK  STATE  MUSEUM 


690 

Didymograptus  b  i  f  i  d  u  s  Elies.  Quar.  Jour.  Geol.  Soc.  1898.  54:511 

Didymograptus  b  i  f  i  d  u  s  Elies  &  W  ood.  Monogr.  Brit.  Grapt.  pt  1 .  Pal.  Soc. 
vol.  for  1901.  p.42,  fig.  26a  and  b 

Didymograptus  bifidus  Ruedemann.  N.  Y.  State  Paleoutol.  An.  Rep’t.  1902. 
p.566,  567 

Description.  Nema  and  primary  disk  not  observed.  Sicula  long  and 
slender,  about  2  mm  long.  Branches  dependent,  rounded  at  their  base,  then 


straight;  angle  of  divergence  of  first  thecae  90°  to  100°, 
that  of  branches  mostly  varying  between  20°  and  25°; 
the  branches  attaining  a  length  of  26  mm,  expanding 
gradually  to  a  maximal  width  of  2.4  mm  near  the  distal 
growing  ends,  the  latter  showing  a  rapid  contraction. 
Thecae  closely  arranged,  numbering  13  to  15  in  10  mm, 
inclined  at  an  angle  of  45°  in  the  mature  and  of  about 
30°  in  the  proximal  parts ;  two  to  three  times  as 
long  as  wide;  in  contact  for  one  half  of  their  length 
in  the  proximal  and  three  fourths  in  the  mature  parts. 
Apertural  margin  slightly  concave,  forming  an  angle  of 
135°  with  axis  of  branch. 


Fig.  86  Didymograp¬ 
tus  bifidus  H  all  sp.  Por¬ 
tions  of  rhubdosomes  en¬ 
larged  to  show  the  form  of 
the  thecae.  Deep  kill.  x5.25 


Position  and  localities.  In  the  Deep  kill  section  common,  but  restricted 
to  graptolite  beds  3  to  5,  which  represent  the  zone  with  P  h  y  1 1  o  g  r  a  p  t  u  s 
anna  and  D.  bifidus.  Hall  records  it  from  Point  Levis  and  from  a 
point  3  miles  above  the  river  St  Anne;  Gurley  lists  it  [1896]  as  a  fossil  of 
the  Phyllograptus  anna  zone  (St  Anne  zone),  and  also  as  occurring 
in  the  Upper  Levis  zone  (zone  with  Dip  log  rapt  us  den  tat  us,  etc.), 
from  which  it  is  absent  at  the  Deep  kill.  He  reports  it  further  from  Nevada 
\ibid.  p.304].  According  to  Ami  the  species  occurs  in  various  localities  in 
the  province  of  Quebec  [1889,  p,116k].  In  Great  Britain  this  species  is, 
according  to  Lapworth,  Elies  and  Wood,  “more  common  than  any  other 
member  of  the  dependent  series ;  it  occurs  in  great  numbers  at  one  particular 
horizon,  namely,  in  the  Upper  Arenig  beds  below  the  zone  of  D .  m  u  rc  li  i  - 
soni”.  It  is  cited  there  from  various  localities  in  Ireland,  Scotland,  Eng- 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


691 


laud  (Lake  district  and  Shropshire)  and  Wales.  Brogger  identified  a  form 
of  the  middle  part  of  the  Phyllograptus  shale  of  the  neighborhood  of  Christi¬ 
ania,  with  some  doubt,  with  D  .  b  i  f  i  d  11  s  ;  and  Herrmann  cites  this  as  a 
somewhat  divergent  form  from  Norway.  In  Scania  (Sweden)  it  occurs 
in  the  Phyllograptus  typus  zone,  associated  with  the  same  fauuule  as  in 
America.  In  Bohemia  it  is  found,  according  to  Perner, 
in  D  1  r,  associated  with  a  great  number  of  other 
dependent  forms.  Barrois  reports  it  as  a  common 
fossil  in  the  schists  with  Bellerophon  oehlerti 
at  Boutoury  near  Cabrieres,  in  the  Languedoc.  The 
species  has  not  yet,  to  my  knowledge,  been  found  in 
Australia,  nor  have  the  other  dependent  forms  been  . 
announced  from  there;  and  it  is  therefore  probable 
that  the  zones  characterized  by  these  forms  have  not 
yet  been  met  with.  It  can  be  inferred  from  its 
general  distribution  that  it,  while  characteristic  and 
best  developed  in  the  zone  which  we  have  named 
after  it,  also  extends  into  the  next  higher  zone  in 
various  regions. 

Remarhs.  This  widely  distributed  species  is  the 
type  around  which  group  themselves  the  dependent  species  of  Didymograptus, 
most  of  which  it  precedes.  It  has  been  carefully  described  by  several  writers, 
lastly  by  the  monographers  of  the  British  graptolites.  The  latter  observed  that 
two  groups  or  types  of  forms  could  be  recognized  by  the  angle  of  divergence, 
that  both,  however,  are  connected  by  a  long  series  of  intermediate  forms.  We 
have  noticed  only  one  of  these  groups,  i.  e.,  the  one  with  a  small  angle  of 
divergence.  This  is  also  the  more  common  form  in  Great  Britain. 

One  of  our  specimens  [text  fig.87]  in  which  the  common  canal  and  the 
first  theca  were  pyritized,  shows  that  the  latter  originated  about  midway 
between  the  apex  and  aperture  of  the  sicula,  grew  a  short  distance  along  the 
sicula  and  then  turned  to  one  side.  The  second  theca  appears  to  originate  at 
or  near  the  geniculation  of  the  first  theca. 


Fig.  87  Didymograptus 
bifid  us  Hall  sp.  Shows  the 
“pustules,”  the  common  canal 
and  the  thickened  apertures. 
Deep  kill,  x  7 


NEW  YORK  STATE  MUSEUM 


692 

The  same  specimen  throws  also  some  light  on  a  peculiar  feature  which  is 
most  noticeable  in  I) .  bifid  u  s,  namely  the  presence  of  small  pustules  at  the 
bases  of  the  thecal  walls.  These  were  also  noticed  by  Hall.1  They  are  not 
always  present;  hence  an  accidental  feature.  When  present  they  are  situated 
with  great  regularity  at  the  place  mentioned.  This  fact  and  their  composition 
of  iron  pyrite  indicate  that  they  originate  by  crystallization  of  pyrite  in  the 
basal  rings,  which,  as  Perner’s  sections  of  specimens  of  Monograptus  \Joc.  cit. 
pl.l ,  his  renjiements  pi  rif or  mes  a  Vextremite  des  ouvertures  internes]  show,  were 
formed  by  the  pyriform  swelling  of  the  interior  ends  of  the  thecal  walls.  This 
ring  held  open,  while  the  perisarc  was  being  compressed,  a  small,  vacant  space 
sufficiently  long  for  the  commencement  of  the  formation  of  the  pyrite  nodules. 


Didymograptus  nanus  Lapworth 

Plate  15,  figures  4,  5 

Didymograpsus  geminus  Nicholson.  Quar.  Jour.  Geol.  Soc.  1868.  24:134, 

pl.5,  tig. 8,  9 

Didymograpsus  geminus  Nicholson  (pars).  Ann.  and  Mag.  Nat.  Hist.  ser.  4. 
1870.  5:346,  fig.6b 

Didymograptus  in  dent  us  var.  nanus  Lapworth.  Quar,  Jour.  Geol.  Soc.  1875. 
31:647,  pi. 33,  fig.7d  ;  pi. 35,  fig.4a-c 

Didymograptus  in  dent  us  var.  nanus  Elies.  Quar.  Jour.  Geol.  Soc.  1898. 
54:511 

Didymograptus  nanus  Elies  &  Wood.  Monogr.  Brit.  Grapt.  pt  1.  Pal.  Soc.  vol. 
for  1901.  p.47,  pi. 4,  tig.Sa-h 

Description.  Nema  and  primary  disk  not  observed.  Sicula  slender,  full 
length  not  observed.  Branches  attaining  a  length  of  22  mm  or  more,  slender, 
of  uniform  width  (1 . 3  mm),  angle  of  divergence  approaching  at  first  90°  but 
soon  becoming  about  12°  or  less.  Thecae  numbering  10  to  12  in  10  mm, 
inclined  at  30°,  rather  long  and  narrow  (ratio  of  length  to  width  3:1),  in  con¬ 
tact  for  one  half  of  their  length  in  the  mature  portion  of  the  branch.  Aper- 

1  See  his  figures,  pl.l,  fig.18  and  pi. 3,  %.10.  In  the  explanation  of  the  latter  figure 
they  are  specially  mentioned. 


GRAPTOLITES  OF  NEW  YORK,  FART  1 


693 


tural  margin  normal  on  the  axis  of  theca  (forming  an  angle  of  150°  with  axis 
of  branch). 

Position  and  localities.  A  single  surface  in  the  quarry  beds  (graptolite 
bed  5,  belonging  to  the  zone  with  1) .  bifidus)  was  found  to  contain  this 
species  in  numerous  specimens.  The  species  has  not  been  reported  from 
Canada.  In  Great  Britain  it  occurs  in  the  Upper  Arenig  of  the  St  David’s 
and  Lake  districts  (Middle  and  Upper  Skiddaw 
slates),  in  association  with  D.  bifidus  and 
Diplograptus  dentatus. 

Remarks.  This  form  was  originally  described  kfiUxls"  Portion  “branch.  Deep 
by  Lapworth  as  a  dwarf  variety  of  D  .  i  n  den¬ 
tils  Hall  (rede  dentatus;  see  Freeh,  Lethaea  palaeozoica  1:590),  with 
which  it  agrees  in  everything  except  size  and  number  of  thecae  in  a  given 
unit  of  length.  While  it  is  sufficiently  distinct  to  be  recognized  as  a  species, 
its  close  relationship  to  1)  .  dentatus  Hall  is  undubitable. 

Brogger  \loc.  cit.  p.40  |  records  the  occurrence  of  a  variety  of  D  .  denta¬ 
tus  at  Krekling  near  Christiania.  This  may  also  be  a  D  .  nanu s. 

* 

Didymograptus  (Isograptus)  caduceus  Salter  emend.  Ruedemann 

Plate  15,  figures  6,  7 

Did  yrnograpsus  caduceus  Salter  (pars).  Quar.  Jour.  Geol.  Soc.  1853.  9:87, 
fig.  la 

D  i  dy  m  ograps  us  caduceus  Salter  (pars).  Quar.  Jour.  Geol.  Soc.  1863.  19:138, 
p.137,  fig.  13a 

Graptolites  (Didy  mograpsus).  caduceus  McCoy.  Pal.  Geol.  Sur.  Vic¬ 
toria.  Prodr.  Pal.  Victoria,  decade  2.  1874.  p.30,  pi. 20.  fig.3-5a 

Tet  rag  rapt  us  bryonoides  Hall  (D.  caduceus  Salter)  Etheridge  jr. 

Ann.  and  Mag.  Nat.  Hist,  ser.4.  1874.  14:2,  pi. 3,  fig.3,  4 

Did  ymograptus  gibber  ul  us  Nicholson.  Ann.  and  Mag.  Nat.  Hist,  ser.4. 
1875.  16:271,  pl.7,  fig.3,  3a,  3b 

Phyllograptus  stella  Hopkinson.  Quar.  Jour.  Geol.  Soc.  1875.  31:658,  pi. 34, 
fig.  6 

Didymograptus  gibber  ulus  Moberg.  Geol.  Fbren.  Stockh.  Forh.  1891. 
13:221 


694 


NEW  YORK  STATE  MUSEUM 


Isograptus  gibber  ulus  Moberg.  Geol.  Forcn.  Stockh.  Fbrb.  1892.  14:346, 

pl-8,  fig.3-7 

Didytnograptus  gibber  ulus  Holm.  S  ver.  Geol.  Und.  Afh.  oeb  upps.  1 895. 
ser.C,  no.150,  p.18 

Didymograptus  (Isograptus)  gibber  ulus  Romer  &  Freeh.  Lethaea 
palaeozoica.  1897.  1:593,  tig.161 

Did  ymograptus  gibber  ulus  Elies.  Quar.  Jour.  Geol.  Soc.  1898.  54:496 
Isograptus  gibberulus  Tornquist.  Lunds  Unix.  Arsskrift.  1901.  Bd37, 
Afd.2,  p.23,  pi. 3,  fig.16-19 

Didymograptus  gibberulus  Elies  &  Wood.  Monogr.  Brit.  Grapt.'ptl. 
Pal.  Soc.  vol.  for  1901.  p.52 ;  p.53,  fig.33a  aud  b,  pl.2,  fig.9a-9e 

Description.  Primary  disk  not  observed.  Nema  filamentous,  very  thin 
and  long.  Sicula  long  and  slender  (length  about  3 . 2  mm).  Two  branches 
which,  bending  in  opposite  directions  upward  and  slightly  backward,  form  a 
rhabdosome  of  horseshoe  shape ;  the  angle  of  divergence  of  the  branches  vary¬ 
ing,  in  the  material,  between  300°  and  330°.  The  branches  are  short  (greatest 
length  observed  5 . 6  mm) ;  widest  at  their  base  (about  2 . 2  mm)  and  diminish¬ 
ing  in  width  toward  the  distal  ends  to  one  half  their  original  width,  this 
diminution  being  produced  by  a  change  in  the  direction  of  the  thecae  from 
straight  downward  to  obliquely  outward  and  upward.  Thecae  long  (the 
proximal  ones  about  2  mm  long)  numbering  11  to  14  in  10  mm,  slightly  curv¬ 
ing  with  the  convex  side  upward,  inclined  in  their  distal  part  toward  the  axis 
at  an  angle  of  45°,  three  times  as  long  as  wide,  in  contact  throughout.  Aper- 
tural  margin  concave,  mucronate  at  the  lower  end  and  receding  upward. 

Position  and  localities.  At  the  Deep  kill  this  form  has  been  obtained 
only  in  half  a  dozen  specimens  found  on  a  slab  which  was  picked  up  loose 
at  the  outcrop  of  graptolite  horizon  2  (zone  with  D.  bifid  us).  I  have 
not  been  able  to  locate  the  bedding  surface  which  is  covered  with  this  inter¬ 
esting  form,  but,  from  the  lithologic  aspect  of  the  slab,  T  believe  that  it  came 
from  the  eastern  part  of  the  quarry  (graptolite  beds  5),  which  in  some  parts 
is  little  accessible  now.  Numerous  specimens  of  a  much  dwarfed  mutation  of 
this  species  [cited  1902,  p.570,  as  D.  (Isograptus)  gibberulus 
Nic.h.  var.  n  anus  var.  nov.]  were  found  in  graptolite  bed  7  (horizon  with 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


695 


Diplograptus  dentatus).  They  will  be  described  in  addition  to 
this  species. 

In  northern  Europe  this  species  has  been  well  known  for  a  long  time.  In 
England  it  occurs  in  the  Upper  Tetragraptus  beds  of  the  Middle  Skiddaw 
slates,  hence  in  the  equivalent  of  the  horizon  to  which  it  probably  belongs  in 
the  Deep  kill  section.  It  is  also  reported  from  the  same  horizon  in  the  shale 
of  the  St  David’s  district  in  W  ales  (Phyllograptus  s  t  e  1 1  a  Ilopkinson). 
In  Sweden  it  characterizes  a  horizon  of  the  lower 
Graptolite  shale  of  Scania  and  Westrogothia  [Torn- 
quist,  loc.  cit.~\.  Holm  had  isolated  material  from  the 
Vaginatenkalk  of  Oeland.  Freeh  mentions  it  as 
having  been  collected  near  Christiania  by  F.  Roeiner. 

It  is  also  characteristic  of  the  lower  graptolite 
shales  of  Victoria  [McCoy,  Etheridge  jr]  and  New 
Zealand,  Australia  [fide  Freeh].  It  has  not  been 
recorded  from  the  Bohemian  basin. 

Reviarhs.  This  species  of  striking  appearance 
and  taxonomic  importance  has  been  elaborately 
described  by  Moberg,  Elies,  Tornquist  and  Lap- 

worth,  Elies  and  Wood.  Our  material  is  not  sufficient  to  verify  all  the  observa¬ 
tions  of  these  authors,  specially  in  regard  to  the  central  parts  of  the  rhabdosome, 
much  less  to  add  to  their  descriptions.  We  learn  from  these  investigators 
that  the  first  theca  originates  very  near  the  apex  of  the  sicula  and  follows  the 
latter  to  a  point  near  the  aperture  of  the  sicula,  where  it  bends  away  from 
the  latter.  Also  the  second  theca  is  nearly  as  long  as  the  first,  so  that  the 
connecting  canal  must  lie  very  high  up. 

Moberg  proposed  to  make  this  species  the  genotype  of  a  new  genus, 
Isograptus,  on  the  ground  that  in  this  form  the  branches  arise  bilaterally  sym¬ 
metric  from  the  sicula,  and  each  branch  is  not  itself  bilaterally  symmetric, 
while  in  Didymograptus  both  branches  arise  at  somewhat  different  levels  at 
the  sicula,  and  each  branch  is  itself  bilaterally  symmetric.  Holm  has  however 
shown  the  relations  of  branches  and  sicula  to  be  the  same  in  Didymograptus 


Fig.'89  Didymograptus  cad- 
uceus  Salter.  Young- rhabdosome. 
Obverse  view.  Deep  kill.  x4.2 


690 


NEW  YOKE  STATE  MUSEUM 


and  Isograptus,  and  on  this  ground  reunited  tliis  form  with  Didymograptus. 
Lap  worth,  Elies  and  Wood  have  pointed  out  later  [loo.  cit.  p.53]  that  the. 
observation  made  by  Tornquist,  that  “  the  first  stipe  crosses  the  sicula  and 
the  second  stipe  the  first  theca,”  seems  to  indicate  a  deviation  from  the  normal 
Didymograptus  type  of  development,  that  is  to  say,  a  forecast  of  the  type 
characteristic  of  the  Diplograptidae,  and  that  this,  if  substantiated,  might 
afford  grounds  for  the  retention  of  this  form  as  the  type  of  a  subgenus.  But 
it  seems  to  me  that,  without  entering  into  the  details  of  the  initial  parts,  D. 
gi  bb  erulus  differs  in  so  important  characters,  that  it  clearly  constitutes  a 
separate  group,  which,  when  the  polyphyletic  origin  of  the  genus  Didymo- 
graptus  shall  be  established,  and  the  components  of  the  various  series  be  made 
out,  will  find  recognition  by  a  separate  term.  It  represents  the  reclined  group 
of  forms,  in  which  the  branches  grow  straight  upward,  and  the  thecae  are  in 
contact  throughout  their  length. 

Nicholson  has  asserted  that  two  very  different  forms  had  been  thrown 
together  by  Salter  under  the  term  I)  .  caduce  u  s.  He  separated  the  biramous. 
component  as  D.  gib  b  erulus,  at  the  same  time  pointing  out  that  this 
species  can  be  readily  distinguished  from  the  other  component,  the  similar 
preservation  of  Tetragraptus  bigsbyi,  where  but  two  branches  are 
preserved,  by  the  fact  that  in  D.  gibber  ulus  the  rhabdosome  is  widest 
in  its  proximal  part,  while  in  Tetragraptus  bigsbyi  it  is  narrowest 
there  [comp.  pi. 12,  fig.6  and  pl.l  5,  fig.fij.  Nevertheless,  the  two  forms  have 
probably  been  confused  on  more  than  one  occasion,  and  D .  caduce  us  may 
for  this  reason  have  a  still  wider  distribution  than  is  accorded  to  it. 

If  Salter  indeed  comprised  two  forms  under  one  specific  term,  according 
to  present  usage,  the  form  which  he  figured  first  has  still  to  retain  his  name, 
and  the  other  to  be  separated  under  a  new  name.  The  two  forms  now,  which 
are  thought  to  be  united  under  Salter’s  term,  viz  D  .  gibber  ulus  Nicholson 
and  Tetragraptus  bigsbyi  Hall,  bear  indeed  a  superficial  resemblance, 
when  the  latter  is  so  preserved  that  but  two  branches  are  seen.  But,  as 
Nicholson,  and  later  Elies  have  asserted,  they  can  be  readily  distinguished  by 
the  aspect  of  the  proximal  part.  Using  this  criterion,  the  reliability  of  which 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


697 

we  had  occasion  to  verify  in  our  material,  in  regard  to  Salter’s  figures,  in  com¬ 
bination  with  other  characters,  it  must  be  concluded  that  Salter’s  first  two 
drawings  and  his  description  [1853,  p.87]  can  apply  only  to  the  form  later  on 
described  as  D .  gibberulus  by  Nicholson.  Of  the  two  drawings  com- 
prised  in  a  later  publication  [1863,  p.137,  fig.l3a,  13b]  under  this  name,  the 
former  is  surely  the  Didymograptus,  the  latter  represents  probably  a  Tetra- 
graptu  s  b  i  g  s  b  y  i .  This  conclusion  is  supporte  dby  the  fact  that  a  long 
nema  is  noticeable  in  the  first  two  drawings  and  is  also  cited  in  the  original 
description  ;  for,  while  the  species  of  D  .  gibber  ulus  are  notable  for  their 
long  nema,  one  will  not  notice  this  filiform  suspensory  organ  among  hundreds 
of  specimens  of  Tet  rag  rapt  us  b  i  g  s  b  y  i . 

It  is,  hence,  apparent  that  Salter  had  before  him,  at  the  time  of  the 
original  description  of  I)  .  c  a  d  u  c  eus,  the  form  which,  later  on,  was  described 
and  is  generally  known  as  D.  gibberul  us  Nicholson,  a  name  which  has, 
then,  to  give  way  to  Salter’s  older  name.  Salter’s  specimens  were  obtained  by 
Dr  Bigsbyfrom  the  “  Lauzon  Precipice,”  and  came  therefore  from  the  Quebec 
shales.  Hall  had  evidently  no  examples  of  this  species  in  his  material  from 
the  Quebec  shales,  or  he  would  not  have  failed  clearly  to  recognize  the  differ¬ 
ence  between  his  T  e  t  r  a  g  r  a  p  t  u  s  b  i  g  s  b  y  i  and  D  .  caduceus  Salter. 
He  states  in  regard  to  the  former :  “  These  forms  resemble  the  G  r  a  p  t  o  1  i 
thus  caduceus  of  Salter  which  was  obtained  by  Dr  Bigsby  from  ‘  the 
Lauzon  Precipice,’  and  I  have  hesitated  in  regard  to  making  of  them  a 
new  species.”  The  writer  has  found  D.  (gibberulus)  caduceus  in  the 
Deep  kill  shales,  so  that  there  can  be  no  doubt  of  the  presence  of  that  species 
on  this  side  of  the  Atlantic. 

R.  Etheridge  jr  figures  both  forms  here  discussed  as  Tet  rag  rapt  us 
bryonoides,  considering  D .  caduceus  as  a  synonym  of  that  species. 
It  is  clear,  however,  from  his  description,  that  he  was  aware  of  the  constancy 
of  the  differences  of  the  two  forms,  united  by  him  under  that  name,  and  he 
suggests  that  Salter’s  name  might  be  retained  as  a  varietal  designation  for 
such  forms  as  those  shown  by  his  figures  3  and  4,  which  represent  specimens 
of  D .  gibberulus  Nicholson. 


698 


NEW  YORK  STATE  MUSEUM 


There  is,  to  state  this  difficult  and  confused  relation  of  the  various  names 
more  concisely,  no  doubt  in  our  mind  that  D.  caduceus  Salter  should 
have  preference  to  Nicholson’s  later  and  better  known  name,  D.  gibber- 
ulus;  that  Salter’s  name  can  not  be  applied  to  T  e  t  r  a  g  r  a  p  t  u  s  b  i  g  s  b  y  i 
Hall,  which  name  in  its  turn  has  to  yield  to  the  older  name  Tetragraptus 
s  i  m  i  1  i  s  Hall. 

Didymograptus  caduceus  Salter  nanus  mut.  nov. 

Plate  15,  figures  8,  9 

A  small  form,  which  I  had  cited  in  Museum  bulletin  52,  1902,  loc.  tit.  as 
D .  gibberulus  var.  nanus,  but  which  more  correctly  should  be  desig¬ 
nated  as  I),  caduceus  mut.  nanus,  occurs  quite  frequently  in  the  last 
horizon  (graptolite  bed  7,  zone  with  D  ip  1  o  g  r  a  p  t  u  s  dentatus).  it 

differs  from  I) .  caduceus  in  its  constantly  smaller 
size  (the  largest  specimen  observed  having  a  length  of 
but  5  mm),  its  wider  proximal  part  (2.3  to  2.5  mm),  the 
abrupt  narrowing  of  the  branches  [fig.8],  the  smaller 
size  aud  closer  arrangement  of  the  thecae  (14  to  18  in 
10  mm),  the  distal  convergence  of  the  branches  and  the 
spinous  processes  of  the  lower  ends  of  the  apertural 
margins. 

These  characters  clearly  indicate  a  concentration  of 
the  entire  development  of  the  rhabdosomes  into  smaller 
space  and  shorter  time,  denoting  the  paracmic  condition  of  the  mutation. 
This  concentration  finds  its  most  pregnant  expression  in  the  specimens,  of 
which  figure  90  is  an  example.  In  this  the  distal  points  of  the  two  branches 
point  toward  each  other  and  have  approached  so  closely  that  the  further 
gemmation  of  thecae  appears  impossible,  and  a  further  growth  of  the  branches 
will  consist  only  in  the  prolongation  of  the  last  thecae,  which  will  produce 
the  rapidly  tapering  branches  of  figure  8.  The  formation  of  long  spines  is  a 
secondary  character,  acquired  in  this  stage. 


Fig.  90  Didymograp¬ 
tus  caduceus  Salter 
nanus  mut.  nov.  Deep 
kill.  x7 


GRAPTOLITES  OF  NEW  YORK.  TART  1 


699 


Didymograptus  forcipiformis  sp.  nov. 

Plate  15,  figures  10-13 

Description.  Primary  disk  not  observed.  N ema  filamentous,  extremely 
thin.  Sicula  long  and  slender  (length  about  3 . 6  mm).  Two  branches,  bent  at 
their  bases  to  such  a  degree  that  their  distal  parts,  which  are  straight,  become 
subparallel  (angle  of  divergence  350°  or  more)  ;  they  attain  a  considerable 
length  (24  mm),  are  wide  at  their  bases  (3  mm),  but  taper  rapidly  to  a  width 
of  .6  mm  or  less.  Thecae  long  in  the  basal  part  of  the  branches  (3  mm),  but 
becoming  shorter  in  the  distal  portions,  where  they  are  more  inclined  (45°) ; 
numbering  but  9  to  10  in  10mm,  curved,  about  three 
times  as  long  as  wide,  in  contact  throughout  their  length. 

Apertural  margin  slightly  concave,  lower  part  produced 
into  a  mucro  or  short  spine  in  the  distal  portion  and 
into  long  spines  in  the  long,  proximal  thecae. 

Position  and  locality „  This  species  has  been  observed 
only  in  the  beds  with  Diplograptus  den  tat  us 
at  Mt  Moreno  near  Hudson,  in  one  layer  of  which  it 
occurs  quite  frequently. 

PemarJcs.  D .  forcipiformis  differs  from  I) . 
cad  uce  u  s  Salter,  of  which  it  is  a  late  derivative,  by  the  greater  divergence 
of  the  branches,  by  the  smaller  width  of  the  distal  portion  of  the  branches 
and  their  greater  rate  of  tapering,  the  great  width  of  the  proximal  portion  of 
the  branches,  the  less  close  arrangement  of  the  thecae  and  the  presence  of 
mucros  or  spines  at  the  apertural  margins. 

Elies  and  Wood  state  that  there  occur  among  the  British  forms  of  D. 
gibber ul  us  Nicholson  (=D.  caduceus  nobis')  several  mutations,  in  one 
of  which  “  the  dorsal  walls  of  the  stipes  are  straight  distally,  the  stipes  run¬ 
ning  parallel  to  each  other”.  Our  form  agrees  with  this  mutation  in  the 
general  direction  of  the  branches,  though  the  branches  in  D  .  forcipiformis 
approach  each  other  still  much  more  than  they  do  in  the  examples  figured  by 
Elies.  In  fact,  none  of  the  European  forms  which  I  have  seen  figured  appear 


Fig.91  Didymograptus 
forcipiformis  sp.  nov. 
Middle  portion  of  branch. 
Ashhill  quarry  at  Mount 
Moreno.  x5 


700 


NEW  YORK  STATE  MUSEUM 


to  show  as  closely  approaching  branches  as  the  Mt  Moreno  form.  The  latter 
differs  from  all  these  still  further  by  the  looser  arrangement  of  the  thecae, 
which  are  provided  with  spines. 

While  this  form  does  not  possess  the  general  gerontic  aspect  of  the  form 
designated  in  this  work  as  D.  caduceus  mut.  nanus,  it  appears  as  an 
extreme  development  of  D.  caduceus  by  the  divergence  and  slenderness 
of  the  branches  and  has  the  spinous  apertures  in  common  with  the  paracmic 
mutation  of  D .  caduceus,  just  cited. 


Didymograptus  incertus  sp.  nov. 

Plate  15,  figure  14 

Didymograptus  sp.  nov.  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.570 


Fig.  92  Didymograptus  incertus 
sp.  nov.  Portion  of  branch  of  specimen 
reproduced  on  pl.15,  fig.  14.  Shows  thicken¬ 
ing  of  dorsal  wall.  Deep  kill,  x  7 


Description.  Primary  disk  and  nerna  not  observed.  Sicula  apparently 
rapidly  tapering  (longer  than  1 . 5  mm).  Branches  reclined,  first  horizontally 

(about  2  mm),  then  diverging  at  an  angle  of 
1 10°,  their  width  in  the  proximal  region  about 
1.2  mm,  increasing  to  1.9  mm  and  decreasing 
again  toward  the  distal  ends.  Thecae  number¬ 
ing  8  to  9  in  10  mm,  inclined  at  an  angle  of  40°, 
three  times  as  long  as  wide,  in  contact  for  one 
half  to  two  thirds  of  their  length.  Outer  margin  slightly  convex,  apertural 
margin  concave,  mucronate. 

Position  and  locality.  A  single  specimen  was  found  in  graptolite  bed  7, 
horizon  of  Diplograptus  dentatus;  associated  with  the  latter  species, 
D .  caduceus  mut.  nanus,  etc. 

Remarks.  The  sicula  is  preserved  only  fragmentarily  and  as  an 
impression.  Its  characters,  as  well  as  those  of  the  first  theca  could  therefore 
not  be  made  out  with  sufficient  accuracy. 

This  form  bears  a  superficial  resemblance  to  D.  caduceus  and  could 
be  taken  for  a  representative  of  that  species,  in  which  the  branches  have  be  *:i 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


701 


forced  apart  by  some  accident.  Closer  comparison  shows  however  that  the 
thecae  are  less  closely  arranged  and  free  for  a  greater  portion  of  their  length. 

The  dorsal  part  of  the  common  canal  is  so  strongly  thickened  in  this 
species  that  it  appears  like  a  solid  rod,  or  virgula,  suggesting  in  this  feature, 
as  in  the  general  form,  an  approach  to  Dicellograptus. 

Family  coenograptidae  nom.  nov. 

SIGMAGRAPTUS 1  gdl.  llOV. 

Two  principal  branches,  which  together  form  a  sigmoidally  curved  rhab- 
dosome.  From  these  originate  alternately  on  both  sides,  denticulate  side 
branches  which  do  not  bifurcate  again. 

It  is  evident  that  this  genus  belongs  to  the  coenograptids,  its  closest  rela¬ 
tionship  being  with  Coenograptus  itself,  from  which  it  differs  only  by  the 
arrangement  of  the  branches  on  both  sides  of  the  principal  branches  instead 
of  on  one  side.  It  can  however  be  noticed  on  well  preserved  specimens  of 
Coenograptus  gracilis  that  every  second  side  branch  bends  across 
the  principal  stem  to  the  same  side  as  the  preceding  branch,  so  that  the  origi¬ 
nal  arrangement  of  the  branches  of  Coenograptus  was  probably  the  same  as 
that  in  Sigmagraptus.  As  Coenograptus  retains  the  sigmoid  curve  of  the  two 
principal  branches  and  is  a  younger  genus,  it  can  be  safely  concluded  that  it 
is  directly  derived  from  Sigmagraptus.  The  species  of  Sigmagraptus,  here 
described,  has,  as  we  have  shown  before,  |  p.565j  a  Goniograptus  as  ancestor. 

The  genus  Pterograptus  has  the  same  alternating  arrangement  of  the 
branches  as  Coenograptus,  but  they  are  there  distinctly  pendent  and  sugges¬ 
tive  of  a  derivation  from  a  Bryograptus  with  dependent  branches.  In  Pleuro- 
graptus  the  branches  are  given  off  alternately  on  both  sides  as  in  Sigmagraptus 
but  are  provided  again  with  tertiary  branches.  This  structure  could  be  readily 
referred  to  that  of  Sigmagraptus.  The  genus  Amphigraptus,  finally,  ’which 
was  erected  by  Lap  worth  [1873J  for  forms  like  Graptolithus  diver- 
gens  Hall,  from  the  Quebec  shales  of  Levis,  is  said  to  have  the  branches  not 


1  Sigma ,  the  letter  Sigma,  grapho  to  write. 


702 


NEW  YORK  STATE  MUSEUM 


arranged  alternating  but  in  pairs  This  genus  has  not  been  recognized  by 
Roemer  and  Freeh  in  the  Lethaea  palaeozoica,  but  has  been  united  with  Coe- 
nograptus.  But,  if  the  observation  of  the  paired  arrangement  of  the  branches 
is  correct,  the  mode  of  bifurcation  must  be  essentially  different  from  that  in 
Coenograptus,  Pterograptus  etc.  In  fact,  there  is  no  other  graptolite  known 
to  the  writer  in  which  a  paired  arrangement  of  side  branches  occurs. 

All  the  other  genera  of  the  coenograptids  (excluding  Ampkigraptus) 
appear  much  later  than  Sigmagraptus. 

The  stem  or  principal  branch  consists  of  thecae  in  exactly  the  same  man¬ 
ner  as  that  of  Pterograptus  and  Coenograptus,  i.  e.  each  internode  between 
two  side  branches  is  formed  by  one  theca. 

Genotype :  Sigmagraptus  praecursor  sp.  nov. 

Sigmagraptus  praecursor  sp.  nov. 

Plate  5,  figure  13 

Coenograptid  gen.  nov.  et  sp.  nov.  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t. 

1902.  p.566 

The  graceful  slender  branches  of  this  species  occur  quite  often  in  grapto¬ 
lite  bed  3  of  the  Deep  kill  section.  As,  however,  they  are  usually  mingled  in 

an  intricate  manner  with  specimens 
of  Goniograptus  and  other  ramifying 
Fig.  93  sigmagraptus  praecursor  sp.  nov.  species,  it  is  difficult  to  observe  perfect 

organisms.  The  example  figured  was 
found  on  a  slab  unobscured  by  other  graptolites. 

Description.  Rhabdosome  consisting  of  two  principal  stems,  which 
together  form  a  sigmoid  curve.  From  these  originate  in  regular  intervals 
long,  straight,  filiform  side  branches,  only  .  3  mm  wide  and  which  normally 
form  angles  of  90°  with  the  principal  branches.  The  latter  have  been  seen 
to  attain  together  a  length  of  40  mm,  the  side  branches  one  of  20  mm.  The 
sicula  has  not  been  found  sufficiently  well  preserved  for  exact  measurement; 
from  it  branch  two  primary  thecae,  with  a  length  of  1 . 4  mm  each,  which  form 
a  horizontal  central  bar.  The  internodes  between  the  brauches  consist  of  one 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


703 


theca  each  and  have  a  length  of  1.8  mm  each.  The  thecae  are  extremely 
slender,  tubular,  without  any  noticeable  widening  toward  the  aperture,  over 
lapping  about  one  third  of  their  length  ;  diverging  from  the  axis  of  the  branch 
not  more  than  12°;  their  outer  walls  and  apertural  margins  are  straight,  the 
latter  half  as  wide  as  the  branch  and  forming  an  apertural  angle  of  5°.  The 
brachial  thecae  number  8  in  10  mm. 

Position  and  locality.  Graptolite  bed  3  of  the  Deep  kill  section,  belong¬ 
ing  to  the  zone  with  Didymograptus  b  i  f  i  d  u  s  and  Phyllograptus 
anna. 

\ 

Remarks.  The  principal  stems  are  found  to  be  composed  of  thecae  formed 
by  the  successive  bifurcations.  As  alternately  the  right  and  the  left  of  the 
two  diverging  thecae  become  internodes  of  the  stem,  the  latter  shows  still  an 
obscure  zigzag  line,  suggestive  of  an  origin  identical  with  that  of  the  principal 
stems  of  Goniograptus.  While  the  mode  of  branching  of  Sigmagraptus,  like 
that  of  the  younger  coenograptids,  has  to  be  designated  as  monopodial  or 
lateral,  one  of  the  branches  always  essentially  retaining  the  direction  of  the 
mother  theca,  still  the  faint  presence  of  a  zigzag  curve  in  the  principal  stem 
indicates  that  the  mode  of  branching  in  this  form  is  also  originally  dichotomous 
in  character,  and  differs  only  from  that  of  Goniograptus  in  the  greater  degree 
of  the  divergence  of  the  thecae,  from  which  the  denticulate  branches  originate, 
and  a  corresponding  lesser  degree  of  divergence  of  the  stolonal  or  stem  thecae. 

No  similar  form,  'which  would  invite  comparison,  is  known  to  the  writer. 
Coenograptus  gracilis,  while  easily  distinguished  by  the  arrangement 
of  the  branches,  has  very  similar  thecae  and  branches. 


Family  phyllograptidae  Lap  worth 
PHYLLOGRAPTUS  Hall.  1857 

This  genus  was  first  defined  by  Hall  in  the  report  on  Canadian  graptolites 
[1857,  p.31]  and  more  fully  described  in  his  Graptolites  of  the  Quebec  Group 
[  1865,  p.118  ].  Hall  recognized  thus  early  the  essential  facts  of  its  structure, 
viz  the  composition  of  the  rhabdosome  of  four  branches,  which  have  coalesced 


704 


NEW  YORK  STATE  MUSEUM 


with  their  dorsal  sides,  but  he  considered  the  structure  as  analogous  with  that 
of  Diplograptus,  assuming  that  the  fronds  of  the  latter  were  formed  by  the 
coalescence  of  two  monoprionidian  branches,  and  as  a  corollary  lie  inferred  the 
presence  of  a  solid  axis  or  virgula  as  in  Diplograptus.  The  rhabdosomes  of 


Fig.  94  Phy  1 1  og rap tus  angustifolius  Hall,  a  View  of  a  rhabdosome.  etched  out  of 
limestone.  Seen  from  t lie  reverse  (antisieular)  side.  x4  h  Sieular  end  of  rhabdosome,  seen  from 
the  obverse  (sieular)  side.  x6  <•  Rhabdosome  seen  from  the  similar  end.  Shows  the  apertures  of 
the  sicula  (in  the  centeri,  of  the  tirst  two  thecae  (Hanking  the  sicula),  and  of  the  earliest  portions 
of  the  branches.  .\6.  rl  Transverse  section  through  a  rhabdosome,  showing  the  central  coeno- 
sarcal  canal  and  its  four  longitudinal  septa.  x6  (Copies  from  Holm) 


Diplograptus  have  now  however  been  demonstrated  to  be  not  the  result  of  the 
coalescence  of  two  branches,  but  of  the  budding  of  thecae  of  one  series  alter¬ 
nately  on  opposite  sides.  It  is,  hence,  evident  that  the  two  genera  are  of 
entirely  different  structure.  Subsequent  observers,  as  Lapworth,  Tullberg 
and  Tornquist,  have  all  corroborated  Hall’s  conception  of  Phvllograptus,  and 
Tullberg  recognized  the  close  relationship  between  Tetragraptus  and  Phyllo- 
graptus. 


GRAPTOLITES  OF  NEW  YORK.  TART  1 


705 


This  relationship  has  now  been  fully  demonstrated  by  Holm’s  funda¬ 
mental  work  on  the  genera  Didymograptus,  Tetragraptus  and  Phyllograptus 
[1895,  p.27].  Holm  isolated  specimens  of  P.  angustifolius  preserved 
plastically  in  the  Yaginatenkalk  of  Oeland  and  by  means  of  thin  sections 
proved  that  the  gemmation  of  the  first  thecae  and  the  formation  of  the  four 
branches  of  the  rhabdosome  take  place  in  exactly  the  same  manner  as  in  Tetra¬ 
graptus  [text,  p.476  |.  The  sicula  is  embedded  at  the  distal  end  of  the  rhab¬ 
dosome,  the  four  branches  growing  backward  from  the  initial  point  toward  the 
point  of  fixation,  as  in  T  e  t  r  a  g  r  a  p  t  u  s  (b  i  g  s  b  y  i)  s  i  m  i  1  i  s  .  Between 
this  species  and  P.  angustifolius  there  exists  the  closest  agreement, 
both  in  internal  and  external  structure.  In  Phyllograptus,  however,  the  four 
branches  have  coalesced,  so  that  the  four  coenosareal  canals  form  a  quadri¬ 
partite  internal  tube,  and  the  four  independent  periderm  walls  of  Tetra¬ 
graptus  similis  have  united  into  “a  single,  cruciform,  four  winged, 
longitudinal  septum”  [section,  fig.9-b/].  The  longtitudinal  partitions  of  the 
central  tube  consist,  hence,  of  a  single  layer. 

The  material  from  the  Deep  kill  consists  largely  of  flattened  specimens  in 
slate.  Among  them  there  occur  finely  macerated  examples  in  a  layer  of  the 
quarry  beds  [pi. 15,  fig.33],  which  show  the  interthecal  walls  in  excellent 
preservation.  In  a  layer  of  graptolite  bed  2  the  specimens  of  P .  ilicifolius 
were  largely  preserved  plastically  by  having  become  the  centers  of  pyrite 
nodules.  Sections  through  these  have  permitted  us  to  investigate  the  internal 
structure  of  that  species. 

Hall  suggested  that  the  fronds  or  rhabdosomes  of  Phyllograptus  may 
have  been  attached  in  groups  to  some  other  support,  a  suggestion  which 
was  based  on  their  arrangement  on  a  slab  figured  on  plate  15  (figure  10)  of 
his  work.  This  arrangement  is,  however,  accidental,  as  the  writer  had 
occasion  to  satisfy  himself,  and,  as  is  indicated  by  the  irregular  distribution 
of  the  antisicular  extremities  of  the  rhabdosomes.  The  mode  of  occurrence 
of  Phyllograptus  would  rather  suggest  that  the  rhabdosomes  as  found  now 
constituted  the  entire  colony,  only  the  organ  of  suspension  having  been  lost 
or  failed  of  preservation. 


TOli 


NEW  YORK  STATE  MUSEUM 


Holm  states  that  no  virgula  has  been  observed  [1895,  p.489];  while 
Elies  reports  [1896,  p.494]  having  seen  one  in  a  specimen  of  P.  anna 
passing  from  the  apical  end  of  the  sicula  the  full  length  of  the  rhabdo- 
some.  The  homology  of  the  structure  Avith  that  of  Tetragraptus 
s  i  m  i  1  i  s  argues  certainly  for  the,  at  least  temporary,  suspension  of  the  sicula 
from  a  primary  disk  by  means  of  a  neraa.  Corresponding  to  the  growth  of 
the  four  branches  in  a  proximal  (or  backward)  direction  this  nema  must  have 
become  inclosed  into  the  rhabdosome,  analogous  as  in  Diplograptus.  If  it 
then  is  sometimes  absent,  as  Holm’s  observation  in  P.  angustifolius 
Avould  tend  to  shoAv,  it  must  have  been  received  so  intimately  into  one  of 
the  peridermal  walls,  that  it  is  no  longer  distinguishable  as  a  separate  body, 
which  is  the  more  possible,  as  it  is  anyAvay  an  extremely  slender  and  delicate 
thread  in  most  Dichograptidae. 

It  is,  however,  a  peculiar  fact  that  among  the  very  great  number  of 
Avell  preserved  specimens  found  in  the  New  York  shales  not  a  single  one  has 
been  observed  with  any  trace  of  a  nema  protruding  from  the  antisicular 
end  of  the  rhabdosome.  Nor  do  I  find  any  suggestion  in  either  the 
descriptions  or  the  figures  of  other  material  indicating  that  such  an  organ 
has  e\rer  been  noticed.  Yet  it  is  necessary  to  postulate  the  suspension  of  the 
colony  from  the  ascending  growth  directions  of  the  branches  as  Avell  as  of 
the  thecae.  The  appendages,  Avhich  Avere  observed  by  Hall,  in  P.  typus, 
and  termed  “radicles”  are  sicular  spines  and,  therefore,  found  at  the  oppo¬ 
site  free  end  of  the  rhabdosome.  While  we  have  not  noticed  them  in  our 
material  of  P .  typus,  they  were  found  to  be  Avell  developed  in  P .  anna 
[pi. 15,  fig.23]  and  in  P .  ilicifolins. 

The  phylogeny  of  the  group  has  been  touched  in  the  introduction 
[p.563], 

Phyllograptus  ilicifolius  Hall 

Plate  15,  figures  15-22 

Phyllograptus  ilicifolius  Hall.  Canadian  Organic  Remains,  decade  2. 

1865.  p.  121,  pi. 16,  fig.1-10 

Cf.  Phyllograptus  ilicifolius  var.  g  r  a  n  d  i  s  Elies.  Quar.  Jour.  Geol.  Soc. 

1898.  54:493 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


TOT 


Cf.  Phyllograptus  ilicifolius  var.  g  r  a  n  d  i  s  Elies  &  Wood.  Monogr.  Brit. 

Grapt.  pt  1.  Pal.  Soc.  vol.  for  1902.  p.102,  pl.13,  fig.8 
Pliyllograptus  ilicifolius  Ruederaaun.  N.  Y.  State  Paleontol.  An.  Rep’t. 

1902.  p.554,  556. 

Description.  Rhabdosome  consisting  of  four  branches,  mostly  broadly 
semioval,  which  are  joined  at  right  angles  by  their  longitudinal  axes  so  as 
to  form  two  intersecting  ovals.  The  rhabdosome  attains  a  maximum  length 
of  19.5  mm  and  a  width  of  11.3  mm;  the  dimensions  of  average  specimens 
are  however  smaller  by  one  fourth.  Character  and  length  of  sicula  not  ascer¬ 
tained  ;  similar  end  provided  with  a  rather  long  (8  mm) 
spine.  The  thecae  are  in  contact  throughout  their 
length,  number,  in  the  majority  of  the  specimens,  12  in 
10  mm,  with  variations  to  11  and  13;  they  are  much 
curved;  first  ascending  near  the  similar  end,  then 
curving  outward  and  downward,  this  curvature  decreas¬ 
ing  gradually  toward  the  center, 

,  •.  ■.  ijti.i  al  portion  showing  thecal 

where  the  thecae  are  but  slightly  apertures  and  mucros.  Deep 

®  ^  kill.  x8 

bent  and  placed  approximately 

horizontally;  toward  the  antisicular  portion  of  the 
rhabdosome  they  become  more  and  more  directed 
upward,  till  at  the  antisicular  end  they  run  subparallel 
to  the  axis  of  the  rhabdosome.  The  apertures  are 
slightly  concave ;  oblique  in  the  similar  portion  and 
vertical  on  the  axis  of  the  thecae  in  the  central  and 
antisicular  portions ;  their  lower  margins  are  extended 
into  short  concave  tongues  [fig. 9 5]  which  in  the 
laterally  compressed  rhabdosomes  appear  as  slender 

Position  and  localities.  Very  common  and  typical  in  graptolite  bed  2 
(Tetragraptus  horizon) ;  rare  in  graptolite  bed  1,  belonging  to  the  same 
horizon  and  not  observed  in  typical  specimens  in  the  highest  horizon  of 
the  Deep  kill  section.  In  the  beds  with  Didymograptus  bifidus 


Fig.  96  Phyllograptus 
i  licif  olius  Hall.  Enlarge¬ 
ment  of  a  pai't  of  a  rhabdo¬ 
some.  Deep  kill.  x6 


mucros  [hg.96j. 


70S 


NEW  YORK  STATE  MUSEUM 


it  occurs  still  sparingly.  Hall’s  types  came  from  the  first  mentioned  horizon. 
Elies  and  Wood  describe  from  the  Middle  Skiddaw  slates  a  varietal  form 
as  P  .  ilicifolius  var.  g  r  a  n  d  i  s ,  which  differs  from  the  typical 
material  only  by  its  much  greater  size.  Some  of  the  largest  specimens  from 
the  Deep  kill  approach  this  major  variety  in  form,  but  are  connected  by  inter¬ 
vening  sizes  with  the  normal  specimens. 

Remarks.  Hall  described  this  form  as  broadly  oval  or  ovate.  While 
the  majority  of  the  numerous  specimens  in  the  Deep  kill  correspond  to  this 
description,  there  are  on  one  hand  extremely  broad  forms  and  on  the 
other  extremely  long  and  narrow  ones  [fig.lG,  19],  transitional  forms  leading 
over  to  both  extremes. 

It  is,  hence,  evident  that  in  this  bed  at  least  P.  ilicifolius  is 
almost  as  variable  as  P.  typus  in  a  later  horizon.  The  thecae  in  the 
middle  part  may  approach  the  direction  of  those  of  P .  angustifolius, 
but  P .  ilicifolius  is  always  readily  distinguished  from  that  species  by 
the  direction  of  the  thecae  in  the  sicular  and  antisicular  portions. 

This  form  is  also  easily  distinguished  from  P  .  typus,  which  follows 
it  in  the  Deep  kill  section,  by  its  more  closely  arranged  thecae  and  the 
different  character  of  the  apertures,  which  here,  in  the  compressed  form, 
are  adorned  with  long,  narrow  mucros. 


Phyllograptus  typus  Hall 

Plate  15.  figures  35-37 

Phyllograptus  typus  Ilall.  Geol.  Sur.  Can.  Rep’t  for  1 857.  1858.  p.137 
Phyllograptus  typus  Billings.  Geol.  Sur.  Can.  Pal.  Foss.  1865.  1:366,375 

Phyllograptus  typus  Hall.  Geol.  Sur.  Can.  decade  2.  1865.  p.119,  pi.  15, 

fig. 1-12 

O 

Phyllograptus  typus  Tdrnquist.  Lunds  Univ.  Arsskrift.  T.  1,  pt  iii,  1865. 
p.16,  pl.l,  fig.9,10 

Phyllograptus  typus  Nicholson.  Quar.  Jour.  Geol.  Soc.  1868.  24:133,  pl.5, 
fig.  16 

Phyllograptus  folium  (His.  sp.)  var.  typus  (Hall)  McCoy.  Geol.  Sur. 
Victoria.  Prodr.  Pal.  Victoria  decade  1.  1874.  p.7f,  pl.l,  fig.1-4 


Git  A  OTOLITES  OF  NEW  YOKE,  PART  1 


709 


Phyllograptus  typus  Brbgger.  Die  sil.  Etagen  2  and  3.  1882.  p.41 

P  h  y  1 1  og  r  a  p  t  u  s  cf.  typus  Tullberg.  Skanes  Grapt.  in  Sver.  Geol.  Und.  Afli. 
och  npps.  ser.  C,  no.  50.  1882.  p.21 

Phyllograptus  typus  Malaise.  Ann. de la  Soc.  Geol.  de  Belg.  1888.  t.15,  bid. 
p.42 

Phyllograptus  typus  Ami.  Geol.  Sur.  Can.  Rep’t.  1SS9.  v.3,  pt  2,  p.50k  ff 

Phyllograptus  typus  Gurley.  Jour.  Geol.  1896.  4:294 

Phyllograptus  t  y  p  n  s  Roemer  &  Freeh.  Lethaea  palaeozoiea.  1897.  1 :005 

Phyllograptus  typus  Elies.  Quar.  Jour.  Geol.  Sue.  189S.  54:494f 

Phyllograptus  cf.  typus  Elies  &  Wood.  Monogr.  Brit.  Grapt.  pt  1.  Pal. 
Soc.  vol.  for  1902.  p.99,  pi.  13,  fig.5a,b 

Phyllograptus  typus  Ruedemann.  N.  Y.  State  Paleontol.  Ann.  Rep’t.  1902. 
p.566 

This  species,  which,  both  by  the  gigantic  size  and  the  great  variability 
of  its  individuals,  marks  the  acmic  stage  of  development  in  the  short  lived 
genus  Phyllograptus  has  been  fully  described  by  its  author  and  lately  by 
Elies  and  Wood.  From  these  descriptions  and  the  material  in  hand  we 
derive  the  following  enumeration  of  the  distinctive  features  of  the 
species. 

Description.  The  rhabdosome  is  exceedingly  variable  in  relative  length 
and  width,  or  in  outline  generally.  Hall  described  it  as  being  “  elongate 
ovate  or  lanceolate,  broad  oval  or  obovate,”  and  Miss  Files’s  extensive  measure¬ 
ments  demonstrate  that  in  the  Skiddaw  specimens,  the  variations  extend  from 
long  and  narrow  forms,  whose  relative  length  and  width  are  57  and  6.3  mm, 
to  short  and  broad  forms  with  25.4  and  8.7  as  corresponding  figures. 
Our  material  does  not  quite  reach  these  extremes,  but  still  illustrates  well 
the  lack  of  fixation  of  the  outline,  and  specially  the  frequent  occurrence  of 
lanceolate  forms  and  the  tendency  of  the  rhabdosome  to  attain  its  maximal 
width  in  the  sicular  half. 

The  thecae  are  in  contact  throughout  their  length,  number  9  to  10  in 
10  mm,  and  are  curved  in  all  parts  of  the  rhabdosome,  viz  in  the  similar 
portion  slightly  upward,  which  curvature  lessens  toward  the  middle  portion 
and  finally  assumes  an  obliquely  upward  direction  in  the  antisicular  portion. 
The  apertures  are  but  slightly  mucronate. 


710 


NEW  YORK  STATE  MUSEUM 


The  sicula  has  not  been  observed  in  any  of  the  writer’s  specimens,  nor  has 
the  sicular  process,  which  according  to  .Hall  attains  a  length  of  about  \  inch, 
been  noticed. 

Position  and  localities.  In  the  Deep  kill  P  .  t  y  p  u  s  has  been  found 
sparsely,  in  rather  large  specimens  at  the  base  of  graptolite  bed  3 ;  and  in 
great  number,  but  in  smaller  size,  in  the  intercalations  in  the  quarry,  belong 
ing  to  the  same  zone  (zone  with  Didymograptus  bifidus). 

According  to  its  citations  in  the  literature  this  species  could  be  con¬ 
sidered  as  one  of  the  most  widely  distributed ;  it  is,  however  probable 
that  some  of  the  graptolites  which  have  been  identified  with  it  belong 
to  other  species.  So  for  example,  the  monographers  of  the  British  grapto¬ 
lites  have  not  been  able  to  identify  positively  the  material  currently  cited 
in  Great  Britain  as  belonging  to  P.  typus  with  that  Quebec  species. 
And  also  in  Sweden  in  later  time,  the  investigators  have  not  felt  justified 
in  doing  more  than  to  characterize  the  uppermost  zone  of  the  lower  grapto¬ 
lite  shale  as  the  zone  with  P .  cf.  typus  Hall.  Gurley,  further,  refers 
with  doubt  a  form  from  Arkansas  to  this  species. 

Hall’s  types  came  from  the  beds  at  Point  Levis.  As  no  associated 
forms  are  cited,  it  is  uncertain  whether  these  types  were  collected  in  the  lower 
or  upper  Point  Levis  zone.  From  its  associates  in  the  Deep  kill  we  suppose 
that  this  species  belongs  in  the  upper  part  of  the  lower  horizon.  Ami 
lists  it  from  several  localities  near  Point  Levis,  in  association  with  forms 
of  the  Tetragraptus  zone.  Billings  recorded  it  from  the  Cow  head  on 
Newfoundland.  The  specimens  referred  in  Great  Britain  to  the  same 
are  found  in  the  upper  beds  of  the  Middle  Skiddaw  slates  of  the  Lake 
district.  Tornquist  and  Tullberg  identify  forms  in  Scania  with  it  and 
Brogger  mentions  it  as  common  in  the  shales  at  Christiania.  It  also  has 
been  collected  by  Cluysenaar  and  Lecrenier'  at  Huy-Statte  in  Belgium  and 
listed  as  Diplograpsus  folium,  the  identification  having  been  cor¬ 
rected  by  Malaise. 

McCoy  records  it  from  numerous  places  in  Victoria,  Australia. 


GRA PTOLITES  OF  NEW  YORK,  PART  1 


711 


Hemarks.  According  to  Elies  this  species  is  characterized  by  (1)  the 
number  of  thecae  in  a  given  unit  of  length,  (2)  the  form  of  the  aperture, 
which  is  equally  extended  at  its  upper  and  lower  limits.  These  characters 
serve  specially  to  distinguish  the  narrow  variation  of  P .  typus  from 
P .  angustifolius,  which  has  more  closely  arranged  thecae,  and  longer 
apiertural  mucros,  which  are  extensions  only  of  the  lower  part  of  the 

apertures  giving  the  latter  an  oblique  direction.  Also,  the  character  of  the 
curvature  of  the  thecae  and,  specially,  the  direction  of  those  of  the 

antisicular  portion  furnish  a  means  of  distinction  of  P .  typus  from 

P.  angustifolius. 

P.  ilicifolius  exhibits,  in  the  Deep)  kill  section,  a  variability  of 
form  similar  to  that  of  P .  typus.  It  also  possesses  a  similar  character 
of  curvature  of  the  thecae,  but  has  corresponding  to  its  generally  smaller 
size,  more  closely  arranged  thecae,  and,  besides,  longer  and  different]}' 
shaped  apertural  mucros.  P.  typus  and  ilicifolius,  though  not 

mentioned  by  Hall  as  occurring  in  different  associations  are  in  their  principal 
development,  separated  in  the  Deep)  kill  section,  where  P.  ilicifolius 
precedes  P .  typus. 


Phyllograptus  angustifolius  Hall 

Plate  15,  figures  31-34 

Phyllograptus  angustifolius  Hall.  Geol.  Sur.  Can.  Rep’t.  for  1857.  1858. 

p.139 

Phyllograptus  angustifolius  Salter.  Quar.  Jour.  Geol.  Soc.  1863.  19:137, 

fig. 7a,  l) 

Phyllograptus  angustifolius  Hall.  Geol.  Sur.  Can.  decade  2.  1865.  p.125, 

pi. 16,  fig.17-21 

Phyllograptus  angustifolius  Nicholson.  Quar.  Jour.  Geol.  Soc.  1868. 
21:132 

Phyllograptus  angustifolius  Linnarsson.  Sver.  Geol.  Und.  1879.  Afh. 
och  upps.  ser.C,  no.31.  p.5 

Phyllograptus  cf.  angustifolius  Tullberg.  Sver.  Geol.  Und.  1882.  Afh. 
och  upps  ser.C,  no.50.  p.22 


712 


NEW  YORK  STATE  MUSEUM 


Phyllograptus  an  gust  if  oli  us  lirugger.  Die  sil.  Etagen  2  and  3.  1882.  p.41 
Phyllograptus  angustifolius  Ami.  Geol.  Sur.  Can.  Rep’t.  1889. 
v.3,  pt  2,  p.50k  ff 

Phyllograptus  angustifolius  Holm.  Geol.  For.  Fork.  1895.  Band  17, 
heft  3,  p.319,  pi. 3 

Phyllograptus  angustifolius  Wirnan.  Geol.  Inst.  Upsala.  Bui.  4.  1895. 

v.2,  pt  2,  p.39,  pi. 9,  fig.8 

Phyllograptus  angustifolius  Elies.  Qnar.  Jour.  Geol.  Soc.  1898.  54:196 
P  h  y  1 1  o  g  r  a  p  t-u  s  angustifolius  Elies  &  Wood.  Monogr.  Brit.  Grapt.  pt  1. 
Pal.  Soc.  vol.  for  1902.  p.100,  pi. 13,  fig.7a-f 

Phyllograptus  angustifolius  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t. 
1902.  p.554,  556,  570 

Specimens  referable  to  this  species  are  found  in  all  three  horizons  of  the 
Deep  kill  section  ;  the  form  does  not  however  attain  its  typical  expression  till 
the  third  horizon  (with  Diplograptus  den  tat  us),  while  the 
specimens  of  the  first  horizon  (with  Tetragraptus)  approach  P.ilici- 
f  oli  us  and  suggest  a  genetic  connection  between  the  two.  The  typical 
material  possesses  the  following  distinguishing  characters. 

Description.  Rhabdosome  consisting  of  four  elongate,  semielliptie 
branches,  which  have  nearly  ecpial  width  throughout  or  are  a  little  wider 
near  the  sicular  end.  Thecae  in  contact  throughout,  numbering  11  to  13 
in  10  mm,  being  very  little  curved  and  directed  at  a  uniform  angle 
obliquely  upward,  the  inclination  increasing  somewhat  toward  the  anti- 
sicular  end.  The  thecae  of  the  sicular  end  are  in  their  proximal 
portion  nearly  horizontal  and  slightly  bent  down  in  their  distal 
portion. 

The  apertures  of  this  species  are  very  characteristic,  the  mucronate 
extension  of  the  lower  part  of  the  same  being  much  longer  than  that  of 
the  upper,  so  that  the  margin  of  the  aperture  appears  to  recede  in  an 
upward  direction.  This  extension  attains  a  length  of  one  and  one  half  times 
the  width  of  the  thecae. 

Position  and  localities.  This  species  occurs  in  all  three  horizons  of  the 
Deep  kill  section.  It  finds  its  typical  development  in  the  last  horizon  (with 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


713 


Fig\97  Ph yllograptus  angusti- 
f  o  1  i  u  s  Hall.  Middle  portion  of  rhab- 
dosome  enlarged.  Shows  the  shape  of 
the  apertures  in  compressed  state,  and 
the  central  canal.  Deep  kill.  x4.  8 


Diplograptus  dentatus),  specially  in  the  lower  part  of  the  same, 
exposed  in  the  Ashhill  quarry  at  Mt  Moreno,  Hudson,  where  it  is  very 
common.  Hall’s  t}pes  came  from  the  shales  of  Point  Levis;  but,  as  no 
associated  forms  are  mentioned,  the  horizon  is  not  determinable  from  his  data. 
Ami,  however,  cites  it  from  several  localities  near  Point  Levis  and  Quebec  in 
association  with  species  of  the  zones  of  D  i  d  y  m  ograp  t  u  s  bifid  us 
and  of  Tetragraptus.  It  can  be  thus  inferred 
that,  in  the  Quebec  region  as  well  as  at  the  Deep 
kill,  it  ranges  through  several  zones.  A  similar 
range  of  the  species  has  been  observed  by  Elies 
and  Wood  in  Great  Britain.  Also  in  Sweden 
(Scania)  it  appears  to  be  a  form  of  the  Tetra¬ 
graptus  horizon  as  well  as  of  the  Phyllograptus 
cf.  typus  zone.  Brogger  found  it  associated  with 
P.  typus  and  numerous  varieties  or  mutations 
of  the  two  species,  in  the  upper  beds  of  the 

Phyllograptus  shale  of  Christiania.  Holm  obtained  his  material  from  the 
gray  Orthoceras  limestone  of  Oeland. 

Hemarhs.  While  this  species  persists  beyond  the  range  of  P.  ilici- 
folius  into  the  horizon  with  Diplograptus  dentatus,  it  begins 
in  the  Tetragraptus  beds,  where  P.  ilicifolius  is  prevalent,  with  forms 
that  possess  the  long  linear  outline  of  P.  angustifolius  and  the 
uniform  direction  and  curvature  of  the  thecae  in  the  middle  portion,  a 
characteristic  that  seems  to  be  dependent  on  the  narrow  development  of 
the  rhabdosome,  while  in  the  antisieular  part  the  thecae  are  still  more 
ascending  than  in  P.  angustifolius,  but  not  so  strongly  as  in  typical 
P.  ilicifolius.  The  apertural  mucros  are  not  yet  as  strongly  developed 
as  in  the  P.  angustifolius  from  the  higher  horizon,  but  of  the  same 
character,  viz  extensions  of  the  lower  margins.  Indeed  from  a  comparison 
of  the  drawings  of  the  apertural  extensions  of  P .  angustifolius  fur¬ 
nished  by  Holm  [text  fig.94J  with  those  of  P .  ilicifolius  [text  fig.  95], 
it  is  to  be  inferred  that  they  are  of  exactly  the  same  character  and  differ 


714 


NEW  YORK  STATE  MUSEUM 


only  in  relative  size.  The  form  from  the  quarry  beds  appears  to  be 
transitional  between  the  preceding  older  mutation,  still  closely  related 
to  P.  ilicifolius,  and  the  succeeding  typical  form  in  the  uppermost 
horizon. 

Phyllograptus  anna  Hall 

Plate  15,  figures  23-30 

Phyllograptus  anna  Hall.  Canadian  Organic  Remains,  decade  2.  1865.  p.124, 

pi.  16,  tig.  11- 16 

Phyllograptus  anna  Lapworth.  Roy.  Soc.  Can.  Proc.  and  Trans.  1886. 
4:168 

Phyllograptus  anna  Ami.  Geol.  Sur.  Can.  Rep’t,  ser.  2.  1889.  v.3,  pt  2, 

p.H6k 

Phyllograptus  anna  Gurley.  Jour.  Geol.  1896.  4:294 
Phyllograptus  anna  Elies.  Quar.  J our.  Geol.  Soc.  1898.  54:494,  fig.16 

Phyllograptus  anna  Elies  &  Wood.  Monogr.  Brit.  Grapt.  Pal.  Soc.  vol.  for  1902. 
p.101,  pi. 13,  fig.6a-f 

Phyllograptus  anna  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.566,  571 

Description.  Rhabdosome  small,  a  single  very  large  specimen  attain¬ 
ing  13  mm,  while  ordinarily  large  specimens  measure  only  8  and  9  mm  in 
length  ;  the  maximal  width  of  the  largest  specimen  was  found  to  be  5 . 2  mm ; 
branches  broadly  semioval,  attaining,  as  a  rule,  their  greatest  width  near  the 
antisicular  end,  which  often  appears  truncated.  Thecae  in  contact  through¬ 
out,  very  closely  arranged,  numbering  16  to  20  in  10  mm;  those  near  the 
sicula  being  directed  outward  and  curved,  the  curvature  gradually  increasing 
toward  the  middle  where  they  are  strongly  curved ;  becoming  more  ascend¬ 
ing  toward  the  antisicular  end,  where  they  are  nearly  straight  and  subparallel 
to  the  axis  of  the  rhabdosome.  Apertural  margins  regularly  and  deeply 
concave,  mucronate  extensions  of  the  apertures  long,  narrow  and  in  the 
compressed  state  of  nearly  uniform  width,  or  sometimes  appearing  thickened 
or  club-shaped  at  their  distal  ends,  when  more  than  the  lateral  margin  of 
the  extension  is  exposed.  The  character  and  length  of  the  sicula  has  not 
been  ascertained.  A  short  stout  sicular  spine  has  been  noticed  in  several 
specimens. 


GRAPTORITES  OK  NEW  YORK.  PART  t 


715 


Fig.  98  Phyllograptus 
anna  Hall.  Marginal  por¬ 
tion  of  rhabdosome,  to  show 
the  appearance  of  the  thecal 
apertures  in  the  compressed 
condition.  Deep  kill.  x4.5 


Position  and  localities.  In  the  last  layers  of  graptolite  bed  2  (Tetra- 
graptus  horizon),  and  throughout  the  horizon  with  Di  dymograptus 
b  i  f  i  d  u  s .  Also  in  the  next  horizon  with  Diplograptus  dentatus 
as  well  at  the  Deep  kill,  as  at  Mt  Moreno.  In  Canada  this  form  has  been 
found,  according  to  Hall  and  Lapworth,  only  in  the 
St  Anne  beds,  representing  there  the  horizon  with 
Didymograptus  b  i  f  i  d  u  s .  Ami  records  it  also 
from  an  outcrop  near  the  city  hall  of  Levis,  in  association 
with  Didymograptus  bifid  us,  etc.  and  from  a 
locality  on  the  Chaudiere  river.  Gurley  observed  it  also 
in  suites  of  graptolites  from  the  Beekmantown  beds  of 
Arkansas  and  Nevada.  It  is  known  from  the  Middle 
Skiddaw  slates  of  the  Lake  district  of  England,  where  it  is  found  associated 
with  P.  angustifolius;  and  from  south  Scotland. 

Remarks.  This  form  is  easily  recognized,  as  pointed  out  by  Hall  and 
Elies,  by  its  small  size  and  the  great  number  of  thecae  in  a  given  unit  of 
length.  This  is  greater  than  in  any  other  species  and  goes,  in  the  Deep 
kill  specimens,  beyond  the  number  obtained  by  the  above  cited  authors. 
The  greater  width  of  the  end  is  also,  though  not  an  unfailing,  yet  a  strik¬ 
ing  character  of  the  majority  of  the  specimens,  and  the 
acute  slender  form  of  the  mucros  serves  also  to  distin¬ 
guish  this  species  from  the  associated  forms;  specially 
from  dwarfed  specimens  of  P.  ilicifolius,  which 
have  been  noticed  in  the  material. 

The  specimens  observed  in  the  last  horizon  of  the 
Deep  kill  section  have  a  still  more  condensed  aspect, 
their  thecae  number  as  much  as  22  in  the  space  of 
10  mm,  and  the  total  size  attained  is  not  more  than  3.6  mm.  They  represent 
clearly  a  last  dwarfed  and  paracmic  mutation  of  the  species,  which  might  be 
designated  as  P.  anna  mut.  ultimus  [pl.15,  fig.29,  30]. 

In  the  beds  with  Diplograptus  dentatus  exposed  at  Mt  Moreno 
a  form  of  P.  anna  is  extremely  common,  which,  while,  by  its  outline, 


Fig.  99  Phyllograptus 
anna  Hall.  Ashhill  quarry 
at  Mt  Moreno.  x5 


716 


NEW  1‘QRK  STATE  MUSEUM 


close  arrangement  and  direction  of  thecae,  still  falling  within  the  boundaries 
of  the  original  description  of  that  species,  differs  distinctly  by  the  absence 
of  the  long  apertural  macros  and  generally  less  compact  or  truncate  shape. 
Its  outline  is  uniformly  oval,  with  the  broader  part  forming  the  similar  end 
[pi. 15,  fig.28,  and  text  fig.99],  and  it  is  always  small,  none  of  the  specimens 
surpassing  6  mm  in  length.  This  mutation  I  propose  to  designate  as  P.  anna 
mut.  pygmae  us.  It  is  however  possible  that  this  is  a  last  and  pygmaean 
mutation  of  P .  ilicifolius. 

Several  specimens  of  this  species  distinctly  show  a  fine  chitinous  thread 
passing  longitudinally  through  the  rhabdosome,  which  has  the  appearance  of 
being  the  nema  of  the  sicula,  incorporated  into  the  rhabdosome. 

Genus  incertae  sedis 

STROPHOGRAPTUS  gen.  llOV. 

Etymology  :  slrophos,  bent ;  grapho ,  I  write. 

Description.  Bundles  of  long,  thin,  llexuous,  carbonaceous,  subparallel 
fibers  which  do  not  bifurcate.  Thecae  not  projecting  from  branch  or 
rhabdosome  (?),  thecal  apertures  appressed  in  one  row.  Virgula  not  observed. 
Apertures  connected  by  median  depressions  (perhaps  of  secondary  origin  and 
indicating  the  position  of  the  coenosarc). 

Remarks.  The  type  species  of  this  genus,  S  t  r  o  p  h  o  g  r  a  p  t  u  s 
tricho  manes,  occurs  in  numerous  bundles  of  fibers  on  the  slabs  of 
graptolite  bed  6,  zone  with  Diplograptus  dentatus.  Bundles  of 
finer  and  unbranchiug  fibers  are  also  found  on  slabs  of  the  preceding  zones. 
As  these  masses  are  intermixed  with  the  typical  graptolites,  consist  of  the 
same  carbonaceous  matter  and  exhibit  regularly  distributed  thecal  apertures, 
but  can  not  be  referred  to  any  of  the  graptolite  genera  with  which  they  are 
found  associated,  they  must  be  recognized  as  representing  a  separate  generic 
type. 

Emmons  established  a  genus,  Nemagrapsus  [1855,  2:109],  for  threadlike, 
chitinous  bodies,  and  described  two  species,  viz  N.  elegans  and 
N  .  capillar  is.  The  first  was  recognized  by  Hall  as  being  based  on  a 


GRARTOLtTES  OE  NEW  YORK.  1’ART  1 


71? 

fragment  of  his  Coenograptus  gracilis,  and  the  second  species  has 
then  been  considered  as  the  genotype  of  Nemagraptus.  This  genus  has  had  a 
somewhat  checkered  career ;  at  first  it  was  not  recognized  by  some,  as  Hall, 
but  later  its  right  of  existence  was  asserted  by  Lapworth  and  Gurley.  Dr 
Gurley  collected  identical  material  in  the  same  horizon  as  Emmons  (Normans- 
kill  shale,  cited  by  Emmons  as  Tacouic  slates  of  Columbia  county).  From 
this  genus,  as  based  on  Nemagrapsus  capillar  is,  m  which  Emmons 
was  unable  to  find  apertures,  the  present  one  is  distinguished  by  its  lack  of 
branching1.  Gurley  has  erected  still  another  genus,  Phycograptus,  for 
similar  threadlike  bodies,  which  also  have  been  frequently  observed  by  the 
writer  in  the  Normanskill  shales.  This  genus,  to  which  two  species  are 
referred,  is  likewise  represented  by  unbranching,  long,  carbonaceous 
fibers  with  a  central  row  of  pits  or  apertures,  but  the  fibers  are 
distinctly  segmented  by  partitions  midway  between  the  pits  and  possess 
marginal  grooves.  The  writer  has  obtained  a  specimen  of  Phycograptus 
at  Mt  Moreno,  to  be  more  fully  described  and  figured  later  on,  which  shows 
a  short  cylindric  axis,  from  which  the  innumerable  Phycograptus  fibers 
proceed  in  verticillate  arrangement.  Whether  the  fibers  of  Strophograptus 
are  similarly  connected  with  a  stem  is  not  known  as  yet ;  but  their  regular 
subparallel  arrangement  in  bundles  would  indicate  that  the  component  fibers 
of  these  bundles  belong  together. 

Strophograptus  trichomanes  sp.  nov. 

Plate  4,  figures  17-20 

Description.  Bundles  of  thin,  flexuous  fibers  (branches?),  the  fibers 
attaining  a  length  of  13  cm  and  a  width  of  .2  mm.  Thecal  apertures  circular 
to  transversally  oval  pits  on  slight  prominences,  numbering  about  8  in  10  mm ; 
fibers  contracted  between  the  pits  by  one  fourth  or  one  third  of  their  width. 

1  Elies  and  Wood  have  meanwhile,  in  the  third  part  of  the  Monograph  of  the  British 
Graptolites  very  properly  replaced  Hall’s  term  Coenograptus,  which  though  younger  has 
been  generally  accepted,  by  Emmons’s  term  Nemagraptus  which  has  the  right  of  priority. 


718 


NEW  YORK  STATE  MUSEUM 


Position  and  locality.  Zone  with  Diplograptus  dentatus  at 
the  Deep  kill. 

Pemarhs.  Similar  strands  of  long,  fine  threads  occur  also  in  the  two 
subjacent  horizons.  They  belong  to  another  species,  as  suggested  by  the 
smaller  width  of  the  fibers,  if  they  are  at  all  congeneric  with  this  fossil,  for 
no  thecal  apertures  have  as  yet  been  discerned  on  them. 

Suborder  B  graptoloidea  axonophora  Freeh 
Family  diplograptidae  Lapworth 
diplograptus  McCoy.  1854 

The  genus  Diplograptus  makes  its  first  appearance  in  the  uppermost 
of  the  graptolite  beds  of  the  Deep  kill  (graptolite  bed  6,  horizon  with 
D.  dentatus)  and  does  not  attain  the  acme  of  its  development  till  the 
Trenton  period.  We  shall,  for  this  reason,  reserve  the  more  detailed  charac¬ 
terization  and  discussion  of  this  genus  for  the  next  memoir,  which  will  contain 
the  descriptions  of  the  graptolites  of  Trenton  and  later  age,  and  mention  here 
provisionally  only  a  few  of  the  most  important  facts. 

The  genus  was  originally  proposed  by  McCoy  in  place  of  Barrande’s 
Diprion,  a  name  which  was  preoccupied.  Like  Barrande’s  term,  it  was 
intended  to  include  all  forms  with  two  series  of  thecae.  By  the  separation  of 
several  groups  of  biserrate  forms  as  genera,  as  Climacograptus  and  Glosso- 
graptus,  the  genus  has  been  restricted  to  diprionid  forms  with  a  straight  vir- 
gula,  inclined  thecae  and  normal,  mucronate  or  nonmucronate  apertures.  The 
various  forms  comprised  by  this  definition  have  since  been  subdivided  by 
Lapworth  [1873],  and  Freeh  has  proposed  [1897]  a  division  into  two  groups 
according  to  the  presence  or  absence  of  apertural  spines. 

The  four  species  described  here,  viz  D.  dentatus,  longicauda- 
tus,  la  xus  and  in  util  is,  are  evidently  to  be  referred  to  Diplograptus 
proper. 

It  has  been  demonstrated  by  the  present  writer  that  the  rliabdosomes  of 
Diplograptus  are  parts  of  a  person  of  a  higher  order  (synrhabdosome),  thev 


ORATTOLITES  OF  NEW  YORK,  PART  1 


719 


being  united  in  the  center  by  a  funicle  and  a  central  disk  [p.528],  and  that 
from  the  latter  originate  the  gonangia  in  which  new  siculae  are  produced ; 
and  Wiman  has  shown  that  the  apparent  biserial  arrangement  of  the  thecae  is 
produced  by  one  series,  the  thecae  budding  alternately  on  opposite  sides 
|>538], 

Diplograptus  dentatus  Brongniart  sp. 

Plate  17,  figures  10-13 

Fucoides  dentatus  Brongniart.  Hist.  Veget.  Foss.  1828.  l:70fp,  pi. 6, 

fig.9-12 

Graptolithus  pristiniformis  Hall.  Geol.  Sur.  Can.  Rep’t.  1857. 
p.133 

Diplograptns  pristiniformis  Hall.  Geol.  Snr.  Can.  decade  2.  1865. 

p.llOff,  pl.13,  lig.15-17 

Diplograptns  pristiniformis  Nicholson.  Quar.  Jour.  Geol.  Soc.  1868. 
24:140,  pi. 5,  fig.14,  15 

Diplograptns  dentatus  Hopkinson  &  Lapworth.  Ibid.  1875.  31:656ff,  pl.34, 

lig.5a-k 

Diplograptns  dentatus  Ami.  Geol.  Sur.  Can.  Rep’t,  ser.2.  1889.  v.3,  pt  2, 

p.H7k 

Diplograptus  dentatus  Gurley.  Jour.  Geol.  1896.  4:  298 

Diplograptns  dentatus  Elies.  Quar.  Jour.  Geol.  Soc.  1898.  54 :517ff 

Diplograptus  dentatus  Ruedetnann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.  570 

This  type,  which  is  very  common  in  the  graptolite  beds  at  the  dam  in 
the  Deep  kill  section  and  at  Mt  Moreno,  not  only  presents  a  great  variety 
of  appearances,  some  of  which  are  represented  by  the  camera  tracings  but  also 
considerable  variations  in  its  dimensions. 

Description.  The  rhabdosomes  are  as  a  rule  narrow,  attaining  their  full 
width  (1.8  to  2.1  mm)  at  an  early  stage  of  their  growth,  and  maintaining  this 
throughout.  Perfect  specimens  attaining  a  length  of  45  mm  have  been 
observed,  but  fragments  indicate  that  they  grew  still  beyond  that  size.  The 
thecae  are  closely  arranged;  they  number  10  in  10  mm  in  most  specimens,  but 
in  the  earliest  parts  of  a  few  number  14  to  16  and  in  the  later  portions  of 


720 


NEW  YOKE  STATE  MUSEUM 


the  rhabdosome  as  much  as  1 2.  In  normal  specimens  they  appear  as  subacute 
denticulations,  are  narrow,  forming  an  angle  with  the  axis  not  greater  than 
20°,  are  free  for  one  tliml  of  their  length,  and  possess  a  slightly  concave  outer 
margin,  slightly  mucronate  or  acute  apertural  extension,  straight  or  slightly 
concave  apertural  margin,  which  forms  an  angle  of  80°  to  90°  with  the  axis. 
There  are  however  other  specimens  in  which  the  outer  margins  are  strongly 
rounded,  the  apertural  margin  is  straight  or  slightly  convex,  and  some  in 

which  the  thecae  appear  to  be  free  for  at  least  one 
half  or  even  two  thirds  of  their  length. 

The  virgula  which  is  often  seen  to  extend  through 
the  rhabdosome  is  straight  and  distinct,  but  apparently 
not  so  strong  as  indicated  by  Hall’s  figure.  A  strong 
median  sicular  spine,  about  5  mm  long,  has  been 
observed  in  several  specimens,  as  well  as  two  short 
lateral  spinules. 

Position  and  localities.  This  is  the  most  char¬ 
acteristic  and  common  graptolite  of  the  last  horizon 
in  the  Deep  kill  section  and  is  there  restricted  to  the  same.  It  occurs  with 
equal  frequency  in  the  somewhat  older  bed  at  Mt  Moreno,  near  Hudson. 
In,  Canada  it  is  found  in  the  homotaxial  Point  Levis  zone.  Gurley  records 
it  from  Arkansas.  In  the  Upper  Skiddaw  slates  (Ellergill  beds)  it  has  been 
observed  in  many  localities.  Hopkinson  and  Lapworth  report  it  also  from 
the  Upper  Arenig  of  Ramsey  island  and  the  Llanvirn  quarry  in  Wales.  In 
Sweden  it  has  been  found  at  the  top  of  the  Phyllograptus  zone  (subzone 
with  Phyllograptus  cf.  t  y  p  u  s  )  . 

Pemarhs.  The  great  variety  of  appearances  as  well  as  of  dimensions 
of  this  species  has  been  commenfed  on  by  Hopkinson  and  Lapworth,  and 
Elies.  It  is  also  very  noticeable  in  the  Deep  kill  material  and  still  more 
so  in  that  from  the  Mt  Moreno,  which  contains  numerous  specimens  that 
attain  a  width  of  2.6  mm — thus  surpassing  considerably  the  maximal  width 
observed  by  Miss  Elies — and  have  not  more  than  nine  thecae  in  the 
space  of  10mm.  These  specimens  differ  so  materially  from  the  originals  of 


Fig.  100  D  i  p  1  o  g-  r  a  p  t  u  s 
ilentatus  Brongniart  sp. 
Fragment  of  middle  portion 
of  rhabdosome.  Shows  two 
aspects  of  thecae.  Ashhill 
quarry  at  Mt  Moreno.  x5 


GRAPTOLITES  OF  NEW  YORK,  FART  l 


721 


Hall’s  description  that  they  would  have  to  be  separated  if  they  were  not 
intermixed  with  numerous  transitional  and  some  typical  forms.  It  is  how¬ 
ever  unmistakable  that  here  a  strong  tendency  to  the  production  of  a  coarser 
form  is  displayed. 

Diplograptus  inutilis  Hall 

Plate  16,  figures  12,13 

Diplograptus  inutilis  Hall.  Geol.  Sur.  Can.  decade  2.  1865.  p.l  11 ,  pi. 13, 

fig.14 

Diplograptus  inutilis  Gurley.  Jour.  Geol.  1896.  4:298 

Diplograp  tus  inutilis  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 
p.570 

A  few  specimens  of  a  diprionid  form  agree  with  the  incomplete 
original  description  and  figures  of  this  not  very  well  known  species. 

Description.  The  rhabdosome  was  probably  of  moderate  size  (length 
of  one  specimen  7  mm,  of  the  fragment  of  another  11.4  mm);  attaining  a 
maximal  width  of  2.4mm,  from  which  it  gradually  tapered  to  the  antisicular 
end.  The  thecae  are  curved;  number  12  to  10  mm;  are  inclined  about  40°; 
in  contact  for  one  half  of  their  length.  Their  outer  margins  are  strongly 
curved,  first  convex,  then  concave,  abruptly  bending  outward  near  the 
apertures  and  forming  a  blunt  mucronate  extension  of  the  aperture,  which 
extends  at  right  angle  to  the  axis.  The  aperture  is  straight  or  slightly  con¬ 
vex  and  also  approximately  perpendicular  to  the  axis.  Virgula  very  strong. 
Appendages  of  sicular  end  not  observed. 

Position  and  locality.  Very  rare  at  the  Deep  kill  in  the  horizon  with 
Diplograptus  dentatus,  to  which  it  is  also  restricted  in  Canada 
[  Hall  and  Gurley]. 

Remarhs.  The  specimens  here  figured  agree  with  Hall’s  originals  in 
the  width  of  the  rhabdosome,  the  perpendicular  position  of  the  free  portions 
of  the  thecae  in  regard  to  the  axis,  the  number  of  thecae  in  a  given  space 
and  the  mucronate  prolongations  of  the  apertures.  The  type  specimens  were 
also  found  in  the  same  association,  in  the  Quebec  shales  of  Point  Levis,  as  those 
here  described. 


NEW  YORK  STATE  MUSEUM 


722 


Diplograptus  laxus  sp.  nov. 

Plate  16,  figures  1-10 

Diplograptus  sp.  nov.  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 

p.571 

A  small  species  of  Diplograptus,  presenting  some  very  peculiar  characters, 
occurs  frequently  in  bed  7  (zone  with  D .  dentatus)  of  the  Deep  kill 
section  and  in  beds  of  the  same  horizon  at  Mt  Moreno. 

Description.  Primary  disk  not  observed.  Nema  short,  attaining  a  length 
of  9  mm  or  more,  relatively  stout,  and  expanded  into  a  cucumber-shaped 
vesicle  [pi. 16,  fig.3].  Rhabdosome  small  (maximal  length  observed  13.4  mm, 
prevailing  length  only  about  10  mm)  and  narrow,  as  a  rule  not  wider  than 
1  mm,  of  nearly  uniform  width.  Sicular  end  provided  with  two  short, 
curved  lateral  and  a  short  median  spine  (the  former,  apertural  spines  of 
first  thecae,  the  latter,  probably  median  spine  of  sicula).  Thecae  number¬ 
ing  10  to  12  in  10  mm,  curved,  the  angle  of  inclination  increasing  from  10°  in 
the  basal  to  30°  in  the  apertural  portion  of  the  thecae ;  overlapping  but 
one  fourth  of  their  length ;  their  outer  margin  concave,  first  subparallel  to 
the  axis  of  the  rhabdosome  and  then  turning  rather  abruptly  outward. 
The  apertural  margin  slightly  convex  and  oblique  to  the  general 
direction  of  the  thecae,  forming  a  short,  blunt  apertural  denticle  in  the  com¬ 
pressed  material. 

Position  and  localities.  Frequent  on  the  surface  of  graptolite  bed  7 
(belonging  to  the  zone  with  D .  dentatus)  of  the  Deep  kill  section  and  in 
similar  association  at  Mt  Moreno  near  Hudson. 

Remarks.  I  am  not  aware  of  any  form  from  which  this  species  could 
not  be  readily  distinguished  either  by  its  small  size  or  the  peculiar  shape 
of  its  thecae.  The  similarly  minute  D  .  p  u  t  i  1 1  u  s  Hall,  which  occurs  in 
the  Upper  Champlainic  shales,  has  its  thecae  much  less  inclined  and  becoming 
in  their  distal  portions  subparallel  to  the  rhabdosome  instead  of  increasing 
in  divergence  as  the  thecae  of  this  species  do.  The  same  difference 
exists  between  this  species  and  the  equally  old,  small  European  form, 


GRAPTOLITES  OF  NEW  YORK,  TART  1 


723 


D.  tereti  usculus  Hisinger  sp.  Freeh  describes  [1897,  p.628]  a  form 
from  a  north  German  glacial  boulder  with  thecae  projecting  “  swallow-nest¬ 
like”  as  D.  sertularioideus.  With  that  species  our  specimens 
specially  those  which  were  apparently  slightly  macerated  before  becoming 
buried  [phi 6,  fig.  8],  possess  some  similarity  in  the  shape  of  the  thecae. 
The  consideration  of  a  possible  identity  of  the  two  species  is  however 
precluded  by  the  slenderness  of  the  rhabdosome  of  our  form  when 
compared  with  the  broader  and  more  compact  shape  of  the  European 
species. 

A  feature  worth  special  mention  is  the  apparently  vesicular  expansion 
of  the  nema.  This  has  hitherto  not  been  observed  in  any  American  species 
of  Diplograptus,  though  it  is  known  to  European  paleontologists  from 
D.  vesiculosus  Nich.  and  D .  appendiculatus  (Tornq.  ms) 
em.  Elies. 


Diplograptus  longicaudatus  sp.  nov. 

Plate  16,  figure  11 

Description.  Rhabdosome  small,  attaining  its  full  width  (2 . 8  mm)  near 
the  sicular  end.  The  thecae  are  closely  arranged  (16  in  10  mm);  inclined  at 
an  angle  of  35°  to  40° ;  in  contact  for  about  half  their  length ;  their  outer 
margins  strongly  concave  ;  the  apertural  margins  strongly  convex  ;  the  blunt 
marginal  angles  turned  downward.  Virgula  stout  and  long,  Sicula  not 
observed. 

Position  and  locality.  Extremely  rare  in  the  horizon  with  Diplo¬ 
graptus  dentatus  at  the  Deep  kill. 

Remarks.  This  species  is  based  on  a  single  specimen.  This  could  in 
some  of  its  features,  be  called  an  extreme  form  of  D.  d  e  n  t  a  t  u  s,  notably  in 
the  possession  of  the  long  sicular,  terminally  filiform  spine  (virgella)  and  the 
close  arrangement  of  the  thecae.  It  differs,  however,  too  much  from  that 
species  in  the  character  and  inclination  of  its  thecae  to  be  safely  identified 
with  it. 


724 


NEW  YORK  STATE  MUSEUM 


glossograptus  Emmons.  1856 

The  author  of  the  genus  saw  its  distinctive  characters  in  the  ligulate 
outline  and  rounded  extremities,  as  its  name  implies,  but  not  in  the  presence 
of  the  long  spines,  for  he  described  in  the  same  paper  an  equally  spinous  form 
under  Diplograptus.  Hall  |  1865,  p.43  ]  did  not  recognize  the  genus,  as,  in  his 
opinion  it  is  based  on  a  species  of  Diplograptus  with  ciliate  appendages  on 
the  cell  margins,  “  and  no  characters  are  given  to  show  its  generic  distinction 
and  Freeh  [1897,  p.631  ]  concurs  with  Hall  in  this  view,  stating  that,  as  these 
appendages  show  all  gradations  in  the  diprionid  graptolites  and  in  Pristio- 
graptus,  they  are  not  suited  for  generic  distinctions.  On  the  other  hand,  the 
same  author  divides  the  species  of  the  genus  Diplograptus  into  two  sections,  one 
without  and  one  with  thecal  spines,  considering  the  latter  section  as  coin¬ 
ciding  with  the  genus  Glossograptus,  as  defined  by  Lapworth.  The  latter 
author  [1873,  p.504],  however,  lias  proposed  to  restrict  the  term  to  forms  in 
which,  as  in  Emmons’s  type,  not  only  is  each  theca  furnished  with  two  long 
spines  or  fibers,  extending  outward  from  the  angles  of  the  aperture,  but  the 
polypary  itself  is  ornamented  in  addition  with  two  opposite  longitudinal  rows 
of  gigantic  isolated  spurs,  developed  along  the  median  line  of  the  periderm 
at  right  angles  with  the  thecae.  Elies  1 1898,  p.521f¥]  unites  under  Glosso¬ 
graptus  all  diprionid  species  with  long  thecal  spines,  which  indeed  seem 
to  form  a  small  characteristic  group.  We  give  the  genus  here  the  same 
compass. 

Glossograptus  hystrix  sp.  nov. 

Plate  16,  figures  27-29 

Glossograptus  sp.  nov.  Ruedemanu.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 

p.571 

Description.  Sicula,  nema  and  primary  disk  not  observed.  Rhabdo- 
some  small  (4 . 5  mm  length  of  largest  specimen  observed),  relatively  wide 
(about  1 . 6  mm),  with  subparallel  margins.  Thecae  closely  arranged,  num¬ 
bering  20  in  10  mm,  inclined  at  the  low  angle  of  about  25°,  overlapping  three 
fourths  of  their  length,  exhibiting  straight  outer  margins  and  straight 


GItAPTOLlTES  OF  NEW  YOKE.  I’ART  1 


apertural  margins,  which  are  approximately  perpendicular  to  the  axis. 
Entire  rhabdosome  bristling  with  straight,  long  (1 . 4  mm)  spines,  four  of  which 
are  placed  at  the  sicular  end  and  directed  parallel  to  the  axis,  while  those  in 
the  middle  of  the  rhabdosome  have  a  horizontal  position  and  those  found 
near  the  antisicular  end  are  directed  upward.  Each  theca  is  provided 
with  at  least  two  spines,  which  are  situated  on  either 
side  of  the  aperture,  and  apparently  also  with  others 
on  the  lateral  faces  or  the  outer  margin  of  the  thecae. 

Position  and  localities.  This  form  is  rare  (only 
four  specimens  having  been  found)  in  the  shale  at  the 
dam,  belonging  to  the  horizon  with  Diplograptus 
d  e  n  t  a  t  u  s  and  Clim  acograptus?  anten- 
n  ariu  s;  and  in  beds  at  Mt  Moreno,  containing  forms 

^  Fig.  101  Glossograptus 

of  an  early  phase  ot  this  horizon.  hystrix  sp.  nov.  Khabdo- 

1  some.  Deep  kill.  xS 

Remarks.  From  the  homotaxial  horizon  in  the 
Ellergill  beds  in  England  not  less  than  three  species  have  become  known, 
viz  G .  f  i  m  b  r  i  a  t  u  s ,  h  i  n  c  k  s  i  i  and  a  r  m  a  t  u  s .  With  the  last  of 
these,  the  form  here  described  possesses  the  most  similarity,  both  agreeing 
in  the  dimensions  and  shape  of  the  rhabdosome;  the  Ellergill  form,  how¬ 
ever,  has  fewer  and  longer  spines,  which  are  reflexed. 

Glossograptus  echinatus  sp.  nov. 

Plate  16,  figures  30-32 

Description.  Primary  disk,  neina  and  sicula  not  observed.  Rhabdo- 
some  of  medium  size,  a  perfect  specimen  measuring  19.5mm,  wider  in  the 
middle  than  at  the  ends,  about  1 . 2  mm  wide  at  the  sicular  end,  3  mm  in 
the  middle  (excluding  the  spines)  and  2.2  at  the  antisicular  end.  Thecae, 
narrow  tubes  numbering  12  in  10  mm,  inclined  at  15°,  three  times  as  long 
as  wide,  in  contact  about  one  half  of  their  length ;  their  outer  margins  con¬ 
cave;  their  apertural  margins  straight,  passing  obliquely  to  the  axis  of  the 
thecae;  their  outer  margins  protracted  into  stout  spines  (1.5mm  long),  which 
are  approximately  perpendicular  to  the  axis  of  the  rhabdosome.  The  sicular 


726 


NEW  YORK  STATE  MUSEUM 


end  of  the  latter  provided  with  two  longer  outer  and  two  shorter  inner 
spines. 

Position  and  locality.  V  ery  rare  in  the  horizon  with  Dip  log  rapt  us 
d  entatus  at  the  Deep  kill. 

Pemarhs.  This  species  appears  to  be  a  vicarious  form  of  the  British 
G .  fimbiiatus  of  the  same  horizon,  similarly  as  G .  h  y  s  t  r  i  x 

resembles  G.  arm  at  us,  another  species  of  tbe  British 
Ellergill-  beds.  Our  type  possesses  a  shape  of  the 
rhabdosome,  thecae  and  spines,  much,  like  G .  fimbri- 
atus,  blit  is  larger,  broader  and  has  larger  and  less 
closely  arranged  thecae.  The  spines  are  also,  judging 
from  the  drawings  of  the  British  form,  stouter  in  our 
species.  In  the  character  of  the  spines  the  present 
species  would  seem  to  approach  G .  hincksii,  from  which  it  differs 
however  in  the  relative  distance  of  these  spines,  which  are  more  closely 
set  in  the  Deep  kill  form  (one  to  each  theca,  while  in  G.  hincksii, 
according  to  Elies,  probably  only  every  second  or  third  theca  possessed 
spines). 

trigonograptus  Nicholson.  1869 

Nicholson  proposed  this  genus  [1869,  p.231]  for  a  form,  which  was 
discovered  by  him  in  the  upper  Skiddaw  slates  and  cited  the  following  as 
its  principal  characters :  “  Frond  simple,  diprionidian,  rapidly  tapering 

toward  the  base  and  having  perfectly  plain  lateral  margins  without  denticles. 
Cell  partitions  alternating  with  one  another,  and  springing  from  an  undulat¬ 
ing  or  zigzag  solid  axis.  A  common  canal  is  probably  present,  in  which 
case  the  axis  must  be  excentric ;  but  the  evidence  on  this  point  is 
incomplete.” 

Of  the  features  noted  here,  only  the  perfectly  plain  margins  without 
denticles  remain  as  a  distinguishing  character  from  the  other  Diplograptidae ; 
for  the  frond  is  rapidly  tapering  only  in  the  type  species,  T.  lanceola- 
t  u  s ,  but  not  in  the  species  here  described,  which  has  also  been  referred 
by  Nicholson  to  his  new  genus ;  the  cell  partitions  alternate  in  all  Diplo- 


Fig.102  Glossograptus 
echinatus  sp.  nov.  The¬ 
cae.  Deep  kill.  x6 


GRAl’TOLITES  OF  NEW  YORK,  TART  1 


727 


graptidae  on  account  of  their  origin  by  alternate  budding ;  and  the  axis 
was  originally  described  as  having  a  zigzag  form  in  T .  lanceolatus, 
while  that  of  T .  ensiformis  has  always  been  known  to  be  straight  or 
but  slightly  undulating  [pi.  17,  fig. 4].  Nicholson’s  observation  of  a  zigzag 
axis  in  the  type  species  appears  not  to  be  verified  by  Elies,  who,  after 
inspection  of  that  author’s  type  material,  cites  the  greater  inclination  of 
the  thecae  in  T .  lanceolatus  as  the  only  difference  between  the  two 
species  of  the  genus. 

Thus  the  indentate  margin  remains  the  only  distinctive  character  of 
the  genus.  This  straight,  undivided  margin  is  due  to  a  peculiar  obliquity 
of  the  apertures  to  the  axis  of  the  thecae,  as  some  of  our  specimens  clearly 
show7-  [fig.9],  the  apertural  angles  of  the  thecae  being  approximately  equal  to 
their  inclination  angles,  both  forming  thus  alternating  angles  between 
parallels. 

The  oblique  position  of  the  apertures  is  also  the  only  difference  I  am  aware 
of,  between  this  genus  and  Diplograptus ;  the  former  should,  hence,  probably 
be  regarded  as  representing  an  aberrant  branch  of  the  Diplograptidae,  one  of 
the  variety  of  forms  which  are  characteristic  of  the  first  outburst  of  that 
family,  and  which  soon  disappear  again.  Trigonograptus  can  not  be  con¬ 
sidered  a  climacograptid,  though  where,  oy  maceration  or  compression,  the 
thecae  have  slightly  separated,  the  appearance  of  a  climacograptid  is  some¬ 
times  produced. 

Trigonograptus  ensiformis  Hall  sp. 

Plate  17,  figures  1-9 

Retiolites  ensiformis  Hall.  Geol.  Sur.  Can.  decade  2.  1865.  p.lJL4£f, 

pi. 14,  fig. 1-5 

Trigonograptus  ensiformis  Hopkinson  &  Lapworth.  Quar.  Jour.  Geol. 
Soc.  1875.  31:659ff,  pi  34,  %.8a-c 

Trigonograptus  ensiformis  Ami.  Geol.  Sur.  Can.  Rep’t,  ser.  2.  1889. 

v.3,  pt2,  p.H7k 

Trigonograptus  ensiformis  Nicholson.  Geol.  Mag.  ser.  3.  1890.  7:340, 

341,  fig.l,  2 

Trigonograptus  ensiformis  Gurley.  Jour.  Geol.  1896.  4:299 


728 


NEW  YOKE  STATE  MUSEUM 


T  rig  on  og  rapt  us  ensiformis  Elies.  Qnar.  Jour.  Geol.  Soc.  189S.  54:523, 

524,  fig. 34 

Trigonograptus  ensiformis  Ruedemann,  N.  Y.  State  Paleontol.  An.  Rep’t. 

1902.  p.571 

There  occur  in  great  number  .on  the  shales  at  the  dam  in  the  Deep 
kill  section  gigantic  lanceolate  rhabdosomes,  mostly  without  apparent  trace 
of  structure,  which,  as  their  characteristic  outline  and  size  readily  sug¬ 
gest,  belong  to  Hall’s  Quebec  species,  Trigonograptus  ensiformis. 

Description.  Rhabdosome  long,  lanceolate,  reaching  its  maximum  width 
(7  mm  or  more)  about  20  mm  from  the  sicular  end  and  converging  in  a 
like  degree  at  the  antisicular  end.  The  similar  end  provided  with  a  slightly 
geniculate,  bluntly  terminating,  short  appendage ;  antisicular  virgular  extension 
or  nema  not  observed.  Total  length  unknown  ;  fragments  [fig.3]  attaining  a 
length  of  80  mm  and  more,  so  that  the  rhabdosome  may  have  reached  a  size 
of  1  dcm.  Margins  in  most  specimens  perfectly  linear  and  unbroken. 
Thecae  indicated  by  the  thick  interthecal  walls;  alternating,  in  contact 
throughout  their  whole  length,  numbering  10  to  11  in  the  similar  portion 
and,  mostly,  only  8  within  the  space  of  10  mm  in  the  mature  portions. 
The  apertures,  which  are  rarely  well  shown  [fig.7,  9],  are  subquadratic, 
lying  in  one  line  and  obliquely  to  the  axis  of  the  thecae ;  they  are  with¬ 
out  any  apertural  appendages.  The  thecae  form  an  angle  of  about  45°  with 
the  axis  of  the  rhabdosome.  Along  the  latter,  in  somewhat  macerated 
specimens  a  perfectly  straight,  stout  virgula  is  seen  to  pass.  The  test  does 
not  show  any  traces  of  reticulation,  but  is  smooth  and  thick,  and  often 
bordered  by  longitudinal  thickened  lines,  apparently  formed  by  the  confluence 
of  the  lateral  apertural  margins. 

Position  and  localities.  In  graptolite  bed  6  of  the  Deep  kill  section, 
belonging  to  the  zone  with  Diplograptus  dentatus.  The  species 
has  been  also  observed,  though  less  frequently  and  in  smaller  specimens,  in  the 
base  of  this  horizon  at  Mt  Moreno. 

Hall’s  types  came  from  the  Quebec  group  at  Point  Levis.  According  to 
Gurley,  it  occurs  there  in  the  upper  zone,  with  Diplograptus 


GKAPTOLITES  OF  NEW  YORK,  FAIIT  1 


729 


d  e  n  t  a  t  n  s  .  The  same  author  cites  it  in  his  list  from  Arkansas.  Hop- 
kinson  and  Lapworth  identified  a  small,  more  obtusely  pointed  form,  which 
they  obtained  from  the  Lower  Arenig  of  Ramsey  island  in  Wales,  with 
this  species.  The  latter,  if  not  identical,  represents  a  closely  related  smaller 
type.  Typical  specimens  were  collected  and  described  by  IL.  A.  Nicholson 
from  the  Upper  Skiddaw  slates  (Ellergill  beds)  which  are  homotaxial  with 
the  beds  with  Diplograptus  d  e  n  t  a  t  u  s  in  the  Point  Levis  and  Deep 
kill  regions.  Miss  Elies  also  had  typical  material  from  the  same  horizon  of 
the  Skiddaw  slates  for  investigation. 

Remarks.  This  species  was  doubtfully  referred  by  its  author  to 
Retiolites.  When  Nicholson  erected  the  genus  Trigonograptus,  he  assigned 
R  e  t  i  o  1  i  t  e  s  ensif  ormis  to  it,  though  the  genotype  was  described 
as  having  a  zigzag  virgula,  and  this  form  has  a  straight  one. 

It  appears  that  neither  in  Canada  nor  in  England  specimens  of  such 
gigantic  size  were  observed  as  the  fragments  in  the  Deep  kill  beds  must 
have  come  from.  Hall’s  largest  specimen  measured  nearly  2  A  in.  (about 
62  mm),  while  Miss  Elies  had  a  fragment  measuring  38  mm.  The  one  repro¬ 
duced  here  in  figure  3' measures  80  mm. 

Family  climacograptidae  Freeh 
CLIMACOGRAPTUS  Hall.  1865 

This  genus,  which  becomes  so  prominent,  both  in  number  of  species 
and  individuals,  in  the  higher  zones  of  the  Lower  Silurie,  is  repre¬ 
sented  by  but  two  species,  one  of  which,  C .  p ungens,  though  an 
undoubted  Climacograptus,  is  a  very  diminutive  form,  while  the  other, 
C  .  ?  antenna  ri  u  s,  can  be  referred  only  with  doubt  to  climacograptus. 

On  account  of  this  meager  representation  of  the  genus  in  the  lower 
Lower  Silurie,  we  reserve  the  discussion  of  its  characters  for  the  next  memoir, 
in  which  we  shall  be  better  enabled  to  illustrate  them  with  the  aid  of  the 
larger  and  more  typical  Trenton  material. 


730 


NEW  YORK  STATE  MUSEUM 


Climacograptus  pungens  sp.  nov. 

Plate  16,  figures  14-20 

Climacograptus  sp.  nov.  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t. 

1902.  p.571 

The  finding  of  two  small  rhabdosomes,  in  the  Deep  kill  shale  with 
Dip  log  rapt  us  dentatus,  has  proved  the  appearance  of  the  genus 
Climacograptus  at  this  early  date  in  this  region.  Later  on,  numerous 
specimens  of  the  form  here  described  were  found  in  a  still  somewhat  older 
subhorizon  at  Mt  Moreno,  near  Hudson.  As  the  only  other  species  known 
to  occur  so  early,  viz  C.  seharenbergi  Lapworth  [Ellergill  beds  of 
England;  see  Elies,  1898,  p.519],  is  a  distinctly  different  form,  and  the  frag¬ 
ments  can  not  be  readily  assigned  to  any  younger  species,  they  are  here 
described  as  representing  a  new  species. 

Description.  Rhabdosome  small  (length  of  largest  specimen  18  mm, 
but  average  length  only  12  mm)  and  narrow  (1.6  in  one  case,  as  a  rule  not 
over  1 . 3  mm  wide),  of  uniform  width.  Sicular  end  provided  with  two  very 
long  (12  mm  or  more),  extremely  slender  and  flexuous  appendages.  The 
thecae  are  short,  closely  arranged,  numbering  10  to  12  in  10  mm;  the 
apertures  relatively  large,  broadly  oval,  provided  at  their  outer  margin  Avith  a 
short  spine  [pi.  16,  fig.  14].  The  sutural  groove  is  little  distinct,  slightly 
undulating.  The  nemacaulus  relatively  stout  and  long. 

Position  and  localities.  Rare  in  the  horizon  with  'Diplograptus 
dentatus  at  the  Deep  kill ;  common  in  the  same  horizon  at  Mt 
Moreno. 

Pemarlcs.  From  C  .  s  c  harenbergi  this  form  is  readily  distinguished 
by  the  character  of  the  sutural  groove,  which  in  that  species  is  deep  and 
characteristically  deflected  from  side  to  side,  horizontal  grooves  setting  out 
from  the  outer  points  of  each  angulation.  The  long  appendages  and  the 
apertural  spines  are  also  a  feature  not  absented  in  that  species,  which 
besides,  has  a  greater  number  of  thecae  within  a  space  of  10  mm. 


GUA ITOLITES  OF  NEW  YORK.  TART  1 


731 


Climacograptus?  antennarius  Hall  (sp.) 

Plate  16,  figures  21-26 

Climacograptus  antennarius  Hall.  Geol.  Sur.  Can.  decade  2.  1865.  p.112, 

pl.13,  fig.11-13 

Diplograpsus  antennarius  Nicholson.  Quar.  Jour.  Geol.  Soc.  1868. 
24:139 

Cryptograptus?  antennarius  Lapworth.  Ann.  and  Mag.  Nat.  Hist,  ser  5. 
1880.  5:174 

Cryptograptus  antennarius  Gurley.  Jour.  Geol.  1896.  4:299 

Cryptograptus?  antennarius  Elies.  Quar.  Jour.  Geol.  Soc.  1898. 
54:5 19ff,  fig.3 1 

Climacograptus  antennarius  Roemer  &  Freeh.  Lethaea  palaeozoica.  1897. 
1:611 

Cryptograptus  antennarius  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t. 
1902.  p.571 

Description.  Rhabdosome  medium  sized  (about  20  mm),  of  nearly 
uniform  width  (2.7  to  3.5  mm)  ;  provided  with  a  stout  similar  spine  and 
two  long,  slightly  curved,  rigid  lateral  spines,  diverging  at  an  angle  of 
100°  to  110°  and  attaining  a  length  of  about  5  mm.  Sicula  not  distinctly 
observed.  Thecae  closely  arranged  (9  to  11  in  10  mm)  ;  parallel  to  the  axis 
of  the  rhabdosome ;  apertures  transverse  oval  incisions.  Nemacaulus  stout 
and  straight,  its  proximal  extension  relatively  very  long,  measuring  18  nun 
in  one  instance. 

Position  and  localities.  Common  in  the  horizon  with  Diplograptus 
dentatus,  exposed  at  the  dam  of  the  Deep  kill.  Hall’s  types  came 
from  the  Quebec  group  at  Point  Levis  (upper  horizon).  Nicholson  and 
Elies  have  recognized  this  form  among  the  Skiddaw  graptolites,  and  record 
it  as  occurring  at  various  places  in  the  Upper  Skiddaw  slates  ;  Gurley  lists 
it  also  among  the  Arkansas  graptolites. 

Pemarlcs.  The  synonymy  shows  that  this  small  form,  which  by  its 
outline  and  distal  spines  appears  so  well  characterized,  presents  indeed,  con¬ 
siderable  difficulties  to  a  determination  of  its  generic  relations.  While  Hall 
described  it  as  a  Climacograptus,  it  has  subsequently  been  referred  to 
Diplograptus  by  Nicholson,  to  Cryptograptus  by  Lapworth,  Gurley  and 


732 


NEW  YORK  STATE  MUSEUM 


Elies,  and  again  to  Climacograptus  by  Frecb,  who  does  not  recognize 
the  genns  Cryptograptus.  An  inspection  of  the  numerous  specimens  from 
the  Deep  kill  explains  this  uncertainty  ;  for,  while  the  outlines  of  the  rhabdo- 
somes  are  sharply  defined,  they  are  nearly  always  uninterrupted  and  straight, 
and  the  surfaces  of  the  rhabdosomes  are  perfectly  smooth.  The  apertures 
of  but  one  specimen  [fig.22]  could  be  seen  fairly  well  in  the  frontal  aspect, 
and  the  thecae  of  another  in  their  profile  view  [fig.24].  From  these 
observations  I  infer  that  the  thecae  had  the  same  position  as  in  Climaco¬ 
graptus.  Moreover,  the  strong  development  of  the  distal  spines  is  a  char¬ 
acter  most  developed  in  the  later  species  of  Climacograptus,  and,  hence,  to 
some  extent  indicative  of  this  genus.  Yet,  in  its  habit  this  form  is  by  no 
means  a  typical  Climacograptus,  and  for  this  reason  it  is  here  referred 
with  doubt  to  that  genus. 

Lapworth  expressed  his  belief  that  this  species  may  belong  to  his 
genus  Cryptograptus ;  and  the  general  form  of  the  rhabdosoine  and  the  three 
strong  distal  spines  are  characters  certainly  very  similar  to  those  of  the 
genotype  Cryptograptus  tricornis;  but  the  thecae  of  that  form  are 
described  and  figured  as  inclined,  and  so  are  those  of  Cryptograptus 
hopkinsoni,  which,  in  the  profile  view,  remind  one  strongly  of  those 
of  Diplograptus  dentatus. 

The  perpendicularly  projecting  spinules,  observable  according  to  Hall 
along  the  margins  of  the  rhabdosomes  in  some  specimens,  have  not  been 
noticed  in  the  Deep  kill  material. 

RETIOGRAPTUS  Hall.  1865 

Hall  separated  the  genus  Retiograptus  from  Barrande’s  genus  Retio- 
lites,  making  the  species  described  here  the  type  of  the  new  genus  and 
stating  that  the  three  species  'which  he  refers  to  it  “  are  nearly  related  to 
Retiolites  ;  but  the  texture  of  the  specimens  examined,  and  the  arrange¬ 
ment  of  the  parts,  differ  so  much  from  authentic  specimens  of  Retiolites 
geinitzianus,  that  I  have  separated  them  under  the  above  designation.” 
The  author  of  Retiograptus  concedes  that  the  three  species  united  under 
this  generic  designation  present  some  important  points  of  difference, 


GRAPTOLITES  OF  NEW  YORK.  FART  1 


733 


one  from  the  other.  In  fact,  the  two  other  forms  appear  to  represent 
structures  entirely  different  from  that  of  R .  tentaculatus.  No  forms 
fitting  into  the  generic  diagnosis  of  Retiograptus  have  been  found  else¬ 
where.  The  genus  has,  however,  been  emended  by  Freeh  [1897,  p.607], 
who,  asserting  the  similarity  of  its  rhabdosomes  with  those  of  Gothograptus 
and  Retiolites,  sees  the  diagnostic  characters  of  the  genus  in  the  lesser 
development  of  the  reticulate  structure,  which  he  infers  is  only  suggested 
by  a  row  of  hexagonal  meshes  along  the  margin,  in  the  rectangular 
arrangement  of  the  thecae,  the  presence  of  spines  and  the  resistibility  of 
the  virgula.  From  the  aspect  of  some  specimens  of  R .  tentaculatus 
[pi.  16,  fig.  35]  it  is  to  be  inferred  that  the  entire  periderm  was  reticulate  in  one 
of  its  layers  at  least,  and  that  the  marginal  meshes  correspond  to  apertural 
thickenings  such  as  are  also  found  in  Retiolites.  This  would  leave  as  dis¬ 
tinguishing  characters  between  the  two  genera  only  the  rectangular  arrange¬ 
ment  of  the  thecae  and  the  presence  of  short  apertural  spines. 

If  the  thecae  were  placed  perpendicular  and  the  apertures  straight  and 
parallel  to  the  axis  of  the  rliabdosome,  the  genus,  as  represented  by  the 
genotype  here  described  would  not  be  referable  as  a  reticulate  branch  to 
Climacograptus,  where  the  thecae  hold  positions  parallel  to  that  axis  and  the 
apertures  form  more  or  less  transverse  notches  in  the  straight  margin ;  but 
it  should,  in  the  writer’s  opinion,  be  considered  to  represent  an  extreme  form 
of  Diplograptus,  where  the  angle  of  thecal  inclination  has  become  90°, 
approaches  to  which  are  found  in  some  other  species  of  that  genus  and  also 
in  some  of  Retiolites,  as  e.  g.  R .  venosus  from  the  American  Clinton 
beds. 


Retiograptus  tentaculatus  Hall 

Plate  16,  figures  33-35 

Graptolithue  tentaculatus  Hall.  Geol.  Sur.  Can.  Rep’t  for  1857.  p.134 
Reteograptus  tentaculatus  Hall.  Geol.  Sur.  Can.  decade  2.  1865.  p,116f, 

pi. 14,  fig.6-8 

Retiograptus  tentaculatus  Matthew.  Roy.  Soc.  Can.  Proc.  and  Trans. 
1894.  11:114 

Reteograptus  tentaculatus  Gurley.  Jour.  Geol.  1896.  4:299 


734 


NEW  YORK  STATE  MUSEUM 


Reteograptus  tentaculatus  Roemer  &  Freeh .  Lethaea  palaeozoica.  1897. 

Bd  1,  p.fiOS 

Retiograptus  tentaculatus  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t. 

1902.  p.571 

Description,  llhabclosome  small  (maximal  length  about  20  mm),  elongate 
elliptic,  gradually  and  slightly  widening  toward  the  middle,  where  it  attains 
a  width  of  about  4  mm,  and  equally  narrowing  toward  the  antisicular  end. 
Periderm  finely  reticulate,  the  meshes  subcircular  to  subliexagonal.  Sicular 
end  provided  with  two  shorter  straight  and  two  longer  curved  lateral 
spines,  which  assume  a  direction  subparallel  to  the  axis  of  the  rhabdosome. 
Thecae  placed  rectangularly  to  the  virgula,  numbering  10  to  14  in  10  mm, 
each  provided  with  a  stout,  straight  or  slightly  downward  curved  spine  and  a 
ringlike  thickening  of  the  apertural  margin.  Apertures  straight,  parallel  to 
the  axis  of  the  rhabdosome. 

Position  and  localities.  In  the  shale  exposed  at  the  dam  in  the  Deep 
kill  section,  belonging  to  the  zone  with  Dip  log  rapt  us  den  tat  us 
and  in  the  somewhat  older  beds  at  Mt  Moreno  near  Hudson.  Hall’s  material 
came  from  the  same  horizon  at  Point  Levis.  Matthew  referred  a  form  from 
the  division  3  d  of  the  St  John  group  with  doubt  to  this  species.  As  all  the 
other  species  of  3  d  are  those  of  the  Tetragraptus  zone,  it  is  not  likely  that 
R .  tentaculatus  is  present  in  that  horizon. 

Remarks.  Some  of  the  specimens  of  this  species  possess  a  considerable 
similarity  with  Gloss  ogr  apt  us  fimbriatus  Hopkinson,  which  occurs 
in  the  homotaxial  Ellergill  beds  of  the  Upper  Skid  daw  slates ;  they  differ  still 
in  the  smaller  length  of  the  spines  and  smaller  number  of  thecae  within  a 
certain  space. 

In  one  specimen  [fig.35],  which  is  well  preserved  and  which  exhibits  a 
distinct  reticulation,  some  of  the  apertural  spines  are  prolonged  into  chitinous 
filaments,  which,  bending  downward,  unite  with  those  of  the  next  preceding 
thecae  in  a  manner  suggesting  the  marginal  structure  of  Lasiograptus. 
The  latter  structure  according  to  Tornquist  [1890,  t.2,  fig.27]  and  Freeh 
11897,  p.672],  consists  of  the  distal,  coarsely  perforated  portions  of  the 
thecae. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


735 


ADDENDUM 

caryocaris  Salter  and  dawsonia  Nicholson 

Associated  with  the  graptolites  of  the  Deep  kill  and  Normanskill  beds, 
we  have  found  numerous  small  variously  shaped  bodies  which  consist  of  a 
substance  that  is  similar  to,  but  as  a  rule,  more  tenuous  than  that  of  the 
graptolites.  For  one  group  of  these  bodies  the  generic  term,  Caryocaris,  has 
been  proposed  by  Salter  [1863,  p.139],  for  another  that  of  Dawsonia  by 
Nicholson  [1873,  p.139].  The  former  were  considered  crustaceans,  the  latter 
“ovarian  capsules”  (“  grapto-gonophores  ”)  of  graptolites.  Gurley  [1896, 
p.85ff]  has  maintained  that  both  are  graptolites.  As,  at  least,  in  regard  to 
one  group,  the  Dawsonias,  our  material  tends  to  verify  his  observations,  we 
have  appended  here  the  descriptions  of  the  representatives  of  both  groups 
occurring  in  the  lower  graptolite  beds  ;  but  wish  it  understood  that  we  con¬ 
sider  their  taxonomic  position  not  yet  determined. 

The  substance  and  texture  of  the  test  of  all  these  forms  is  one  of  their 
characteristic  features  by  which  they  can  be  readily  recognized.  It  is 
apparently  of  a  chitinous  nature,  but  mostly  thinner  than  that  of  the 
graptolites,  of  less  luster,  possessing  often  a  light  purplish  tint,  also  observed 
by  Etheridge,  Woodward  and  Jones1  in  regard  to  Caryocaris 
wriglitii,  and  above  all  an  extremely  delicate,  irregular  corrugation  or 
wrinkling,  the  wrinkles  often  assuming  the  appearance  of  scales  or  regularly 
overlapping  tiles  [pi.  17,  fig.17].  This  corrugation,  which  is  never  found  so 
strongly  developed  on  the  periderm  of  the  graptolites,  is  an  indication  of 
the  thinness  and  flaccidity  of  the  test  of  the  forms  under  discussion.  It 
often  appears  like  a  shriveling,  but  is  in  most  cases  clearly  superin¬ 
duced  by  the  incipient  and  minute  cleavage  or  slipping  of  the  rock.  Its 
character  is  indicated  on  the  figures,  which  also  show  that  the  wrinkles 
cross  the  specimens  in  no  definite  direction,  but  that  the  latter  depends 
entirely  on  the  accidental  position  of  the  specimens  to  the  cleavage  planes  in 
the  rock. 


xRep’t  of  the  Committee  on  the  Fossil  Phyllopodaof  the  Palaeozoic  Rocks.  1883,  p.7. 


736 


NEW  YORK  STATE  MUSEUM 


The  carbonaceous  film  which  we  find  in  the  shale  is  probably  but  a 
residuum  of  a  somewhat  thicker  and  more  composite  test;  for  we  observe 
that  the  numerous  shells  of  linguloid  and  oboloid  brachiopods  in  the  same 
shales  are  in  exactly  the  same  tenuous  condition.  The  latter  are,  however, 
known  to  have  lost  their  phosphate  of  lime  component.  As  further, 
Salter  reports  that  the  tests  of  Caryocaris  wrightii  are  often 
quite  solid  for  their  size  and  appear  to  have  had  a  good  deal  of  lime  in 
their  composition,  it  is  possible  that  all  these  now  very  tenuous  shells  are 
leached  out  to  a  considerable  degree. 

caryocaris  Salter.  1863 

The  genus  Caryocaris  was  proposed  by  Salter  for  small  chitinous  bodies 
occurring  abundantly  in  the  Skiddaw  slates  and  described  by  him  as 
follows  : 

A  long,  pod-shaped,  bivalved  carapace  (with  distinct  hinge  pits), 
rounded  anteriorly,  subtruncate  behind,  and  with  the  back  and  front  sub¬ 
parallel.  The  surface  is  smooth,  or  with  only  oblique  wrinkles  near  the 
margins,  but  with  no  parallel  lines  of  sculpture.  Body  ? ,  telson  and 
appendages  ? 

All  1  know  of  this  pretty  little  Crustacean,  an  inch  long,  and  rather 
more  than  one  third  of  an  inch  wide,  is  contained  in  the  above  note. 

Only  one  species,  C .  wrightii,  was  described.  In  a  restoration  of 
the  same  the  presence  of  a  short  abdomen,  with  a  lanceolate  telson  and  stylet 
was  suggested.  Dr  Hicks,  in  1876  [Quar.  Jour.  Geol.  Soc.  32:138],  added 
the  description  of  another  species  from  the  Cambric  of  Wales.  Etheridge, 
Woodward  and  Jones  have,  in  the  paper  cited  above,  described  the  genus 
as  one  of  phyllopod  crustaceans  of  the  Palaeozoicum  and  added  that, 
while  they  have  not  observed  the  abdomen,  as  restored  by  Salter,  Mr  Marr 
has  found,  in  association  with  Caryocaris,  “  some  small,  slender  spines  or 
pointed  styles  .  .  .  which  do  not  contradict  Salter’s  ideal  figure.”  They 
also  state  that  the  ventral  and  anterior  margins  are  thickened  with  a 
raised  rim,  while  the  dorsal  margin  has  no  rim,  as  it  has  in  Salter’s 
figure.  The  “  hinge  pits  ”  cited  by  Salter  could  not  be  found  by  these 
authors. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


737 


Dr  Gurley  noticed  in  the  collection  from  the  Beekmantown  shales  of 
Point  Levis,  Canada,  and  the  Upper  Beekmantown  of  Summit  in  Nevada, 
small,  winged  bodies  in  great  number,  which  he  referred  to  this  genus, 
arranging  them  in  three  specific  groups.  One  of  these  he  considered  identical 
with  the  genotype,  C.  wrightii.  Gurley  holds  now  that  what  hitherto 
has  been  described  as  Caryocaris  are  only  appendages,  and  that  the  complete 
body  [text  fig.103]  consists  of  “two  symmetrically  paired  lateral  appendages 
attached  to  the  distal  end  of  a  single  median  proximal 
portion  on  which  [he  believed]  thecae  could  perhaps  be 
traced.”  It  is  stated  at  the  end  of  the  generic  description 
that  “  it  is  needless  to  add  (as  Lapworth  points  out)  that 
it  is  not,  as  Salter  supposed,  a  crustacean,  but  from  its 
resemblance  to  Dawsonia  appears  to  be  a  graptolite.”12 

Our  Deep  kill  specimens  of  Caryocaris  [pl.l7|  fail 
to  show  either  the  more  complicated  structure,  observed 
by  Gurley,  or  anything  suggesting  thecae,  but  appear 
as  nothing  but  pyriform  bodies  truncate  at  one  end  and 
bluntly  acute  at  the  other.  One  margin  of  one  of  the  figured  specimens  [fig.17] 
has  a  distinctly  raised  rim  on  one  side  which  gives  the  impression  of  being  the 
result  of  a  fracture  through  a  part  of  the  test,  folded  on  itself.  Our  largest 
and  best  preserved  specimen  is  7 . 2  mm  long  and  2 . 8  mm  wide.  It  has,  hence, 

1  We  have  not  been  able  to  find  where  Lapworth  has  expressed  this  view,  but 
noticed  that  in  187t>  [Catalogue  of  Western  Scottish  Fossils,  p  7]  Dawsonia  is  still 
cited  among  the  crustaceans  by  this  eminent  authority  on  graptolites. 

2  Jones  and  Woodward  have  figured  in  their  Monograph  of  the  British  Phyllopods 
a  specimen  of  C.  wrightii  [pt  2,  1892,  p.91,  fig.6]  which  they  had  received  from 
Prof.  C.  Malaise  and  which  appears  to  retain  a  trifid  tail  partly  extruded  below  the  nar¬ 
row  extremity.  They  conclude  on  this  evidence  that,  in  this  crustacean,  style  and  stylets 
were  all  three  dagger-shaped.  It  is  obvious  that  the  views  of  the  British  authors  and  of 
Gurley  are  greatly  at  variance ;  and  our  material  consisting  only  of  the  podlike  bodies 
does  not  permit  us  to  select  between  the  conflicting  opinions.  We  suspect,  however, 
that  the  supposed  caudal  appendage  of  Caryocaris  and  the  trifid  bodies  here  assigned  to 
Dawsonia  monodon  Gurley  are  identical. 


Fig.103  Caryocaris 
wrightii  Salter.  From 
the  Upper  lieekmantown 
of  Nevada.  x2  (Copy 
from  Gurley) 


738 


NEW  YORK  STATE  MUSEUM 


about  the  same  dimensions  as  the  lateral  appendages  of  the  forms  referred 
by  Gurley  to  C.  wrightii,  and  is  considerably  smaller  than  the  pod¬ 
like  bodies  described  under  this  name  from  the  Skiddaw  slates.  In  outline 
and  the  position  of  the  raised  rim  it  agrees  best  with  the  appendages  described 
by  Gurley  as  C .  curvilineatus  from  the  Beekmantown  at  Point  Levis, 

and  the  Upper  Beekmantown  of  Nevada.  We  refer  it 
therefore  with  some  doubt  to  the  latter  species. 

In  the  United  States  National  Museum  there  is  a 
small  suite  of  slabs,  collected  by  C.  D.  Walcott  in  1890, 
on  the  Mettanee  river,  J  mile  above  the  North  Granville 
bridge,  in  Washington  county,  N.  Y.  These  slabs  are 
covered  with  rather  faint,  structureless,  carbonaceous 
films,  which,  in  outline  and  size,  are  somewhat  varying 
and  indeterminate,  but  in  general  resemble  flattened 
or  burst  apple  seeds.  In  one  or  two  places  two  of  these  films  are  united 
in  such  a  fashion  as  to  suggest  that  they  originally  belonged  together 
[pi. 17,  fig.16].  On  a  label  written  by  Dr  Gurley,  one  of  the  latter  specimens 
is  sketched,  and  this  is  added,  “resembles  C.  oblong  us  most,  but  more 
rounded  oval.'1  The  material  in  hand  does  not  allow  any  definite  identification 
or  description  and  we  have  been  unable  to  secure  better  specimens  at  the 
original  locality. 

dawsonia  Nicholson 

As  the  material  referable  to  Dawsonia  which  has  been  found  at  the 
Deep  kill  is  considerably  larger  and  of  a  more  varied  nature  than  that  of 
Caryocaris,  it  allows  a  more  positive  identification  and  expression  of  opinion 
on  the  taxonomic  relations  of  these  bodies. 

Nicholson  \loc.  cit .]  proposed  the  name  Dawsonia  for  the  “ovarian 
vesicles 11  of  graptolites  which  he  had  described  in  his  Monograph  of 
British  (x raptolitGS  [pt  1,  p. 71,  fig.4]  and  which  he  later  on1  designated  as 
“  gonangia 11  of  graptolites.  He  described  four  species,  viz  D  .  acuminata, 


ff) 

0 


\©o 

VJL 

Fig.  104  Caryocaris 
ublungus  Gurloy.  Show¬ 
ing  conjoined  lateral  append¬ 
ages.  From  the  Beekman¬ 
town  shales  at  Point  Levis, 
Canada.  x2  (Copy  from 
Gurley) 


1  Nicholson  &  Lvtldeker.  Manual  of  Paleontology.  1889.  1:214. 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


739 


D.  rotunda,  D.  tenuistriata  and  D.  campanulata.  The  first 
three  are  cited  from  the  Point  Levis  shales  of  Quebec,  the  fourth  from  the 
Upper  Llandeilo  of  the  south  of  Scotland.  The  last  species  is  very  common 
in  the  Trenton  (Normanskill)  graptolite  slates  of  New  York  and  Canada  and 
will  be  noticed  in  the  description  of  the  Trenton  graptolite  fauna.  Nicholson’s 
second  and  third  species,  which  are  also  very  common  in  the  Deep  kill  slates, 
are,  without  doubt,  leached  out  shells  of  small  undescribed  brachiopods, 
referable  to  Acrotreta  and  Paterula,  The  first  species,  D.  acuminata, 
which  is  the  genotype,  is  represented  by  long,  oval,  corneous  bodies,  which 
have  one  extremity  prolonged  into  a  long  acuminate  mucro.  The  genus, 
originally  proposed  for  an  agglomeration  of  variously  shaped  bodies,  belong¬ 
ing  to  entirely  different  groups,  should  evidently  be  restricted  to  fossils  of 
similar  form  and  character. 

Nicholson’s  contention  that  these  fossils  were  gonangia  of  graptolites  has 
never  found  any  recognition,  and  this  for  good  reason ;  for,  while  they  are 
found  associated  in  great  numbers  with  the  graptolites  and  only  with  these, 
they  have  never  been  observed  in  direct  attachment  to  any  part  of  the  rhabdo. 
some,  but  are  always  found  entirely  free.  Their  mere  association  with  the 
graptolites  is  no  evidence  of  their  being  a  part  of  the  graptolite  structure ; 
just  as  little  the  minute  brachiopod  shells,1  mostly  of  oboloid  type  and  found 
often  in  immense  numbers  associated  with  graptolites,  would  be  considered  as 
parts  of  graptolites. 

As  these  fossils  have  not  been  considered  to  be  of  graptolitic  nature,  we 
do  not  find  them  cited  in  the  lists  of  graptolites,  as  for  instance  in  those  of  the 
Skiddaw  or  of  the  St  David’s  shales.  Lapworth  mentions  D .  cam¬ 
panulata  in  his  Catalogue  of  the  Western  Scottish  Fossils  [p.7]  ;  but 
among  the  crustaceans.  Ami  [1889,  p.llTk]  cites  three  forms  of  Dawsonia  with 

1  The  brachiopods  of  the  graptolite  shales  are,  from  the  Cambric  shales  to  the  Utica 
epoch,  so  similar  in  all  their  characters  that,  while  belonging  to  dilferent  genera,  they 
probably  furnish  an  excellent  instance  of  adaptation  to  a  definite  mode  of  life  —  per¬ 
haps  a  pseudoplanktonic  existence  by  adhesion  to  floating  seaweeds.  They  will,  at  an 
opportune  time,  be  made  the  subject  of  a  separate  investigation  by  the  writer. 


740 


NEW  YORK  STATE  MUSEUM 


the  graptolites  of  the  St  Lawrence  region.  With  these  exceptions,  these 
extremely  common  fossil  organisms  of  the  graptolite  shale  remained  com¬ 
pletely  unnoticed  till  Dr  Gurley  began  systematically  to  study  the  North 
American  graptolites.  He  recognized  two  species  in  the  Beekmantown  shales 
of  Point  Levis,  Quebec,  both  of  which  are  found  in  the  homotaxial  Deep  kill 
beds. 

In  one  of  them,  D .  t  r  i  d  e  n  s ,  its  author  observed  three  denticles, 
which,  he  states,  “  seem  to  indicate  thecae,  but  from  the  extreme  tenuity  of  the 
film  it  is  not  possible  to  determine  this  point  definitely.”  Our  examples  of  the 
same  species  show  these  same  pointed  denticles  very  distinctly  in  some 
cases  [pi.  17,  fig.19].  While  they  appear  as  nothing  but  incisions  into  the 
margin  of  the  fossil  —  which,  however,  by  their  regularity  and  sharp 
delineation  seem  to  refute  the  supposition  that  they  could  be  a  mere  fring¬ 
ing  out  of  the  margin  due  to  the  cleavage  of  the  rock  —  we  are  able  to 
discern  distinct,  projecting  thecae  in  several  well  preserved  specimens  of 
the  other  species,  D.  monodon  [fig.23].  They  are  also  shown  in  profile 
in  a  fragment  of  the  apical  part  of  the  latter  species  and  exhibit  in  the  frontal 
view  transversally  oval  apertures  [pi.  17,  fig.25]. 

These  observations  suggest  that  at  least  the  two  species  of  Dawsonia 
noted  in  this  place,  were  provided  with  a  small  number  of  thecae.  The  bodies 
described  here  appear  to  represent  the  perfect  organism,  as  they  are  clearly 
and  definitely  bounded  at  both  extremities.  As  colonies,  they  look  very 
different  indeed  from  all  other  graptolite  colonies,  and  they  must,  if  they 
should  be  proved  by  further  investigations  to  be  complete,  be  regarded  as  a 
quite  aberrant  branch  of  the  class  of  graptolites. 

The  carbonaceous  films,  representing  these  two  species  of  Dawsonia, 
have,  above  all,  the  appearance  of  having  originally  belonged  to  bag-shaped 
bodies.  This  impression  is  specially  created  by  wrinkles  which  run  parallel 
to  and  increase  toward  the  major  margins  [comp,  fig.24].  As  these  supposed 
bags  do  not  show  any  indications  of  attachment  at  either  end,  it  is  to 
be  inferred  that  the  colonies  remained  free  during  their  lifetime,  and 
the  major  portion  of  the  bags  may  have  functioned  as  hydrostatic 
apparatus. 


I 


> 


I 

I 

GR A PTOLITES  OF  NEW  YORK,  PART  1  741 

Dawsonia  tridens  Gurley 

Plate  17,  tlgure  18-20 

Dawsonia  tridens  Gurley.  Jour.  Geol.  1896.  4:88,  pl.5,  fig.5 
Dawsonia  tridens  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 

p.556 

Description.  Ilhabdosome  shortly  and  asymmetrically  fusiform  in  out¬ 
line ;  about  3  mm  long  (3.4  mm  maximal  length  observed),  1.1mm  wide,  drawn 
out  at  both  extremities  into  blunt  mucros.  A  median  groove,  which  becomes 
most  distinct  at  the  athecal  extremity,  connects  the  mucros.  On  one  side 
there  are  two  or  three  oblique  incisions  which  produce  acute  denticles  of  the 
appearance  of  thecae.  Other  side  more  convex,  with  entire  margin.  Sub¬ 
stance  chitinous  (?),  thin. 

Position  and  localities.  Common  at  the  Deep  kill  in  graptolite  beds  1 
and  2  of  the  Tetragraptus  horizon.  Gurley  obtained  liis  types  from  the  same 
horizon  at  Point  Levis. 

Remarks.  Our  material  agrees  in  most  particulars  with  the  description 
and  figure  given  by  Dr  Gurley.  AVe  were,  however,  unable  to  discern  the 
“  pustules  ”  observed  by  him  at  the  inner  ends  of  the  incisions ;  but  noticed 
sometimes  a  widening  of  the  incisions  at  this  place  [fig.ISJ.  The  groove, 
described  by  the  same  author,  as  occurring  at  the  blunter  extremity,  crosses 
our  specimens  longitudinally.  As  Gurley  remarks,  this  species  resembles  in 
outline  and  size  most  closely  D.  acuminata  Nicholson.  The  latter, 
however,  has  one  extremity  rounded  and  can  by  this  feature  be  readily 
distinguished. 

Dawsonia  monodon  Gurley 

Plate  17,  figure  21-26 

Dawsonia  monodon  Gurley.  Jour.  Geol.  1896.  4:88,  pl.5,  fig.4 

Dawsonia  monodon  Ruedemann.  N.  Y.  State  Paleontol.  An.  Rep’t.  1902. 

p.554,  556 

Description.  Rhabdosome  elongate  rhomboidal  in  outline;  about  10mm 
long  and  3  mm  wide ;  of  the  two  extremities  of  the  major  axis  one  (proximal 
one  ?)  rounded,  the  other  acutely  tapering ;  the  two  lateral  extremities 
extended  into  shorter,  downwardly  directed  mucros.  The  acutely  tapering 


742 


NEW  YORK  STATE  MUSEUM 


apical  extremity  theciferous,  three  to  four  tubular  thecae,  directed  away  from 
the  apex,  .incliued  at  an  angle  of  about  20°,  four  times  as  long  as  wide,  in 
contact  about  one  half  of  their  length,  outer  margin  slightly  concave,  apertural 
margin  normal  to  the  axis  of  the  theca.  Sicula  not  observed. 

Position  and  localities.  Common  in  graptolite  beds 
1  and  2  of  the  Deep  kill  zone  with  Tetragraptus ;  at  Point 
Levis  in  the  same  horizon. 

Remarks.  The  term,  monodon,  is  a  misnomer,  for  the 
long  apical  tooth  is  flanked  by  two  lateral  teeth.  In  Dr 
Gurley’s  specimen  one  of  these  has,  as  the  figure  indicates, 
been  broken  away,  thus  leading  to  the  misconception. 
The  remaining  lateral  mucro  has  apparently  been  taken  by 
the  author  of  the  species  for  a  denticle,  representing  a 
theca.  Our  material,  however,  demonstrates  [fig.23]  that  the  thecae  are  to 
be  found  on  the  narrow,  tapering  lower  extremity. 

There  extends  on  the  film  a  broad  and  low,  but  well  defined  ridge 
longitudinally  from  the  theciferous  tapering  end  to  near  the  blunt,  upper 
end.  This  appears  to  be  enveloped  by  a  gradually  widening  conical  mantle, 
proceeding  or  suspended  from  the  rounded  upper  end  and  terminating  below 
the  middle,  its  lower  margin  being  produced  into  the  lateral  mucros.  The 
whole  has  the  appearance  of  a  single  theciferous  branch,  extending  the 
whole  length  of  the  organism  and  protruding  at  the  lower  (distal)  end,  the 
upper  (proximal)  portion  of  which  is,  (on  all  sides  ?)  surrounded  by  a  conical 
bag.  As  the  rhabdosome  does  not  show  any  indications  of  having  been 
attached  in  any  way,  it  would  here,  as  in  the  preceding  species,  suggest  itself 
that  the  bag  represents  some  form  of  hydrostatic  apparatus. 

A  difficulty  to  the  understanding  of  this  form  is  presented  by  the 
direction  of  the  thecae  away  from  the  distal  point  or  apex.  This  direction  of 
growth  appears  identical  with  that  in  the  Axonophora,  but  in  the  latter  the 
sicula  is  always  to  be  found  at  the  farthest  ends  of  the  rliabdosomes,  from 
which  the  thecae  then  grow  in  a  backward  direction  toward  the  center 
of  the  colony.  In  the  present  species,  however,  nothing  that  would  be 
comparable  to  a  sicula  is  to  be  found  at  the  supposed  farthest  theciferous  end. 


Fig-.  105  Dawsonia 
monodon  Gurley. 
From  the  13eekmantown 
shales  at  Point  Levis, 
Canada,  xl.5  (Copy  from 
Gurley) 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


743 


SUPPLEMENTARY  NOTES 

Note  i  Several  pamphlets  received  from  Mr  T.  S.  Hall  of  Melbourne, 
when  this  memoir  was  nearly  through  the  press,  have  given  the  writer  the 
first  intimation  of  important  investigations  on  Lower  Siluric  graptolites 
carried  on  by  our  antipodes  since  the  publications  of  McCoy  and  Etheridge 
on  this  subject.  Unfortunately  I  have  even  now  been  unable  to  obtain  all 
desired  literature  in  time  for  this  supplementary  note.  Since,  however,  the 
occurrence  of  our  Beekmantown  graptolites  in  Australia  has,  in  this  memoir, 
been  recorded  only  after  the  identifications  contained  in  the  earlier  papers, 
which,  according  to  Mr  Hall  are  —  owing  to  their  antedating  Lapworth’s 
revision  of  the  British -graptolites  —  in  many  cases  unreliable,  I  append  here 
in  amendment  of  my  oversight  a  list  of  the  American  graptolites  recognized 
by  Hall  and  others  in  Australia  as  well  as  other  facts  of  importance  from 
their  papers  in  regard  to  the  fauna  here  described. 

The  following  list  of  later  Australian  publications,  as  complete  as  I  can 
glean  it  from  Mr  Hall’s  papers,  is  to  be  added  to  “References,”  forming  chapter  1. 


1886  Hector,  James.  Catalogue  New  Zealand  Geological  Exhibits,  Ind.  and  Col. 
Exhibit,  p.82 

1892  Hall,  T.  S.  Proceedings  Royal  Society  of  Victoria,  n.  s.  4,  p.7 

1894  -  6,  p.74 

1895  -  7,  p.55 

1895  Pritchard,  G.  B.  Proceedings  Royal  Society  of  Victoria.  n0  s.  7,  p.30 
1897  Hall,  T.  S.  Proceedings  Royal  Society  of  Victoria,  n.  s.  10  [9  ?],  p.131,  183 

1897  Dun,  W.  S.  Records  of  the  Geological  Survey  New  South  Wales,  5:124 

1898  Hall,  T.  S.  Proceedings  Royal  Society  of  Victoria  n.  s.  10,  p.202 

1899  -  11,  p.164 

1899  -  Geological  Magazine  n.s.  Dec.  4,  6:438 


Mr  Hall  recognizes  four  divisions  in  the  lower  Ordovicic  rocks  of  Victoria. 
1  Lancefield  series ,  which  besides  Australian  species  of  Bryograptus, 
Leptograptus,  Didymograptus,  Tetragraptus,  a  Phyllograptus  ?  and  Dictyo- 
nema  contains  the  following  species  of  the  Northern  Hemisphere. 


Clonograptus  flexilis  J.  Hall 
C.  rigidus  J.  Hall 


C.  rigidus  var.  tenellus  Linna/rs. 


744 


NEW  YORK  STATE  MUSEUM 


2  Bendigo  series.  This  contains  the  following  species1: 


^Didymograptus  bifidus 
D.  cf.  decens  Tornq. 

*D.  gracilis  Tornq. 

*D.  caduceus  Salter 
*Tetragraptus  fruticosus  J.  Hall 
*T.  6erra  Brong. 


*T.  quadribrachiatus  J.  Hall 
*Dichograptus  octobracliiatus  J.  Hall 
*Phyllograptus  typus  J.  Hall 
*Goniograptus  thureaui  McCoy 
G.  macer  T.  S.  Hall 


3  Castlemaine  series.  This  contains : 


*Didymograptus  bifidus  J.  Hall 
D.  murchisoni  Beck  (a  European  form) 
D.  cf.  decens  Tornq.  (a  European  form) 
*D.  caduceus  Salter 
*Tetragraptus  serra  J.  Hall 
*T.  quadribrachiatus  J.  Hall 
T.  projectus  T.  S.  Hall 
*Dichograptus  octobrachiatus  J.  Hall 
*D.  octonarius  J.  Hall 


*Clonograptus  sp. 

*Phyllograptus  typus  J.  Hall 
*P.  angustifolius  J.  Hall 
*Loganograptus  logani  J.  Hall 
Goniograptus  macer  T.  S.  Ball 
Dendrograptus  sp. 

Diplograptus  sp. 

Climacograptus  sp. 

Trigonograptus  sp.  ?  and  other  unidentified 
forms 


4  Darriwill  series.  The  fauna  of  this  series  is  said  to  differ  from  the 
Castlemaine  one  by  the  almost  entire  absence  of  Didymograptus 
caduceus  and  the  appearance  of  Lasiograptus  and  Glossograptus ; 
Trigonograptus  and  several  species  of  Didymograptus  and  Climaco¬ 
graptus  occur,  while  Tetragrapt  us  serra  and  Loganograptus  still 
persist. 

A  comparison  of  these  fossil  lists  with  those  from  New  York  and  Can¬ 
ada  leaves  no  doubt  that  the  general  secpience  of  the  American  and  the 
Victorian  graptolites  is  the  same,  but  as  Mr  Hall  states  “  experience  has 
shown  that  it  is  unsafe  to  push  the  analogy  too  far  and  that’the  only  safe 
method  is  that  of  detailed  stratigraphic  work.”  It  is  added  by  the  same 
author :  “  Thus  we  find  forms  here  associated  which  elsewhere  are  separated 
by  intervening  zones ;  and  on  the  other  hand,  forms  elsewhere  associated 
may  be  here  separated.”  In  this  connection  it  is  now  extremely  interesting 


1  Those  occurring  in  Canada  or  New  York  are  denoted  by  an  asterisk  (*)• 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


745 


to  note  that  the  most  important  differences  between  the  sequence  of  the 
graptolites  of  Australia  and  that  of  the  northern  hemisphere,  pointed  out 
by  Mr  Hall,  are  not  borne  out  by  the  vertical  distribution  of  the  grapto¬ 
lites  observed  in  New  York,  and  the  Australian  and  New  York  graptolite 
ranges  agree  in  these  cases.  Didymograptus  b  i f  i d u s  is  stated  to 
die  Out  in  Australia  long  before  Phyllograptus  typus  has  dis¬ 
appeared,  but  also  at  the  Deep  kill,  where  both  continue  through  grapto¬ 
lite  bed  5,  the  former  passes  its  maximum  frequency  long  before  the  latter. 
In  the  lowest  Ordovicic  rocks  at  Lancefield  in  Victoria  “Clonograptus 
flexilis  and  C.  rigidus  are  found  in  association  with  Bryograptus, 
while  in  Europe  and  America  Byrograptus  is  a  Cambrian  form.”  At  the 
Deep  kill  we  have  found  two  species  of  Bryograptus,  one  in  great  number,  in 
a  horizon  undoubtedly  still  above  that  characterized  by  Clonograptus 
f  1  e  x  i  1  i  s  and  C  .  rigidus.  Loganograptus  in  Australia  does  not  appear 
till  Phyllograptus  typus  and  closely  allied  species  have  become 
extinct.  This  is  probably  exactly  the  case*in  the  graptolite  beds  of  New 
York,  where  entire  specimens  of  Loganograptus  logani  have  only 
been  found  in  the  horizon  with  Diplograptus  dentatus,  though 
detached  branches  found  in  deeper  horizons  have  been  doubtfully  referred  to 
that  species  [ see  p.632],  and  Gurley  also  records  the  form  only  from  the  upper¬ 
most  Levis  horizon. 

Since  the  exact  faunules  of  the  graptolite  zones  at  Point  Levis  in 
Canada  have  not  been  determined  and  Gurley  [1896,  p.294]  for  instance  is 
unable  to  state  the  range  of  Phyllograptus  typus  at  that  renowned 
locality,  the  sequence  furnished  by  the  Deep  kill  section  in  New  York  is 
at  present  to  be  considered  as  representing  that  of  eastern  North  America. 
The  differences  pointed  out  by  Mr  Hall  are  then  perhaps  more  those  between 
the  Australian  and  North  American,  graptolite  fields  on  one  hand 
and  the  European  on  the  other,  or  those  between  the  Pacific  and  Atlantic 
basins. 

There  is  no  doubt  that  Mr  Hall  is  right  in  placing  the  Lancefield 
series  with  its  Clonograptus-Bryograptus  fauna  at  the  base  of  the  Australian 


746 


NEW  YORK  STATE  MUSEUM 


graptolite  beds,  since  our  evidence  goes  to  show  that  also  here  this  fauna 
precedes  the  Tetragraptus-Phyllograptus  fauna.  From  his  statement  that 
Didymograptus  b  i  f  i  d  u  s  is  very  rare  in  the  Bendigo  series  and  “  per¬ 
haps  indicative  of  the  higher  beds  of  the  series”  I  infer  that  in  time 
the  division  line  corresponding  to  that  between  our  Tetragraptus  zone  and 
the  zone  with  Didymograptus  bifidus  will  be  drawn  through  the 
Bendigo  series,  and  likewise  a  division  line  between  the  latter  zone  and  that 
of  Diplograptus  dentatus  may  be  found  in  the  Castlemaine  series, 
and  a  very  exact  correlation  of  the  American  and  Australian  zones  will  thus 
be  attained.  At  any  rate  so  much  is  certain:  that  all  the  American  zones 
of  the  Lower  Ordovicic  are  represented  in  Australia.  The  number  of 
forms  common  to  America  and  Australia,  which  aj>pear  in  Mr  Hall’s  lists,  is 
truly  astonishing  and  will  rather  increase,  I  believe,  as  investigation  proceeds. 

Mr  Hall  adds  to  the  few  Lower  Ordovicic  forms  cited  by  Freeh  [1897J 
from  New  Zealand  Didymograptus  bifidus,  of  which  he  has 
examples  from  Nelson,  N.  Z. 

Note  2  On  page  517  of  this  memoir  allusion  is  made  to  the  description 
of  an  observation  on  the  structure  of  the  central  disk  of  Dichograptus 
octobrachiatus  which  has  been  omitted  in  its  proper  place.  In  the 
example  figured  on  plate  9,  figure  1,  the  central  disk  has  been  split  through 
the  median  plane  in  the  separation  of  the  slabs.  On  one  slab  a  strong  car¬ 
bonaceous  (chitinous)  test  is  shown,  on  the  other  a  calcareous  layer,  which 
rests  on  another  carbonaceous  test  and  clearly  has  segregated  between  the 
two  carbonaceous  tests.  This  calcareous  layer  is  thickest  between  the  branches 
and  thins  out  toward  the  margin  of  the  disk  and  upon  the  branches  without, 
however,  becoming  everywhere  discontinuous  along  the  median  line  of  the 
latter.  The  presence  of  this  intercalated  cake  of  carbonate  of  lime  indicates 
that  there  must  have  existed  either  a  space  open  long  enough  within  the 
central  disk  to  allow  the  segregation  of  the  carbonate  of  lime,  or  at  least  an 
original  plane  of  separation  between  two  tests,  where  the  deposition  of  the 
calcareous  salt  could  take  place.  The  form  of  the  calcareous  layer  is  such  as 
to  suggest  the  presence  of  an  original  open  space  in  the  disk,  but  at  any 
rate  the  occurrence  indicates  the  composition  of  the  central  disk  of  two  tests. 


EXPLANATION  OF  PLATES 


748 


NEW  YORK  STATE  MUSEUM 


PLATE  1 

Genus  dictyonema  Hall 

See  pl.3 

Dictyonema  flabelliforme  Eichwald  (sp.) 

Page  599 

1-19  Astogenetic  growth  stages 

1  Sicula  with  very  long  nema.  x5 

2  Sicula  with  budding  first  theca.  x5 

3  Sicula  and  first  theca  matured,  showing  the  divergence  of  the  latter.  x5 

4  Idem,  from  the  other  side,  showing  the  origin  of  the  first  theca  near  the 

apex  of  the  sicula.  x4£ 

5  Young  colony  with  two  thecae.  x5 

6  Another  view  of  a  hke  growth  stage  in  which  both  thecae  strongly 

diverge.  x5 

7  A  specimen  of  the  same  growth  stage  showing  the  point  of  origin  of  the 

second  theca.  x5 

8  A  young  colony  (rhabdosome)  with  three  thecae,  two  of  which  appear  to 

be  of  composite  nature.  x5 

9  Another  aspect  of  a  like  stage  showing  also  the  composite  nature  of  one  of 

the  thecae.  x5 

10  Young  rhabdosome  with  nema  and  primary  disk.  x5 

11  Young  rhabdosome  in  which  the  first  dichotomy  of  a  branch  has  taken 

place.  x5 

12  Young  rhabdosome  showing  several  bifurcations,  the  further  growth  of 

the  branches  and  the  form  of  the  thecae.  x5 
f  3  A  little  more  advanced  rhabdosome  with  the  first  dissepiment.  x5 

14  Young  colony  seen  from  the  under  or  theciferous  side,  exhibiting  the 

thecal  apertures.  x5 

15  Same  view  of  a  somewhat  older  rhabdosome.  The  aperture  of  the  sicula 

is  seen  in  the  center.  x5 

16  Young  rhabdosome  seen  from  the  upper  side.  x5 

1 7  Same  view  of  a  somewhat  older  colony.  x5 


GRAPTOLITES 


Memoir  7.N.YState  Museum 


Plate  1 


R_  Rue  demaniL  del. 


W.  S  .Barkentin,lith. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


749 


18  Young,  more  advanced  rhabdosome,  compressed  somewhat  obliquely  and 

thereby  showing  the  cruciform  initial  portion  and  the  absence  of  dis¬ 
sepiments  in  the  latter 

19  Same  view  of  a  still  more  advanced  rhabdosome  which  shows  a  somewhat 

abrupt  downward  bending  of  the  branches 

20  Normal  and  approximately  mature  specimen 

21  Fragment  of  a  variety  with  widely  separated  branches  and  dissepiments 

and  closely  arranged  thecae 

22  Fragment  of  the  opposite  extreme  of  variation  with  closely  arranged 

broader  branches  and  dissepiments  (var.  confertum) 

All  specimens  are  from  the  upper  Cambric  Dictyonema  shale  at  Schagh- 
ticoke,  Rensselaer  co.  N.  Y.  The  originals  are  in  the  New  York  State 
Museum. 


750 


NEW  YORK  STATE  MUSEUM 


PLATE  2 

Genus  staurograptus  Emmons 
Staurograptus  dichotomus  Emmons 

Page  614 

1-13  Growth  stages 

1  Sicula  with  nema  and  primary  disk ;  the  latter  shaded  much  too  dark  in 

proportion  to  the  thickness  of  its  test.  x5 

2  Sicula  showing  aperture  and  fragment  of  primary  disk.  x5 

3  Sicula  with  budding  first  theca.  x5 

4  Sicula  with  long  nema,  matured  first  and  budding  second  theca.  x5 

5  Young  rhabdosome  with  fragmentary  primary  disk  and  three  thecae.  x5 

6  Young  rhabdosome  in  which  the  coenosarcal  cavities  have  been  filled  with 

pyrite  and  are  plastically  preserved.  The  point  of  gemmation  of  the 
first  and  second  theca  and  the  formation  of  the  four  secondary  branches 
by  bifurcation  are  distinctly  shown.  The  latter  takes  place  so  close  to 
the  sicula  that  apparently  four  branches  spring  from  the  latter 
[see  fig. 7-10].  x5 

7  Somewhat  obliquely  compressed  young  rhabdosome  which  shows  the  first 

bifurcation  of  a  secondary  branch  and  the  succeeding  thecae  of  the 
branches.  x5 

8  Frontal  view  (or  rhabdosome,  seen  from  below)  of  a  somewhat  younger 

stage  showing  the  aperture  of  the  sicula  in  the  center.  x5 

9  Like  view  of  an  older  growth  stage  in  which  three  of  the  four  secondary 

branches  have  divided  by  dichotomy.  x5 

10  Like  view  of  a  still  more  advanced  stage  in  which  all  four  secondary 

branches  have  again  become  bifurcated  and  one  begins  to  form  branches 
of  the  fourth  order.  The  form  described  by  Emmons  as  Stauro¬ 
graptus  dichotomus  was  a  growth  stage  but  slightly  less 
advanced  than  this.  x5 

1 1  Same  view  of  a  stage  which  exhibits  an  unequal  development  of  the  four 

secondary  branches.  x5 


OR  AP  TOLITE  S 


Memoir  7.  N.Y  State  Museum 


Plate  2 


i 


R.  Ruedemann.  del 


W.S  RarkentinJith. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


751 


12  Young  rhabdosome  with  branches  of  a  higher  order 

13  Still  more  advanced  rhabdosome 

14  Specimen  in  the  mature  condition 

15  Lateral  view  of  a  portion  of  a  mature  branch.  x4^ 

16  Fragment  of  a  colony  exhibiting  an  undulating  character  of  the 

branches 

17  A  laterally  compressed  early  growth  stage,  giving  a  lateral  view  of  the 

early  thecae  and  the  bryograptoid  aspect  of  the  young  colony.  x5 

18  The  same  view  of  a  more  advanced  growth  stage.  x5 

19  The  bryograptoid  aspect  of  an  adolescent  stage.  x5 

20  The  same  aspect  of  a  young,  dense  form 

Staurograptus  dichotomus  var.  apertus  var.  nov. 

21  The  bryograptoid  aspect  of  a  mature,  loosely  branched  form  with  few 

bifurcations 

22  A  variety  with  extreme  scarcity  of  branching 

23  A  mature  specimen  with  moderately  scarce  branching  and  widely  diverg¬ 

ing  branches 

24  A  specimen  with  extremely  widely  divergent  branches  and  scarce 

bifurcation 

All  specimens  are  from  the  upper  Cambric  shales  at  Schaghticoke, 
Rensselaer  co.  N.  Y.  The  originals  are  in  the  New  York  State 
Museum. 


752 


NEW  YORK  STATE  MUSEUM 


PLATE  3 

Genus  desmograptus  Hopkinson 
Desmograptus  intricatus  sp.  nov. 

Page  611 

1  Fragment  of  long  conical  rliabdosome 

2  Nearly  perfect  rliabdosome  showing  at  the  left  side  a  fragment  of  the 

lower  layer  of  the  compressed  cone 

3  Fragmentary  rliabdosome  with  very  small  meshes 

4  Broadly  conical  rliabdosome 

Graptolite  bed  7  of  the  Deep  kill  section.  Figures  1-4  are  incorrectly 
reproduced.  The  meshes  should  be  twice  as  close.  ( See  text  figure  30,  32) 

Desmograptus  cancellatus  Hopkinson 

Page  610 

5  Fragment  of  rhabdosome  with  somewhat  elongate  meshes 

6  Fragment  with  shorter  meshes 

7  Fragment  of  rhabdosome  showing  character  of  proximal  and  distal 

branches  and  meshes 

8  Fragment  with  large  and  broad  meshes 

Graptolite  bed  7  of  the  Deep  kill  section,  Rensselaer  co.  N.  Y. 


Genus  dictyonema  Hall 

See  pi.  1 

Dictyonema  rectilineatum  sp.  nov. 

Page  607 

9  Fragment  of  rhabdosome 

10  Fragment  of  a  more  distal  portion  of  the  rhabdosome  than  shown  in  the 
preceding  figure 

Graptolite  bed  7  of  the  Deep  kill  section 


Dictyonema  furciferum  sp.  nov. 

Page  606 


11  Fragment  of  rhabdosome 

Graptolite  bed  2  of  Deep  kill  section 


ORAPTOLITES 


Memoir  7.N.YState  Museum. 


Plate  3 


RR.et  G.  S  B.  del 


W.  S .  Barkentin-lith. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


753 


Dictyonema  murrayi  Hall 

Page  606 

1 2  Fragment  of  rhabdosome 

Sandy  shales  at  Defreestville,  Rensselaer  co.  N.  Y.  Original  in  United 
States  National  Museum 

Genus  callograptus  Hall 
Callograptus  salteri  Hall 

Page  584 

13  Fragment  of  rhabdosome  showing  the  character  of  the  thecae.  x2 

14  Young  rhabdosome,  exhibiting  a  somewhat  undulating  character  of  the 

branches 

15  Another  young  rhabdosome  with  nemacaulus  and  more  rigid  character  of 

branches 

Graptolite  bed  2  of  the  Deep  kill  section 


754 


NEW  YORK  STATE  MUSEUM 


PLATE  4 

Genus  dendrograptus  Hall 
Dendrograptus  ?  succulentus  sp.  nov. 

Page  581 

1  Large  rhabdosome 

2  Younger  rhabdosome 

3  Fragment  of  rhabdosome  showing  long  undivided  branches 

4  Fragment  of  rhabdosome  showing  terminal  tufts  of  fine  branches 

Graptolite  bed  7  of  the  Deep  kill  section 

Dendrograptus  flexuosus  Hall 

Page  579 

5  Young  rhabdosome 

6  Young  rhabdosome  with  closely  arranged  branches 

Graptolite  bed  2  of  the  Deep  kill  section 

8  Young  rhabdosome  with  basal  disk  or  bulb.  x2 

9  Greater  enlargement  of  the  same  to  show  the  thecal  apertures,  x 

10  Fragment  of  rhabdosome,  showing  the  thecae.  x2 

Graptolite  bed  3  of  the  Deep  kill  section 

Callograptus  cf.  diffusus  Hall 

Page  586 

7  Fragment  of  young  rhabdosome.  x2 

Graptolite  bed  2  of  the  Deep  kill  section 

Dendrograptus  fluitans  sp.  nov. 

Page  582 

11  Rhabdosome.  x2 

12  Further  enlargement  of  branch  of  same.  x7 

Graptolite  bed  2  of  the  Deep  kill  section 

Genus  ptilograptus  Hall 
Ptilograptus  tenuissimus  sp.  nov. 

Page  591 

13  Rhabdosome.  x2 

Graptolite  bed  3  of  the  Deep  kill  section 


G  RAPTOLITKS 


Memoir  7.  N.Y  State  Museum 


Plate  4 


R  R  et  G-.S.B  del. 


W.  S .  Barkentinlith. 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


too 


Ptilograptus  plumosus  Hall 

Page  588 

14  Rhabdosome 

15  Fragment  of  rhabdosome.  x2 

Graptolite  bed  7  of  the  Deep  kill  section 

Ptilograptus  geinitzianus  Hall 

Page  690 

16  Enlargement  of  stem.  x2 

Graptolite  bed  3  of  the  Deep  kill  section 

Genus  strophograptus  gen.  nov. 

Strophograptus  trichomanes  sp.  nov. 

Page  717 

17  Bundle  of  branches 

18-20  Enlargements  of  fragments  of  branches  to  show  character  of  thecae.  x7 
Graptolite  bed  7  of  the  Deep  kill  section 

Genus  bryograptus  Lapworth 

See  pi.  5 

Bryograptus  pusillus  sp.  nov. 

Page  641 

21  Rhabdosome.  x7 

22  Same.  x2 

Graptolite  bed  2  of  the  Deep  kill  section 


756 


NEW  YORK  STATE  MUSEUM 


PLATE  5 

Genus  bryograptus  Lapworth 

See  pi.  4 

Bryograptus  lapworthi  sp.  nov. 

Page  639 

1  Young  rhabdosome  consisting  of  sicula  and  first  two  thecae,  referred  with 

doubt  to  this  species.  Shows  apical  origin  of  first  theca.  x8 

2  Obverse  side  of  young  rhabdosome  with  two  more  thecae.  Shows  also 

apical  origin  of  first  theca.  x8 

3  Rhabdosome  with  four  branches  of  the  second  order.  x2 

4  Rhabdosome  with  five  branches  of  the  second  order 

5  Rhabdosome  with  relatively  small  angle  of  divergence.  x2 

6  Rhabdosome  with  large  angle  of  divergence.  Branches  of  the  second  order 

are  absent.  x2 

7  Rhabdosome  with  symmetric  formation  of  branches  of  the  second 

order.  x2 

8  Specimen  with  very  large  angle  of  divergence.  x2 

9  Very  asymmetric  rhabdosome.  x2 

10  Very  large  specimen  with  very  distal  formation  of  branches  of  the  second 

order.  x2 

11  Enlargement  to  show  the  mode  of  bifurcation.  x8 

12  Young  rhabdosome  with  nema  and  primary  disk.  x7 

Graptolite  bed  2  of  the  Deep  kill  section 

Genus  sigmagraptus  gen.  nov. 

Sigmagraptus  praecursor  sp.  nov. 

Page  702 

13  Rhabdosome.  x2 

14  Sicula  and  first  two  thecae,  presumably  of  this  species.  x7 

Graptolite  bed  3  of  the  Deep  kill  section 


ORAPTOMTES 


Memoir  7.  N.Y State  Museum 


Plate  5 


R.R.et  G.S  B  del 


W.  S .  Barften.tin.lith. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 

Genus  temnograptus  Nicholson 
Temnograptus  noveboracensis  sp.  nov. 

Page  619 

15-18  Branches,  showing  the  dichotomous  mode  of  branching 

19  Central  portion  of  rhabdosome 

20  Distal  branch 

Graptolite  bed  2  of  the  Deep  kill  section 


757 


758 


NEW  YORK  STATE  MUSEUM 


PLATE  6 

Genus  goniograptus  McCoy 

See  pi.  7 

Goniograptus  thureaui  McCoy  var.  postremus  var.  nov. 

Page  621 

1-11  Astogenetic  growth  stages 

1  Young  rhabdosome  consisting  of  sicula  and  first  two  thecae.  x3^ 

2  Young  rhabdosome,  in  which  the  branches  of  the  first  order  have  bifurcated, 

seen  from  the  obverse  side.  x3£ 

3  A  like  growth  stage  seen  from  the  reverse  side.  x3^ 

4  The  next  stage,  in  which  the  eight  branches  of  the  third  order  have 

formed.  x3^ 

5  A  slightly  more  advanced  stage  from  the  reverse  side.  The  brachial 

thecae  of  the  “  denticulate  branches  ”  have  commenced  to  form. 
x3^ 

6  A  similar  growth  stage  seen  from  the  obverse  side.  x3^ 

7  A  further  growth  stage  of  the  rhabdosome,  possessing  the  branches  of  the 

fourth  order  and  short  denticulate  branches.  x2^ 

8  Rhabdosome  in  an  adolescent  growth  stage,  in  which  the  formation  of  the 

branches  has  proceeded  to  that  of  the  eighth  order  and  further  growth 
consists  in  the  lengthening  of  the  denticulate  branches.  x2^ 

9  A  somewhat  more  advanced  growth  stage  showing  the  further  longitudinal 

growth  of  the  branches.  x2^ 

10  A  rhabdosome  in  which  the  formation  of  new  branches  has  ceased,  showing 

well  the  arrangement  of  the  branches  and  the  character  of  the  four 
principal  stems 

11  Mature  rhabdosome 

12  Central  portion  of  a  mature  rhabdosome  retaining  the  alate  central 

disk.  x2 

13  A  fragment  of  a  rhabdosome.  x2 


ORAPTOLITKS 


Memoir  7.  N.YState  Museum 


Plate  6 


R.R.et  G.S.B  del 


W.  S .  Barken.tin,lith. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


759 


14  Rhabdosome  which  is  laterally  compressed,  showing  the  horizontal  disposi¬ 

tion  of  the  branches 

15  A  rhabdosome  showing  some  irregularity  of  branching 

All  the  originals  are  from  graptolite  bed  2  of  the  Deep  kill  section  . 
with  the  exception  of  that  of  figure  2,  which  is  from  graptolite  bed  3. 

Goniograptus  perflexilis  sp.  nov. 

Page  625 
See  pi.  7 

16  Fragment  of  a  rhabdosome 

17  Fragment  of  a  rhabdosome  enlarged  to  show  character  of  the  thecae  and  of 

the  stem  internodes  of  the  principal  stem.  x2 

18  A  further  enlargement  of  a  branch.  x4^ 

The  original  of  figure  17  is  from  graptolite  bed  2  of  the  Deep  kill 
section;  that  of  figures  16  and  18  is  from  the  exposure  at  Mt  Moreno  near 
Hudson  N.  Y. 


760 


NEW  YORK  STATE  MUSEUM 


PLATE  ? 

Genus  goniograptus  McCoy 

See  pi.  G 

Goniograptus  perflexilis  sp.  nov. 

Page  0:25 
See  pi.  6 

1  Young  rhabdosome  showing  branches  of  first  and  second  order.  x2 

2  Young  rhabdosome  witli  branches  of  the  third  order 

3  Young  rhabdosome  with  branches  developed  to  the  fourth  order.  x2 

4  Idem  in  natural  size 

6  Mature  rhabdosome  in  the  usual  confused  state  of  preservation 

7  About  half  of  mature  rhabdosome  with  the  branches'less  confused 

8  Restoration  of  a  mature  rhabdosome  in  spreading  condition 

9  Mature  rhabdosome  laterally  compressed,  retaining  a  proximal,  apparently 

baglike  appendage 

Graptolite  bed  2  of  the  Deep  kill  section 

Goniograptus  geometricus  sp.  nov. 

Pago  627 

5  Half  of  young  rhabdosome 

10  Young  rhabdosome 

1 1  Young  rhabdosome  with  branches  of  the  third  order 

12  Young  rhabdosome  in  a  similar  stage  of  development.  x2 

13  Half  of  a  young  rhabdosome  showing  the  points  of  origin  of  the  denti¬ 

culate  branches.  x2 

14  Similar  fragment  with  longer  denticulate  branches.  x2 

15  A  principal  stem  and  branches  of  a  mature  rhabdosome 

16  Half  grown  rhabdosome  showing  the  four  principal  stems 

17  Two  main  stems  with  the  lateral  branches,  the  latter  showing  the  angles 

of  divergence  in  undistorted  condition 


ORAPTOLITES 


Memoir  7.  N.Y  State  Museum 


Plate  7 


R.R.et  G  S  B  del. 


W.S  .Barken.tin.lith. 


GRAPTOLITES  OF  NEW  YORK.  FART  1 


761 


18  Fragment  of  mature  rhabdosome  showing  the  length  attained  by  the 

branches 

19  Principal  stem  writh  branches,  enlarged  to  show  the  composition  of  the 

stem  internodes  of  one  theca  each.  x2  ■ 

20  Restoration  of  a  mature  rhabdosome  in  undistorted  condition 

Graptolite  bed  3  of  the  Deep  kill  section 


762 


NEW  YORK  STATE  MUSEUM 


PLATE  8 

Genus  dichograptus  Salter 
Dichograptus  octobrachiatus  Hall  (sp.) 

Page  634 
See  pi.  9 

1  Young  rliabdosome 

2,  3  Rkabdosomes  retaining  the  central  disk 

4  Mature  rliabdosome 

5  Fragment  with  central  disk,  showing  the  growth  lines  of  the  latter 

6  Rliabdosome  in  hexad  sta^e  of  reduction 

7  Specimen  still  retaining  a  bifurcation  of  the  fourth  order.  x2 

All  originals  are  from  graptolite  bed  2  of  the  Deep  kill  section  with 
the  exception  of  that  of  figure  6,  which  is  from  graptolite  bed  7. 


GRAPTOLITES 


Memoir  7.  N.Y  State  Museum. 


Plate  8 


R.R.et  Cr  S.B.del. 


W.  S .  BarkentirUith. 


764 


NEW  YORK  STATE  MUSEUM 


PLATE  9 

Genus  dichograptus  Salter 
Dichograptus  octobrachiatus  Hall  (sp.) 

Page  634 
See  pi.  8 

1  Fragmentary  rhabdosomes  with  mature  disks 

Graptohte  bed  3  of  the  Deep  kill  section 

2  Branch  showing  the  thecae  in  their  lateral  aspect 

Graptolite  bed  2  of  the  Deep  kill  section 

Genus  loganograptus  Ilall 
Loganograptus  logani  Hall 

Page  631 

3  Young  rhabdosome  ;  its  branches  drawn  too  thick 

4  Older  rhabdosome 

5  Rhabdosome  with  extremely  tenuous  branches 

6  Central  portion  of  a  rhabdosome 

All  the  originals  are  from  graptolite  bed  7  of  the  Deep  kill  section 

Genus  tetragraptus  Salter 

See  pi.  10, 11, 12 

Tetragraptus  (Etagraptus)  lentus  subgen.  nov.  et  spec.  nov. 

Pa^  e  666 

7  Rhabdosome 

8  The  same  enlarged  to  show  the  character  of  the  sicula  and  thecae. 

9  Another  rhabdosome.  x64 
10  Dorsal  view  of  a  theca.  x64 

Graptolite  bed  3  of  the  Deep  kill  section 


ORAPTOLITE  S 


Memoir  7.  N.Y  State  Museum 


Plate  9 


R  R.et  G  S  B  del. 


W.  S .  Barkentindith. 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


765 


Tetragraptus  fruticosus  Hall  (sp.) 

Page  649 
See  pi.  10 

11  Sicilia  and  first  theca;  pyritized.  x7 

12  Young  rhabdosome  consisting  of  sicula  and  first  two  thecae;  obverse 

side.  x7 

13  Early  growth  stage  of  rhabdosome,  retaining  nema  and  a  portion  of  the 

primary  disk.  x7 

14  Young  rhabdosome  preserved  in  relief;  shows  the  apical  origin  of  the 

first  theca,  the  growth  direction  of  the  first  thecae,  the  sicula  in 
obverse  aspect,  nema  and  primary  disk.  x8 
All  the  originals  are  from  graptolite  bed  2  of  the  Deep  kill  section 
with  the  exception  of  that  of  figure  11  which  is  from  bed  3  and  is  doubt¬ 
fully  referred  to  this  species. 


7G6 


NEW  YORK  STATE  MUSEUM 


PLATE  10 

Genus  tetragraptus  Salter 

See  pi.  9,  11,  12 

Tetragraptus  fruticosus  Hall  (sp.) 

Page  649 
See  pi.  9 

1  Young  rhabdosoine  in  which  the  branches  have  not  yet  commenced  to 
recurve 

2,  3  Specimens  with  narrow,  early  recurving  branches  (var.  tu  biform  is) 

4  A  well  developed  specimen  with  somewhat  later  beginning  geniculation  of 

the  branches.  Shows  broad  nema  (nemacaulus) 

5  Younger  rhabdosoine  with  the  characters  of  var.  tubiformis 

6  A  rhabdosoine  intermediate  between  the  preceding  and  following  forms.  x2 

7  Form  with  very  late  geniculation  of  the  branches  (var.  campanulatus) 

and  broad  nema 

8-10  Specimens  with  extremely  late  or  imperfect  recurving  of  the 
branches 

Originals  are  all  from  graptolite  bed  2  of  the  Deep  kill  section. 


GRAPTOLITKS 


Memoir  7.  N.Y  State  Museum. 


Plate  10 


R.R.et  G-. S.B.del. 


W.  S .  Barkemin.lith. 


-- 


70S 


NEW  YORK  STATE  MUSEUM 


PLATE  11 

Genus  tetragraptus  Salter 

See  pi.  9.  10.  12 

Tetragraptus  quadribrachiatus  Hall  (sp.) 

Page  645 

1  Young  rhabdosome 

Graptolite  bed  2  of  the  Deep  kill  section 

2  A  young  rhabdosome  referred  to  this  species 

Graptolite  bed  7  of  the  Deep  kill  section 

3  Mature  rhabdosome  in  which  one  of  the  branches  has  become  laterally 

compressed,  thus  giving  a  lateral  view  of  the  thecae 
Graptolite  bed  2  of  the  Deep  kill  section 

4  Common  appearance  and  mode  of  preservation  of  the  rhabdosomes  in  the 

shale 

Graptolite  bed  2  of  the  Deep  kill  section 

Tetragraptus  amii  Elies  <fc  Wood 

Page  647  * 

5  Typical  mature  rhabdosome 

0  A  younger  rhabdosome  showing  the  angle  of  divergence  between  the  two 
pairs  of  branches 

7  Young  rhabdosome  compressed  laterally 

Graptolite  bed  2  of  the  Deep  kill  section 

Tetragraptus  serra  Brongniart  (sp.) 

Page  655 

8  Young  rhabdosome.  x2 

9  Average  specimen 

10  Enlargement  of  fragment  of  branch.  x2 
Graptolite  bed  2  of  the  Deep  kill  section 


Plate  11 


GRAPTOLITES 


Memoir  7.  N.Y  State  Museum 


1  8  7  g 


R.R.et  G-.S.B  del. 


W.  S .  Barkentin,  lith.. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


7G9 


Tetragraptus  darkei  sp.  nov. 

Page  652 

11-13  Different  aspects  of  young  rhabdosomes.  x2 

14,  16  A  mature  rhabdosome,  enlarged  (x2)  to  show  more  distinctly  the 
character  of  the  thecae ;  and  the  same  in  natural  size 
15  Young  rhabdosome,  showing  a  rapid  widening  of  the  branches 
Graptolite  bed  3  of  the  Deep  kill  section 

Tetragraptus  pendens  Elies 

Page  653 

17-19  Three  different  aspects  of  mature  rhabdosomes;  figure  18.  xli 
20  Enlargement  of  fragment  of  branch.  x6| 

Graptolite  bed  3  of  the  Deep  kill  section 


770 


NEW  YORK  STATE  MUSEUM 


PLATE  12 

Genus  tetragraptus  Salter 

See  pi.  9, 10,  11 

Tetragraptus  woodi  sp.  nov. 

Page  662  , 

1  Young  rhabdosome,  which  is  so  compressed  that  the  angle  of  divergence  of 
the  branches  of  the  second  order  is  shown 
15,  16  Two  mature  specimens 

Graptolite  bed  2  of  the  Deep  kill  section 

Tetragraptus  similis  Hall  (sp.) 

Page  658 

2,  3  Two  mature  rhabdosomes  laterally  compressed  and  showing  the  common 
mode  of  preservation 

4  A  young  rhabdosome  spread  out  so  that  the  branches  of  the  first  order  are 

shown 

Graptolite  bed  2  of  the  Deep  kill  section 

5  A  mature  rhabdosome  compressed  in  such  a  way  that  two  branches  expose 

their  lateral  aspects  in  full  width  and  two  the  frontal  or  dorsal 
sides 

Graptolite  bed  1  of  the  Deep  kill  section 

6  A  young  rhabdosome  showing  well  the  proximal  part  and  the  rapid 

expansion  of  the  branches.  x2 

7  A  mature  rhabdosome  showing  an  uncommon  mode  of  preservation  by 

which  the  branches  have  become  unnaturally  divergent 

8  Very  early  growth  stage.  Obverse  side,  showing  the  sicula  and  three 

thecae.  x8 

9  A  little  more  advanced  stage  showing  a  long  nema.  Obverse  view.  x8 
10  Young  rhabdosome  showing  nema  and  primary  disk.  Only  the  two 

branches  of  one  side  exposed.  x6| 

Graptolite  bed  2  of  the  Deep  kill  section 


ORAPTOL.ITES 


Memoir  7.  N.Y  State  Museum 


Plate  12 


1  9 

jl  y 


R  R.et  &  S  B. del 


W.  S .  Barkexvtin.lith. 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


771 


Tetragraptus  pygmaeus  sp,  nov. 

Page  664 

11  Young  rhabdosome  showing  the  long,  narrow  sicula  and  the  four  thecae 
from  which  the  four  branches  grow.  x5 
12,  13  Obverse  and  reverse  sides  of  two  approximately  matured  rhabdo- 
somes.  x3. 

14  Mature  rhabdosome,  reverse  side.  But  two  branches  are  exposed.  x7 
Graptolite  bed  2  of  the  Deep  kill  section 

Tetragraptus  taraxacum  sp.  nov. 

Page  663 

17  Early  growth  stage  of  rhabdosome.  Obverse  side.  x8 

18  Mature  rhabdosome.  x2 

19  Mature  rhabdosome  showing  the  rapid  widening  of  the  branches.  x3^ 

20  Young  rhabdosome,  reverse  side,  further  enlarged  to  show  the  point  of 

origin  of  the  first  theca  and  the  bifurcations.  x7 

21  Mature  rhabdosome  showing  maximal  length  of  branches  observed. 

x2 

22  The  original  of  figure  19  in  natural  size 

23  Rhabdosome  showing  the  curvature  of  the  branches.  x2 

24  Young  rhabdosome  showing  the  slender  form  of  the  proximal  thecae. 

x7 

25  A  lateral  pair  of  branches  retaining  their  original  angle  of  divergence. 

x7 

26  Another  pair  of  lateral  branches  compressed  in  different  directions.  They 

show  distinctly  the  outline  of  the  thecae.  x7£ 

Graptolite  bed  2  of  the  Deep  kill  section 


NEW  YORK  STATE  MUSEUM 


772 


PLATE  13 

Genus  didymograptus  McCoy 

See  pi.  14,  15 

Didymograptus  nitidus  Hall  (sp) 

Page  671 
See  pi.  14,  fig.  5,  6 

1  Large  rhabdosome 

2  Branch,  obliquely  compressed 

3  Typical  specimen 

4  Rhabdosome  with  slightly  declined  branches 

Graptolite  bed  2  of  the  Deep  kill  section 

Didymograptus  nitidus  Hall,  var.  grandis  var.  nov 

Page  674 

5  Most  perfect  specimen  observed 

Graptolite  bed  2  of  the  Deep  kill  section 

Didymograptus  tornquisti  sp.  nov. 

Page  688 

6  Type  specimen 

7  Same,  xlf,  to  show  more  distinctly  the  character  of  the  thecae 

Graptolite  bed  3  of  the  Deep  kill  section 

Didymograptus  patulus  Hall  (sp.) 

Page  674 
See  pi.  14 

8  Young  typical  specimen 

9  Nearly  mature  specimen  with  central  disk 

Graptolite  bed  2  of  the  Deep  kill  section 


OR  APTOLITE  S 


Memoir  7.  N  Y  State  Museum 


Plate  13 


R.R.et  G.S.B.del. 


W.  S .  Barkentin.,1 1  th. 


GIUPTOLITES  OF  NEW  YORK.  FART  1 


Didymograptus  nicholsoni  Lapworth,  var.  planus  Elies  &  Wood 

Page  686 

10  Imperfect  specimen  with  slightly  reclined  branches  in  the  compressed  state. 

Reverse  side.  x2 

11  Typical  rhabdosome.  xlt 

12  Youim  rhabdosome.  Obverse  side.  x2 

O  " 

13  Specimen  showing  distinctly  the  origin  of  first  theca.  x2 

14  Same  in  natural  size 

Graptolite  bed  2  of  the  Deep  kill  section 

Didymograptus  acutidens  Lapworth 

Page  683 

15  Characteristic  rhabdosome.  xly^ 

Graptolite  bed  2  of  the  Deep  kill  section 

Didymograptus  cuspidatus  sp.  liov. 

Page  684 

1G  Sole  rhabdosome  observed 

Ash  hill  quarry  at  Mt  Moreno,  Columbia  co.  N.  Y. 

Didymograptus  extensus  Hall  (sp.) 

Page  668 
See  pi.  14 

17,  18  Constrictiform  appearance 

Graptolite  bed  2  of  the  Deep  kill  section 


774 


NEW  YORK  STATE  MUSEUM 


PLATE  14 

Genus  didymograptus  McCoy 

See  pi.  13,  15 

Didymograptus  extensus  Hall  (sp.) 

Page  668 
See  pi.  13 

1,  2  Rliabdosomes  showing  the  large  size  attained  by  this  species 
Graptolite  bed  2  of  the  Deep  kill  section 
3,  4  Young  rliabdosomes  with  primary  disks.  The  disks  are  shaded  too 
dark.  x2 

Graptolite  bed  1  of  the  Deep  kill  section 

Didymograptus  nitidus  Hall  (sp.) 

Page  671 
See  pi.  18 

5-6  Young  rkabdosomes  with  primary  disks.  The  disks  are  shaded  too 
dark.  x2 

Graptolite  bed  1  of  the  Deep  kill  section 

Didymograptus  patulus  Hall  (sp.) 

Page  674 
See  pi.  13 

7  Young  rhabdosome  with  fragmentary  primary  disk.  x2 
Graptolite  bed  1  of  the  Deep  kill  section 

Didymograptus  filiformis  Tullberg 

Page  686 

8-11  Various  aspects  of  young  rhabdosomes.  x2 
Graptolite  bed  2  of  the  Deep  kill  section 

12  Mature  specimen 

Graptolite  bed  1  of  the  Deep  kill  section 

13  Rhabdosome 

Ash  hill  quarry,  Mt  Moreno,  Columbia  oo.  N.  Y. 

14  Young  rhabdosome ;  obverse  side,  x6£,  to  show  character  of  sicula  and 

thecae 

Graptolite  bed  2  of  the  Deep  kill  section 


GRAPTOLITE  S 


R.Ret  G.SB.del. 


W.S.  BarkentirUith. 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


t  ro 


Didymograptus  gracilis  Tornquist 

Page  679 

15,  16  Mature  rhabdosomes 

17  Obverse  side  of  rhabdosome.  x2 

Graptolite  bed  8  of  the  Deep  kill  section 

18  Relatively  large  specimen 

Ash  hill  quarry,  Mt  Moreno,  Columbia  co.  N.  Y. 

19  Distal  portion  of  branch  with  extremely  slender  thecae.  x6£ 

20  Another  similar  fragment.  x8 

21  Enlargement  (x8)  of  proximal  portion  of  rhabdosome,  to  show  sicula  and 

proximal  thecae 

Graptolite  bed  8  of  the  Deep  kill  section 

Didymograptus  ellesi  sp.  nov. 

Page  682 

22,  23  Typical  rhabdosomes 

24  Rhabdosome.  x2 

Graptolite  bed  3  of  the  Deep  kill  section 

Didymograptus  similis  Hall  (sp.) 

Page  677 

25  Typical  specimen 

Graptolite  bed  3  of  the  Deep  kill  section 

26  Proximal  portion  of  rhabdosome 

Ash  hill  quarry,  Mt  Moreno,  Columbia  co.  N.  Y. 

27  Fragment  of  large  rhabdosome,  referred  to  this  species 

28  Proximal  portion  of  rhabdosome.  Obverse  side.  x2 

29  Young  rhabdosome.  x2 

Graptolite  bed  3  of  Deep  kill  section 

Didymograptus  spinosus  sp.  nov. 

Page  688 

30  Largest  specimen  observed 

31  Enlargement  (x5)  of  proximal  portion  to  show  sicula,  thecae  and 

spines 

32  Young  i’h abdosome 

Ash  hill  quarry,  Mt  Moreno,  Columbia  co.  N.  Y. 


776 


NEW  YORK  STATE  MUSEUM 


PLATE  15 

Genus  didymograptus  McCoy 

See  pi.  13, 14 

Didymograptus  bifidus  Hall  (sp.) 

Page  689 

1  Typical  specimen.  x2 

2  Smaller  rhabdosome 

3  One  of  the  largest  and  most  complete  rhabdosomes  observed.  x2 

Graptolite  bed  3  of  the  Deep  kill  section 

Didymograptus  nanus  Lapworth 

Page  692 

4  Mature  rhabdosome 

5  Proximal  part  of  a  rhabdosome.  x5^ 

Graptolite  bed  3  of  the  Deep  kill  section 

Didymograptus  caduceus  Salter  emend.  Ruedemann 

Page  693 

6,  7  Two  specimens  showing  the  prevailing  expression  of  the  form  at  the 
Deep  kill.  Natural  size 
Graptolite  bed  2  of  the  Deep  kill  section 

Didymograptus  caduceus  Salter  nanus  mut.  nov. 

Page  698 

8,  9  Two  typical  rhabdosomes.  x2 

Graptolite  bed  (5  of  the  Deep  kill  section 

Didymograptus  forcipiformis  sp.  nov. 

Page  699 

10  Typical  rhabdosome 

11  Young  rhabdosome 

12  Branch  of  a  long  and  thin  branched  rhabdosome 

13  Specimen  showing  the  large  angle  of  divergence  of  the  branches 

Ash  hill  quarry,  Mt  Moreno,  Columbia  co.  N.  Y. 


GRAPTOLITE  S 


Memoir  7.N.Y. State  Museum  Plate  15 


R.R.et  G.S.B.del. 


W.  S .  Barkentin.lith . 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


777 


Didymograptus  incertus  sp.  nov. 

Page  700 

14  Single  specimen  observed 

Graptolite  bed  7  of  tbe  Deep  kill  section 

Genns  phyllograptus  Hall 
Phyllograptus  ilicifolius  Hall 

Page  706 

15  Specimen  possessing  the  normal  expression  of  the  species.  x2 

16  Broad  rhabdosome.  The  thecae  are  less  curving  in  the  original  than  in  the 

figure 

17,  18  Two  forms  with  different  positions  of  the  broadest  portions  of  the 
rhabdosomes 

19,  20  Very  narrow  forms 

21  Enlargement  of  the  apertures  of  thecae.  x5 

22  Young  rhabdosome  showing  the  sicula.  x5 

The  originals  are  from  graptolite  bed  2  of  Deep  kill  section  with 
the  exception  of  that  of  figure  18,  which  is  from  graptolite  bed  3. 

Phyllograptus  anna  Hall 

Page  714 

23  Specimen  with  distinct  sicular  spine.  The  direction  of  the  thecae  on  the 

left  side  has  been  incorrectly  traced. 

24,  25  Rhabdosomes  showing  the  prevailing  broadly  truncate  outline  of  the 
antisicular  end.  In  figure  24  it  is  not  quite  correctly  traced  by  the 
lithographer. 

26  A  relatively  large  and  slender  rhabdosome.  The  outline  and  the  anti¬ 
sicular  end  have  been  incorrectly  traced.  The  original  is  narrower  and 
its  margins  less  abruptly  converging  at  the  antisicular  end. 

Graptolite  bed  5  of  the  Deep  kill  section 


778 


NEW  YORK  STATE  MUSEUM 


27  An  enlargement  (x2)  to  show  more  distinctly,  the  direction  of  the  thecae 
The  curvature  of  the  thecae  is  more  uniform  on  the  right  side  than 
it  is  traced  in  the  figure,  and  the  macros  are  lancet-shaped. 

Top  of  graptolite  bed  2  of  the  Deep  kill  section 
28-30  Specimens  showing  the  dwarfed  and  phvlogerontic  condition  of  the 
species  at  the  disappearance  of  the  genus  in  the  horizon  with 
Diplograptus  dentatus  ( P .  anna.  mut.  ultimus). 
Figure  28  in  natural  size,  the  original  from  the  Ash  hill  quarry, 
Mt  Moreno,  Columbia  co.  N.  Y.;  figures  29  and  30,  x2,  the  originals 
from  graptolite  bed  0  of  the  Deep  kill  section.  In  figure  29  the 
lithographer  has  left  out  the  last  thecae  at  the  sicular  end. 

Phyllograptus  angustifolius 

Page  711 

31  Specimen  showing  the  common  expression  of  the  species  at  the  Deep  kill 

section  but  incorrectly  traced. 

Graptolite  bed  6  of  the  Deep  kill  section 

32  A  very  narrow'  form 

Graptolite  bed  2  of  the  Deep  kill  section 

33  Specimen  from  graptolite  bed  5.  x2^.  The  thecal  walls  have  been 

reproduced  incorrectly  by  the  lithographer.  They  are  nearly  straight 
in  the  original. 

34  Fragment  of  young  rhabdosome  showing  the  growing  end.  x2 

Graptolite  bed  6  of  the  Deep  kill  section 

Phyllograptus  typus  Hall 

Page  708 

35-37  Specimens  showing  the  variation  in  the  outline  of  the  rhabdosome 
Graptolite  bed  3  of  the  Deep  kill  section 


GRAPTOLITES  OF  NEW  YORK.  PART  1 


771) 


PLATE  16 

Genus  diplograptus  McCoy 

See  pi.  17 

Diplograptus  laxus  sp.  nov. 

Page  722 

1  Typical  rhabdosome 

2,  3  Rhabdosomes  with  inflated  nemacaulus 

Ashhill  quarry,  Mt  Moreno,  Columbia  co.  N.  Y. 

4  Two  specimens  frdm  graptolite  bed  7  of  the  Deep  kill  section 

5  Enlargement  (x44)  to  show  the  character  of  the  thecae  and  the  sicular 

end 

6-8  Specimens  which  have  a  very  lax  or  loose  appearance.  This  is  the  pre¬ 
vailing  appearance  of  the  species  at  the  Deep  kill.  x2 
Graptolite  bed  7  of  the  Deep  kill  section 
9,  10  Natural  size  drawing  and  enlargement  (x2)  of  a  relatively  long  rhabdo¬ 
some  of  more  compact  appearance 
Graptolite  bed  7  of  the  Deep  kill  section 

Diplograptus  longicaudatus  sp.  nov. 

Page  723 

11  Single  specimen  observed.  x2 

Graptolite  bed  7  of  the  Deep  kill  section 

Diplograptus  inutilis  Hall 

Page  721 

12  Nearly  perfect  rhabdosome 

1 3  Enlargement  (x2)  of  a  fragment  to  show  the  character  of  the  thecae 

Graptolite  bed  7  of  the  Deep  kill  section 


780 


NEW  YORK  STATE  MUSEUM 


Genus  climacograptus  Hall 
Climacograptus  pungens  sp.  nov. 

Page  730 

1 4  Rhabdosome  (x4)  showing  typical  climacograptid  aspect  and  the  apertural 

spines  of  the  thecae 

15  Relatively  long  specimen 

16  Specimen  of  average  size 

17  Rhabdosome  showing  long  filiform  processes  of  the  sicular  end 

Originals  of  figures  14  to  17  from  Ash  hill  quarry,  Mt  Moreno, 
Columbia  co.  N.  Y. 

18  Specimen  with  the  distinct  thecal  form  of  a  Climacograptus.  x2 

Graptolite  bed  7  of  the  Deep  kill  section 

19  Rhabdosome  with  a  different  aspect  of  the  thecae.  x5 

Ash  hill  quarry,  Mt  Moreno,  Columbia  co.  N.  Y. 

20  Rhabdosome  with  long,  stout  sicular  spines.  x7 

Graptolite  bed  7  of  the  Deep  kill  section 

Climacograptus?  (Cryptograptus)  antennarius  Hall 

Page  731 

21-23  Frontal  views  of  rhabdosomes  showing  the  long  nemacaulus  and  long 
spines  of  the  sicular  end 

24  Specimen  showing  the  form  of  the  thecae  in  the  antisicular  portion 

25  Rhabdosomes  showing  the  thecal  aperture  and  character  of  the  sicular 

end.  x2 

26  Rhabdosome  showing  apertural  spines 

Graptolite  bed  7  of  the  Deep  kill  section 


GRAPTOLITE  S 


Memoir  7  N .Y.  State  Museum  Plate  16 


R.R.et  G.S.B.del. 


W.  S .  Ba  rkentin.l  n  h . 


GRAPTOLITES  OF  NEW  YORK,  PART  1 


781 


Genus  glossograptus  Emmons,  Lapworth  emend. 

Glossograptus  hystrix  sp.  nov. 

Page  724 

27  Rhabdosome.  x7 

28-29  Specimens  showing  the  multispinous  character  of  the  rhabdosome.  x2 
Graptolite  bed  7  of  the  Deep  kill  section 

Glossograptus  echinatus  sp.  nov. 

Page  725 

30,  31  Small  rhabdosomes  showing  the  distribution  of  the  spines 
32  Nearly  perfect  rhabdosome 

Graptolite  bed  7  of  the  Deep  kill  section 

Genus  retiograptus  Hall 
Retiograptus  tentaculatus  Hall 

Page  733 

33,  34  Rhabdosomes  showing  the  prevalent  expression  of  the  form  in  the  Deep 
kill  beds.  x2 

35  Specimen  showing  the  extrathecal  meshes.  x2 
Graptolite  bed  7  of  the  Deep  kill  section 


782 


NEW  YORK  STATE  MUSEUM 


PLATE  17 

Genus  trigonograptus  Nicholson 
Trigonograptus  ensiformis  Hall  (sp.) 

Page  727 

1  Very  young  rkabdosome 

2  A  more  advanced  growth  stage 

Ash  hill  quarry,  Mt  Moreno,  Columbia  co.  N.  Y. 

3  Largest  specimen  observed 

4,  5  Fragments  of  rhabdosomes  showing  the  thecal  Avails 

6  Rhabdosome  Avhich  shows  the  thecal  apertures 

7  Fragment  of  another  rhabdosome  Avhich  shows  the  thecal  apertures 

8  Nearly  complete  rhabdosome  in  Avhich  the  process  of  the  sicular  end  is 

retained 

9  Rhabdosome  in  which  the  direction  of  the  apertural  margins  in  relation  to 

the  axis  of  the  thecae  is  shoivn.  x2 
Graptolite  bed  7  of  the  Deep  Fill  section 

Genus  diplograptus  McCoy 

See  pi.  16 

Diplograptus  dentatus  Brongniart  (sp.) 

Page  719  • 

10,  11  Rhabdosomes  of  typical  appearance  and  dimensions 
Ash  hill  quarry,  Mt  Moreno,  Columbia  co.  N.  Y-. 

12  Frontal  aspect  of  a  rhabdosome 

Graptolite  bed  7  of  the  Deep  kill  section 

13  A  young  rhabdosome  retaining  the  long  similar  spine 

Ash  hill  quarry,  Mt  Moreno,  Columbia  co.  N.  Y. 

Genus  caryocaris  Salter 
Caryocaris  cf.  oblongus  Gurley 

Page  738 

14-16  Three  of  the  most  common  aspects  of  the  organism 

Loiver  Cham  plainic  beds  at  the  Mettanee  river,  east  of  North 
Granville,  Washington  co.  N.  Y. 


OR  APTOUTE  S 


Memoir  7  N  Y  State  Museum 


Plate  17 


R.R.et  G.S.B.del. 


W.  S .  Barkentin.,1  it  h . 


< SHAI’TOLITES  OF  NEW  YORK,  PART  1 


783 


Caryocaris  cf.  curvilineatus  Gurley 

Page  738 

17  Prevailing  aspect  of  the  bodies  at  the  Deep  kill  section,  referred  to  this 

species.  x6£ 

Graptolite  bed  1  of  the  Deep  kill  section 

Genus  dawsonia  Nicholson 
Dawsonia  tridens  Gurley 

Page  741 

18  Specimen  showing  incisions  suggestive  of  thecae  and  a  longitudinal  axis. 

x7 

19  A  similar  specimen  with  more  distinct  denticles.  x6 

Graptolite  bed  2  of  the  Deep  kill  section 

20  A  specimen  showing  two  thecoid  tubes.  x7 

Graptolite  bed  1  of  the  Deep  kill  section 

Dawsonia  monodon  Gurley 

Page  741 

21  Complete  specimen  stowing  a  long  median  and  two  lateral  appendages. 

x2 

22  A  smaller  specimen  with  less  developed  lateral  appendages.  x6^ 

23  A  further  enlargement  of  the  original  of  figure  21  (x64)  to  show  more 

distinctly  the  thecal  tubes  of  the  middle  appendages 

24  A  specimen  with  strongly  developed  narrow,  lateral  appendages.  x8 

Graptolite  bed  1  of  the  Deep  kill  section 

25  Frontal  view  of  a  middle  appendage  showing  four  apertures.  x7 

Graptolite  bed  3  of  the  Deep  kill  section 
2f)  A  specimen  with  broad  median  and  short  lateral  appendages.  x6^ 
Graptolite  bed  1  of  the  Deep  kill  section 


INDEX 


Page  numbers  referring  to  descriptions  of  fossils  are  printed  in  black  face  type. 


Acrotreta,  739. 

Actinozoa,  532. 

Aglaophenia,  588. 

Allman,  G.  J.,  cited,  461,  474,  477,  524, 
544,  574,  575. 

America,  graptolite  beds,  488. 

Ami,  H.  M.,  cited,  463,  471,  472,  490,  580, 
585,  589,  621,  623,  633,  651,  656,  660, 
669,  672,  690,  710,  713,  715,  739. 

Amphigraptus,  544,  571,  701. 

Anthozoa,  577. 

Antisicular  end  of  rhabdosome,  484„ 

Antisiculaseite,  484. 

Apertural  margin,  486. 

Apertural  spine,  486. 

Aperture,  486. 

Ardennes,  graptolite  fauna,  following 
p.503. 

Arenig,  graptolite  fauna,  505,  507,651,687, 
following  p.503 ;  lower,  580,  587,  610, 
669,  729;  middle,  580,  585,  610,  673, 
675 ;  upper,  675,  690,  693,  720. 

Arkansas,  graptolite  fauna,  505,  507,  656, 
715,  720,  729,  731,  following  p.503. 

Arme,  484. 

Australia,  graptolite  fauna,  471,  488,  503, 
505,  507,  621,  633,  651,  660,  743-46,  fob 
lowing  p.503.  See  also  Victoria. 

Axonolipa,  487,  488,  514,  515,  516,  518,  519, 
522,  523,  526,  527,  529,  535,  536,  537,  539, 
546,  547,  548,  570,  571,  573,  577,  612-718 ; 
synoptic  table  of  range  of  genera,  508; 
connection  with  Axonophora,  550. 


Axonophora,  483,  487,  488,  499,  514,  515, 
518,  525,  526,  528,  529,  530,  535,  536,  539, 
546,  547,  548,  551,  552,  553,  570,  571,  572, 
574,  575,  718-34;  synoptic  table  of  range 
of  genera,  508;  connection  with  Axo¬ 
nolipa,  550. 

Azygograptus,  536,  568,  624. 
lapworthi,  555. 
suecicus,  555. 

Ballantrae,  Scotland,  graptolite  fauna,  646, 
669,  687. 

Barrande,  J.,  cited,  459,  467,  468,  469,  472, 
479,  484. 

Barrois,  C.,  cited,  464,  471,  495,  647,  657, 
673,  691. 

Basal  cyst,  488. 

Beck,  cited,  467. 

Beekmantown  beds,  585,  611,  715,  737,  738, 
740,  folloimng  p.503. 

Belgium,  graptolite  fauna,  505,  507,  602, 
636.  637,  following  p.503 ;  Dictyonema 
zone,  492 ;  Tetragraptus  zone,  495.  See 
also  Huy-Statte. 

Bellerophon  oehlerti,  691. 

Bendigo  series,  744,  746. 

Billings,  cited,  470,  495,  589,  651,  656,  710, 
following  p.503. 

Bohemia,  graptolite  fauna,  467,  469,  470, 
471,  477,  489,  502,  505,  507,  660,  691, 
folloimng  p.503 ;  St  Anne  zone,  498. 

Bornholm,  graptolite  fauna.  602,  following 
p.503 ;  Dictyonema  zone,  492. 


NEW  YORK  STATE  ME SEEM 


Boutoury,  graptolite  fauna,  657,  673,  691. 
Brackiopods  of  the  graptolite  shales,  739. 
Branches,  484 ;  terms  for  characteristic 
positions,  485. 

British  Columbia,  graptolite  fauna,  fol¬ 
lowing  p.503. 

Brittany,  graptolites,  471. 

Brogger,  W.  C.,  cited,  462,  471,  492,  592, 
593,  605,  636,  647,  651,  657,  660,  669,  676, 
687,  691,  693,  710,  713. 

Bromell,  M.  v.,  cited,  459,  466. 

Brongniart,  A.,  cited,  459,  466. 
Bryograptus,  492,  495,  508,  531,  533,  537, 
549,  554,  555,  562,  563,  566,  567,  568, 
571,  573,  616,  638-39,  743,  745;  grap¬ 
tolites  derived  from,  555. 
sp.,  562. 
sp.  nov.,  639. 
callavei,  555,  640. 
divergens,  640. 

fruticosus,  see  Tetragraptus  (Bryograp 
tus?)  fruticosus. 
kjerulfi,  638,  640,  641,  642. 
lapworthi  sp.  nov.,  504-5,  557,  558,  560, 
561,  573,  638,  639-41,  682,  683,  684. 
explanation  of  plate,  756. 
figure,  639. 
lentus,  614. 

?  multiramosus,  600. 
patens,  614. 

pusillus  sp.  nov ._,  504-5,  573,  639,  641-42. 

explanation  of  plate,  755. 
ramosus,  640. 

var.  cumbrensis,  555,  556,  559,  639. 

Cabrieres,  graptolite  fauna,  505,  507,  647, 
following  p.503. 


Callograptus,  469,  495,  503,  508,  537,  571, 
572,  583-84,  610;  phylogenetic  rela¬ 
tions  of  genera,  553. 
cf.  diffusus,  504-5,  572,  586-87. 
explanation  of  plate,  754. 
figure,  587. 
elegans.  5S5.  586. 
radicans.  586. 
salteri,  504-5,  572,  584^86. 
explanation  of  plate.  753. 
figures,  585. 

Calycles,  485. 

Canada,  graptolite  fauna,  468,  472,  492, 
503,  585,  589,  601,  602,  633,  673,  678, 
739;  graptolite  zones,  correlation  table, 
following  p.503;  Tetragraptus  zone,  495. 
*SYee  also  Point  Levis;  St  Anne  beds. 

Canal  comrnun,  486. 

Canal  in  the  Graptoloidea,  486. 

Caradoc  shales,  following  p.503. 

Carruthers,  W.,  cited,  460,  470,  477,  574. 

Caryocaris,  495,  508,  574,  735-38. 
cf.  curvilineatus,  506-7,  574,  738. 

explanation  of  plate,  783. 
oblongus,  738. 
explanation  of  plate,  782. 
figure,  738. 

wrigktii,  735,  736,  737,  738. 
figure,  737. 

Castlemaine  series,  744,  746. 

Cells,  485. 
j  Cellules,  485. 

Central  disk,  487. 

Cepkalograptus,  514. 

Ceratopyge  limestone,  495. 

Champlainic  shales,  upper,  722. 

Chaudifcre  river,  graptolite  fauna,  715. 

Chazy  limestone,  following  p.503. 


INDEX  TO  (JUAPTOLITES  01«  NEW  YOKE.  PART  1 


1ST 


Christiania,  graptolite  fauna,  505,  507, 
602,  636,  638,  647,  G57,  060,  609,  691,  695, 
710,  713,  folloxcing  p.503. 

Cincinnati  shales,  lower,  following  p.503. 
Cladophora,  544. 

Clarke,  John  M.,  acknowledgments  to, 
457 ;  cited,  480. 

Classification  of  graptolites,  543-74. 
Clathrograptus,  518,  545,  547. 

Cleland,  H.  F.,  mentioned,  585. 
Clematograptus,  612,  613,  614. 
implicatus,  613. 

Climacograptidae,  489,  517,  518,  538,  539, 
572,  574,  729-34. 

Climacograptidi,  546. 

Climacograptus,  474,  476,  478,  483*,  498, 
499,  508,  538,  544-45,  546,  550,  551, 
570,  574,  579,  718,  729,  731,  744. 
sp.,  744. 
sp.  nov.,  730. 

?  (Cryptograptus)  antennarius,  506-7, 
574,  587,  608,  610,  725,  729,  731-32, 
following  p.503. 
explanation  of  plate,  780. 
zone,  498-500. 
bicornis,  514,  543. 
caudatus,  491,  following  p.503. 
kuckersianus,  538. 

pungens  sp.  nov.,  499,  500,  506-7,  574, 
729,  730. 

explanation  of  plate,  780. 
scharenbergi,  730. 
styloideus,  following  p.503. 
vasae,  following  p.503. 
wilsoni,  following  p.503. 

Clinton  formation,  species  from,  467. 


Clonograptus,  492,  494,  496,  531,  537,  544, 
545,  549,  555,  556,  562,  563,  566,  567, 
568,  571,  573,  612,  614,  617,  618,  620, 
745;  graptolites  derived  from,  556. 
i sp.,  656,  744. 

(Staurograptus)  dichotomus,  562,  563. 
cf.  flexilis,  496,  504-5,  573,  606.  618,  743, 
745. 

milesi,  617,  618. 

proximatus,  492,  502,  601,  603,  613,  614. 
rigidus.  496,  589,  743,  745. 

var.  tenellus,  743. 
tenellus,  502. 

thureaui,  see  Dichograptus  (Clonograp¬ 
tus,  Goniograptus)  thureaui. 
Clonograptus  bed,  496. 

Clonograptus  subzone,  folloxoing  p.503. 
Cluysenaar,  cited,  636;  mentioned,  710. 
Cnidaria,  521. 

Coenograptidae,  564,  571,  572,  573,  701-3. 
Coenograptus,  497,  509,  537,  544,  564,  566, 
567,  568,  571,  645,  702,  717. 
gracilis,  564,  565,  571,  666,  701,  703,  717, 
following  p.503. 

Coenosarcal  canal,  486. 

Colonie,  483. 

Columbia  county,  species  from,  467. 
Common  canal,  486. 

Connecting  canal,  484,  536. 

Conularia  trentonensis,  491. 

Conularias,  518. 

Correlation  table  of  zones  in  the  Cambric 
and  Champlainic  of  the  slate  belt  of 
New  York,  following  p.503. 

Corynoides  curtus,  following  p.503. 
Cowhead,  Newfoundland, graptolite  fauna, 
495,  651.  656,  710. 


r 


788 


NEW  YORK  STATE  MUSEUM 


Crossing  canal,  484,  536,  550. 
Cryptograptus,  498,  731,  732. 
antennarius,  see  Climaeograptus? 

(Cryptograptus)  antennarius. 
hopkinsoni,  732. 

tricornis,  491,  732,  following  p.503. 
Ctenograptus,  537. 

Cumings,  E.  R.,  cited,  526,  534. 

Cups,  485. 

Cysts,  521. 

Dalarne,  Sweden,  graptolite  fauna,  505, 

507,  636,  681. 

Dale,  T.  N.,  cited,  496;  mentioned,  601; 

collections  by,  618,  646. 

Dalecarlia,  graptolite  fauna,  647,  657. 
Dames,  W.,  cited,  461,  592,  603. 

Darriwill  series,  744. 

Dawson,  cited,  492,  601 ;  mentioned,  608. 
Dawsonia,  495,  508,  521,  574,  735-40. 
acuminata,  738,  739,  741. 
campanulata,  739. 

monodon,  506-7,  574,  737,  740,  741-42. 
explanation  of  plate,  783. 
figure,  742. 
rotunda,  739. 
tenuistriata,  739. 
tridens,  506-7,  574,  740,  741. 
explanation  of  plate,  783. 

Dease  river,  graptolite  fauna,  following 
p.503. 

Deep  kill,  Goniograptus  from,  471 ;  grap¬ 
tolite  fauna,  491,  494,  498,  503,  504,  506, 

508,  540,  542,  550,  555,  560,  579,  581,  583, 
584,  589,  590,  591,  607,  608,  609,  610,  612, 
620,  621,  623,  625,  629,  633,  636,  637,  638, 
639,  640,  646.  648,  651,  657,  659,  661,  662, 
664,  666,  670,  672,  673,  675,  678,  682,  690, 


694,  705,  708,  711,  712,  715,  718,  719,  720, 
721,  722,  723,  726,  728,  729,  730,  731,  734, 
739,  740,  741,  742,  745,  following  p.503. 
Defreestville,  graptolite  fauna,  606,  753. 
Dendrograptidae,  571,  572,  578-612;  phy- 
logeny,  553. 

Dendrograptidi,  546,  548. 

Dendrograptus,  469,  477,  478,  495,  500, 
503,  508,  536,  537,  540,  544,  546,  567, 
571,  572,  578-79,  584,  587;  phyloge¬ 
netic  relations  of  genera,  553. 
sp.,  499,  744. 
sp.  nov.,  581,  582. 

(Callograptus?)  diffusus,  586. 
divergens,  580. 
erectus,  581. 

.  flexuosus,  504-5,  572,  579-80,  583. 

explanation  of  plate,  754. 
fluitans  sp.  nov.,  504-5,  572,  582-83. 

explanation  of  plate,  754. 
fruticosus,  580. 
cf.  gracilis,  579. 
hallianus,  578,  582. 
serpens,  581. 

succulentus  sp.  nov.,  504-5,  572,  578, 
580,  581-82. 

explanation  of  plate,  754. 
figures,  581,  582. 

Dendroid,  522. 

Dendi’oidea,  477,  483,  488,  495,  497,  500, 
503,  509,  513,  514,  515,  521,  522,  523,  526, 
529,  535,  536,  537,  539,  544,  546,  567,  570, 
571.  572,  578-612;  synoptic  table  of 
range  of  genera,  508 ;  relation  to  Grap- 
toloidea,  548-49;  phylogenetic  relations 
of  genera,  553. 

Denticles,  485. 

Descriptions  of  graptolites,  578-734. 


INDEX  TO  GRAPTOLITES  OF  NEW  YORK,  PART  1 


789 


Desmograptus,  508,  571,  573,  599,  609; 
phylogenetic  relations  of  genera,  553. 
cancellatus,  504-5,  573,  609,  610-11. 
explanation  of  plate,  752. 
figure,  610. 
devonicus,  599. 

intricatus  sp.  nov.,  504-5,  573,  599,  609, 

611-12. 

explanation  of  plate,  752. 
figures,  609,  611,  612. 
macrodictyum,  610,  611. 

Dicellocephalus  fauna,  493. 

Dicellograptus,  474,  544,  546,  552,  553,  666. 
anceps,  following  p.503. 
complanatus,  folloicing  p.503. 
divaricatus  var.  rigida,  514. 
moffatensis,  552. 

Dicellograptus  zone,  lower,  following 
p.503;  upper,  following  p.503. 
Dichograpsus  aranea,  634,  637. 
octobrachiatus,  635. 
sedgewickii,  637. 

Dichograptid,  522;  figure  showing  sicula, 
520. 

Dichograptidae,  468,  475,  476,  478,  483, 
486,  487,  489,  494,  497,  499,  515,  517,  525, 
527,  528,  529,  530,  531,  532,  535,  536,  538, 
544,  545,  546,  547,  548,  549,  550,  551,  554, 
555,  563,  564,  567,  571,  573,  604,  612-701; 
phytogeny  of,  553,  554;  supposed  causes 
of  evolution,  542,  567-70. 

Dichograptidi,  546. 

Dichograptus,  470,  473,  508,  516,  531,  535, 
537,  544,  554,  563,  566,  567,  568,  571, 
573.  620,  630,  634,  637,  folloicing 
p.503. 

sp.  figure  541. 
hexabrachiatus,  637. 


Dichograptus  kjerulfi,  631,  633. 
logani,  631,  632. 

octobrachiatus,  494,  495,  497,  504-5,  542, 
556,  573,  585,  630,  633,  634r-37,  669, 
683,  686,  744,  746. 
explanation  of  plates,  762,  764. 
et  hexabrachiatus,  635. 
octonarius,  556,  634,  744. 
separatus,  559,  634. 

(Glonograptus,  Goniograptus)  thureaui, 
621. 

Dichograptus  beds,  495,  636. 

Dichograptus  zone,  folloicing  p.503. 

Dichotomous  branching,  485. 

Dicranograptidae,  544. 

Dicranograptus,  474,  544,  546,  553. 
clingani,  folloicing  p.503. 

Dictyograptus,  599. 
n.  sp.,  608. 

(Desmograptus)  cancellatus,  610,  611. 
flabelliformis,  600. 

Dictyonema,  467,  469,  476,  477,  478,  495, 
503,  508,  509,  513,  527,  535,  536,  537, 
544,  546,  549,  556,  563,  571,  573,  578, 
579,  584,  591-99,  604,  743;  mode  of 
life,  593 ;  phylogenetic  relations  of 
genera,  553. 

(Desmograptus)  sp.  nov.,  606,  607,  611. 
blairi,  488. 

(Desmograptus)  cancellatum,  610. 
cavernosum,  594,  596,  598,  604,  607. 

figures,  595,  597. 
cervicorne,  607. 

figure,  592. 
delicatulum,  607,  608. 
flabelliforme,  478,  479,  504-5,  515,  521, 
526,  527,  535,  549,  563,  567,  573,  586, 
592,  593,  594,  595,  597,  598,  599-606, 
614,  615,  following  p.503. 


790 


NEW  YORK  STATE  MUSEUM 


Dictyonema  flabelliforme,  explanation 
of  plate,  748-49. 
figures,  601,  602. 
var.  confertum,  605. 

explanation  of  plate,  749. 
mut.  norvegicum,  605. 
zone,  491,  492-93,  501-2,  508. 
furciferum  sp.  nov.,  504-5,  573,  606-7. 
explanation  of  plate,  752. 
figure,  607. 
graptolithinum,  600. 
liisingeri,  599. 
iri’egularis,  496. 

murrayi,  496,  504-5,  573,  606,  656. 

explanation  of  plate,  753. 
norvegicum,  600,  605. 

var.  acadicum,  605. 
peltatum,  549,  607. 
perexile,  608. 
rarum,  figures,  593,  594. 
rectilineatum  sp.  nov.,  504-5,  573,  607-9, 
612. 

explanation  of  plate,  752. 
figure,  608. 
robusta,  496. 
sadewitzense,  600. 
sociale,  600. 
tuberosum,  599. 

Dictyonema  zone,  490. 

Didymograpsus  bryonoides,  see  Grapto- 
lites  (Didymograpsus)  bryonoides. 
eaduceus,  655,  658,  693. 
extensus,  see  Graptolites  (Didymograp¬ 
sus)  extensus. 

fruticosus.  see  Graptolites  (Didymo¬ 
grapsus)  fruticosus. 
geminus,  692. 


Didymograpsus  logani,  sec  Graptolites 
( Didymograpsus )  logani. 
nitidus,  671. 

octobracliiatus,  see  Graptolites  (Didy¬ 
mograpsus)  octobrachiatus. 
quadribrachiatus,  see  Graptolites  (Didy¬ 
mograpsus)  quadribrachiatus. 
Didymograptidae,  530,  546,  550,  718-29. 
Didymograptini,  546. 

Didymograptus,  474,  476,  478,  494,  495, 
497,  508,  509,  516,  531,  535,  537,  544, 
549,  552,  554,  555,  560,  562,  563,  566, 
567,  568,  571,  573,  610,  660,  666-68, 
695,  743,  744. 
figure,  485. 

(Leptograptus)  sp.,  680. 
sp.  nov.,  679,  682,  700. 
acutidens,  506-7,  560,  573,  667,  683-84, 
685. 

explanation  of  plate,  773. 
figures,  683,  684. 

affinis,  555,  562,  667,  682,  683,  688. 
arcuatus,  556. 
balticus,  679. 

bifidus,  497,  498,  499,  506-7,  536,  555.  . 
557,  559,  573,  579,  586,  590,  591,  608, 
609,  621,  623,  626,  627,  629,  636,  651, 
652,  654,  657,  659,  660,  665,  666,  667, 
670,  675,  678,  680,  ?683,  688,  689-92, 
693,  694,  703,  707,  710,  713,  715,  744, 

745,  746,  following  p.503. 
explanation  of  plate,  776. 
figure,  691. 

zone,  496-98,  504,  506,  508,  653,  656, 

746. 

(Isograptus)  eaduceus,  506-7,  550,  573. 
658,  660,  662,  668,  693-98,  699,  700, 
744. 

explanation  of  plate,  776. 


INDEX  TO  GRAPTOLITES  OF  NEW  YORK,  PART  1 


791 


Didymograptus  caduceus  nanus  mat. 
nov.,  506-7,  668,  698,  700. 
explanation  of  plate,  776. 
figure,  698. 

(gibberulus)  497,  550,  551,  555,  562, 
570,  653,  654,  677,  693,  694,  696,  697, 
698,  699. 

constrictus,  585,  668,  670,  671. 
cuspidatus  sp.  nov.,  499,  500,  506-7,  560, 
573,  667,  684-85. 
explanation  of  plate,  773. 
figures,  684,  6S5. 
decens,  678,  679,  744. 

(indentus)  dentatus,  655. 
ellesi  sp.  nov.,  506,  557,  558,  573,  667, 
682-83. 

explanation  of  plate,  775. 
figures,  682. 

extensus,  504-5,  516,  548,  556,  557,  562, 
569,  573,  608,  648,  667,  668-71,  672, 
673,  678. 

explanation  of  plates,  773,  774. 
figures,  669,  670. 

filiformis,  499,  500,  506-7,  561,  562,  565, 
573,  667,  686-87. 
explanation  of  plate,  774. 
forcipiformis  sp.  nov.,  499,  506-7,  562, 
573,  668,  699-700. 
explanation  of  plate,  776. 
figure,  699. 
fractus,  652. 

?  fruticosus,  649. 
furcillatus,  555,  559,  608. 
geminus,  following  p.503. 

(Isograptus)  gibberulus,  669,  694. 

var.  nanus  var.  nov.,  694. 
gracilis,  499,  500,  506-7,  533,  555,  558, 
561,  562,  565,  573,  667,  679-81,  682, 


Didymograptus  gracilis,  explanation  of 
plate,  775. 
figure,  533. 

incertus  sp.  nov.,  506-7,  552,  573,  668, 

700-1. 

explanation  of  plate,  777. 
figure,  700. 

indentus,  555,  559,  667,  693. 

var.  nanus,  692. 
murchisoni,  637,  667,  690,  744. 
nanus,  497,  506-7,  573,  667,  680,  682, 
692-93. 

explanation  of  plate,  776. 
nicholsoni,  555,  557,  558,  562,  675. 
var.  planus,  506-7,  573,  667,  685-86, 
688. 

explanation  of  plate,  773. 
figures,  685,  686. 

nitidus,  504-5,  530,  557,  562,  569,  573, 
663,  667,  671-74,  675,  676,  677, 
679. 

explanation  of  plates,  772,  774. 
figures,  672,  673. 
var.  grandis,  674. 
explanation  of  plate,  772. 
patulus,  504-5,  516,  530,  535,  556,  557, 
569,  573,  667,  671,  673-74,  674^-77. 
explanation  of  plates,  772,  774. 
figures,  675,  676,  677. 
pennatulus,  608. 

Sagittarius,  678. 

similis,  497,  506-7,  557,  573,  652,  667, 
677-79,  688. 

explanation  of  plate,  775. 
figures,  678. 

spinosus  sp.  nov.,  499,  500,  506-7,  558, 
573.  667,  688-89. 
explanation  of  plate,  775. 
figures,  689. 


792 


NEW  YORK  STATE  MUSEUM 


Didymograptus  suecicus,  678,  679. 
(Goniograptus)  thureaui,  621. 
tornquisti  sp.  nov.,  506,  530,  573,  667, 
688. 

explanation  of  plate,  772. 

Dimorphograptus,  475,  478,  526,  547. 

Diplograpsus,  470. 
antennarius,  731. 
folium.  710. 

Diplograptidae,  489,  499,  514,  517,  518, 
538,  539,  544,  545,  547,  550,  551,  570,  571, 
572,  574,  718-29. 

Diplograptidi,  546. 

Diplograptus,  468,  474,  476,  478,  479,  483, 
486,  488,  499,  508,  510,  511,  513,  518, 
519,  521,  522,  525,  529,  538,  539,  540, 
542,  545,  547,  550,  551,  552,  570,  572, 
574,  577,  579,  718-19,  731. 
sp .,  744. 

figures,  520,  529. 
sp.  nov .,  722,  following  p.503. 
amplexicaulis,  491,  following  p.503. 
angustifolius,  following  p.503. 
appendiculatus,  535,  723. 
cancellatus,  612. 

dentatus,  499,  500,  503,  506-7,  539,  550, 
552,  557,  574,  580,  581,  586,  587,  589, 
608,  609,  610,  611,  612,  626,  632,  636, 
637,  646,  664,  665,  672,  678,  680,  685, 
687,  689,  690,  693,  695,  698,  699,  700, 
712,  713,  715,  716,  718,  719-21,  723, 
725,  726,  728-29,  730,  731,  732,  734, 
745,  746,  778,  folioicing  p.503. 
explanation  of  plate,  782. 
figure,  720. 

zone,  498-500,  504.  506,  508,  722. 
foliaceus,  478,  479,  525,  526,  528,  542, 
following  p.503. 
figures,  528. 


Diplograptus  inutilis,  506-7,  574,  718, 
721. 

explanation  of  plate,  779. 
laxus  sp.  nov.,  499,  500,  506-7,  519,  574, 
718,  722-23. 

explanation  of  plate,  779. 
longicaudatus  sp.  nov.,  506-7,  574,  718, 
723. 

explanation  of  plate,  779. 
physophora,  514,  519. 
pristiniformis,  719. 

(dentatus),  637. 
pristis,  542,  following  p.503. 
pusillus,  folloicing  p.503. 
putillus,  722. 

quadrimucronatus,  folloiving  p.503. 
sertularioideus,  723. 
teretiusculus,  723. 
vesiculosus,  519,  723. 
whitfieldi,  477,  520. 

Diprion,  718. 

Diprionidae,  475,  544,  545. 

Diprionidian,  484. 

Discograptus  schmidti,  596. 

Disk,  central,  487. 

Dorsal  edge  of  canal,  486. 

Dorsal  wall,  486. 

Dumfriesshire,  black  shales  of,  470. 

Dun,  W.  S.,  cited,  743. 

Ellergill  beds,  633,  720,  725,  726,  729,  730. 
734.  following  p.503.  See  also  Skiddaw 
slates. 

Elies,  G.  L.,  cited,  459,  465,  471,  478,  484, 
485,  495,  502,  525,  535,  536,  549,  550,  554. 
555,  556,  558,  563,  616,  617,  618,  631,  633, 
634,  637,  638,  639,  640,  641,  643,  644,  648. 
653,  661,  667,  673,  675,  676,  687.  690,  695, 
696,  699,  706.  70S,  709,  711,  713,  715,  717, 


INDEX  TO  GRAPTOLITES  OF  NEW  YORK,  PART  1 


793 


720,  724,  726,  727,  729,  730,  731,  732,  fol¬ 
ioicing  p.503 ;  investigations,  553  ;  men¬ 
tioned,  567. 

Emmons,  E.,  cited,  459,  460,  467,  612,  J16, 
717 ;  mentioned,  615. 

England,  graptolite  fauna,  469,  490,  505, 
507,  512,  633,  636,660;  Dictyonema  zone, 
492 ;  Tetragraptus  zone,  495.  See  also 
Ellergill  beds;  Lake  district. 

Esthland,  Dictyonema  zone,  492. 

Estkonia,  graptolite  fauna,  602,  following 
p.503. 

Etagraptus,  644-45. 

lentus,  see  Tetragraptus  (Etagraptus) 
lentus. 

Etheridge,  R.  jr,  cited,  461,  471,  495,  660, 
673,  695,  697,  735,  736. 

Eudendrium,  521. 
ramosum,  524. 
figures,  523. 

Europe,  graptolite  fauna,  502,  601,  602; 

Tetragraptus  zone,  495. 

Explanation  of  plates,  747-53. 

Fairhaven  (Vt.),  Dictyonema  zone,  493; 

graptolite  fauna,  601. 

Fenestella  flabelliformis,  599. 
Fichtelgebirge,  graptolite  shales,  471. 
France,  graptolite  fauna,  471,  488,  489, 

502,  505,  507,  folioicing  p.503;  Tetra 
graptus  zone,  495;  St  Anne  zone,  498. 
See  also  Boutoury. 

Freeh,  F.,  cited,  459,  465.  484,  488,  501, 

503,  514,  515,  521,  536,  542,  545,  546,  547, 
548,  570,  571,  572,  577,  588,  592,  617,  620, 
630,  669,  693,  695,  718,  723,  724,  732,  733, 
734,  746. 

Frond.  483. 


Fucoides  dentatus,  719. 

serra,  655. 

“  Funicle,”  473,  486. 

“  Fuss,”  473,  484. 

/ 

Gaspe,  graptolite  fauna,  following  p.503. 
Geinitz,  H.  B.,  cited,  459,  460,  467,  468, 
470,  509. 

Gembloux,  shale  of,  following  p.503. 
Gemeinsamer  Canal,  486. 

Germany,  graptolites  from,  471. 

Girvan,  graptolite  shales,  512. 

Glenkiln  shales,  following  p.503. 
Glossograpsus,  467. 

Glossograptidae,  545. 

Glossograptus,  499,  508,  539,  545,  547,  550, 
572,  574,718.  724,  744,  following  p.503. 
sp.  nov.,  724. 
armatus,  725,  726. 

echinatus  sp.  non.,  506-7,  574,  725-26. 
explanation  of  plate,  781. 
figure,  726. 

fimbriatus,  725,  726,  734, 
hincksii,  725,  726. 

hystrix  sp.  nov.,  499,  506-7,  574,  724-25, 
726. 

explanation  of  plate,  781. 
figure,  725. 

Goniograptus,  471,  494,  503,  508,  528,  532, 
533,  534,  536,  542,  566,  567,  571,  573, 

620-21. 

sp.  nov.,  625,  627. 

geometricus  sp.  nov.,  497,  504-5,  565, 
573,  627-30,  652,  654,  665,  666,  680, 
688. 

explanation  of  plate,  760-61. 
figures,  628,  629. 


794 


NEW  YORK  STATE  MUSEUM 


Goniograptus  macer,  744. 
perflexilis  sp.  not.,  500,  504-5,  559,  561, 
565,  573,  625-27,  644,  662-63,  681. 
explanation  of  plate,  759,  760. 
figures,  625,  626,  627. 
mut.,  499. 

thureaui,  478,  479,  503,  504-5,  526,  527, 
531,  569,  573,  621-24,  626,  627, 
631,  638,  652,  661,  744. 
figures,  622. 
var.  postreinus,  623. 
var.  nov.,  explanation  of  plate,  758-59. 
var.  selwvni,  621. 

Goniograptus  subzone,  following  p.503. 

Gorgonia  flabelliformis,  599. 

Gothland,  graptolite  fauna,  592,  597,  602, 
607. 

Gotliograptus,  518,  547,  733. 

Grabau,  A.  W., discovery  of  Phyllograptus, 
499. 

Granville,  graptolite  fauna,  595,  601; 
Dictyonema  zone,  493. 

Graptolite  shales,  479,  695. 

Graptolites, animal  nature, 467 ;  central  or 
basal  portions  of  colonies,  473;  classifi¬ 
cation  and  phvlogeny,  543-74 ;  derived 
from  Bryograptus,  555;  derived  from 
Clonograptus,  556;  descriptions,  578- 
734;  some  general  facts  of  distribution, 
500-3;  Hall’s  views,  468;  histology  and 
chemical  composition  of  the  periderm, 
539-43;  history  of  the  study  of,  466-78; 
similarity  to  hydrozoans,  467 ;  internal  j 
structure,  472;  methods  of  illustration, 
481 ;  methods  of  investigation  and  illus¬ 
tration,  479-82;  mode  of  existence,  469, 
478,  509-19;  mode  of  reproduction 
and  development,  477-78;  mode  of  re¬ 
production  and  ontogeny,  519-34;  mode 


of  suspension,  515 ;  phylogeny  of  genera 
and  species,  478,  553-67 ;  phylogeny  of 
orders,  548-53;  range  and  geographic 
distribution,  488-508;  stratigraphic  re¬ 
lations,  469;  structure  and  morphology. 
534-39 ;  taxonomic  relations,  574-77 ; 
term,  466;  terminology,  482-88;  vege¬ 
table  origin,  466. 

Graptolites  (Didymograpsus)  bryonoides, 
655. 

caduceus,  658,  693. 
extensus,  668. 
fruticosus,  649. 
gracilis,  679. 
logani,  631. 
octobrachiatus,  635. 
quadribrachiatus,  645. 
thureaui,  621. 

Graptolithus,  466,  477,  574. 
bifidus,  689. 
bigsbyi,  658. 
bryonoides,  647,  655. 
caduceus,  697. 
constrict  us,  668. 
divergens,  701. 
extensus,  668. 
flexilis,  618. 
fruticosus,  649. 
logani,  630,  631. 
milesi,  544,  617. 
multifasciatus,  544. 
nitidus,  671. 

octobrachiatus,  634,  635. 
patulus,  674. 
pristiniformis,  719. 
quadribrachiatus,  645. 
ramosus,  473. 
richardsoni,  544. 
similis,  660. 


INDEX  TO  GRAPTOLITES  OF  NEW  YORK.  PART  1 


795 


Graptolithus  tenitaculatus,  733. 
vagans,  544. 

Graptolitidae,  544,  545,  570. 

Graptoloidea,  487,  488,  503,  509,  514,  515, 
522,  520,  530,  537,  539,  540,  571,  573,  574, 
004,  012-734;  canal  in,  480;  relation  to 
Dendroidea,  548-49. 

Graptopora  socialis,  599. 

Graptotliecae,  485. 

Great  Britain,  graptolite  fauna,  470,  471, 
472,  474,  488,  489,  490,  498,  512,  040,  073, 
090,  710,  713;  graptolite  zones,  correla¬ 
tion  table,  following  p.  503;  Dictyonema 
zone,  492-93.  See  also  Lake  district; 
Scotland;  Wales. 

Greenfield  limestone,  493. 

Grenarne,  4S4. 

Gros  Maule,  Canada,  graptolite  fauna. 
585. 

Guinbel,  C.  W.,  cited,  402,  470,  477,  480, 
539-40,  543. 

Gurich,  G.,  cited,  404,  477,  480,  511,  515, 
540. 

Gurley,  R.  R.,  cited,  404,  405,  472,  488,  490, 

495,  498,  580,  585,  589,  590,  599,  G0S,  611, 
033,  030,  651,  656,  060,  072,  675,  690,  710, 
715,  717,  720,  721,  728,  731,  735,  737,  73S, 
740,  741,  745,  following  p.503. 

Haftorgan,  484. 

Hall,  James,  cited,  457,  459,  400,  406,  467, 
468,  469,  471,  473,  477,  479,  480,  487,  490, 

496,  497,  509,  517,  519,  520,  527,  544,  574, 
582,  583,  585,  587,  588,  589,  590,  591,  593, 
613,  629,  630,  632,  634,  036,  037,  647,  048, 
651,  656,  657,  059,  660,  661,  070,  071.  072, 
675,  676,  678,  690,  092,  703,  705,  700,  709, 
710,  715,  710,  717,  721,  724,  728,  729,  731, 
732,  734 ;  mentioned,  046,  069. 


Hall,  T.  S.,  cited,  464,  498,  743,  744,  745, 
746. 

Hamilton  group,  Uictyonemas  in,  509. 

Harkness,  cited,  470. 

Hartfell  shales,  following  p.503. 

Hartz,  graptolites,  474. 

Haut,  486. 

Hector,  James,  cited,  743. 

Herrmann,  M.  O.,  cited,  403,  475,  509,  617, 
630,  030,  673,  076,  091. 

Hicks,  cited,  730. 

Hillsdale,  graptolite  fauna,  001,  615,  617. 

Hisinger,  W.,  cited,  459. 

Holm,  G.,  specimens  drawn  by,  481 ;  cited, 
462,  463,  404,  476,  478,  480,  484,  485,  495, 
520,  521,  523,  525,  520,  534,  530,  547,  563, 
584,  592,  597,  598,  643,  660,  601,  665,  695, 
705,  706;  mentioned,  713. 

Holograptus,  537,  618. 
richardsoni,  619,  620. 

Hopkinson,  J.,  cited,  461,  462,  470,  474, 
475,  503,  544,  548,  580,  5S2,  583,  585,  586, 
587,  588,  599,  609,  657,  666,  720,  729. 

Hudson,  see  Mt  Moreno. 

Hudson  river  shales,  species  from,  467;  in¬ 
vestigation  of,  472;  position,  490 ;  faunal 
zones,  490,  491. 

Hunneberg,  fauna,  669. 

Huxley,  cited,  477. 

Huy-Statte,  Belgium,  graptolite  fauna, 
710,  following  p.503. 

Hyatt,  cited,  534,  550. 

Ilydrocaulus,  487. 

Hydroidea,  474,  518,  521,  522,  525,  526, 
576. 

Hydrorhabd,  484. 

Hydro-some,  483. 

llvdrothecae,  485. 

Hydrozoa,  477,  514,  532,  577. 


796 


NEW  YORK  STATE  MUSEUM 


Initial  point,  484. 

Inocaulis,  477,  478,  537. 

Ireland,  Dictyonema  zone,  492 ;  graptolite 
fauna,  602.  See  also  Kiltrea. 

Isograptus,  695,  696. 
caduceus,  see  Didymograptus  (Iso¬ 
graptus)  caduceus. 

gibberulus,  see  Didymograptus  (Iso¬ 
graptus)  gibberulus. 

Jackson,  R.  T.,  cited,  532,  624. 

Jaekel,  O.,  cited,  463,  475,  510,  511,  515. 

Jones,  cited,  735,  736,  737. 

Kerforne,  cited,  471. 

Kicking  Horse  pass,  graptolite  fauna,  fol¬ 
lowing  p.503. 

Kiltrea,  Ireland,  graptolite  fauna,  675. 

Krekling,  Norway,  graptolite  fauna,  660, 
676,  687,  693. 

Lake  district,  graptolite  fauna,  651,  653, 
654,  657,  669,  672,  686,  691,  693,  710,  715. 

Lake  St  John,  Canada,  graptolites  from, 
468. 

Laneefield  series,  743,  745. 

Languedoc,  graptolite  fauna,  647. 

Lansingburg,  graptolite  fauna,  folloiving 
p.503. 

Lapwortli,  C.,  microscope  constructed  by, 
481 ;  cited,  461,  462,  463,  470,  472,  473, 
474,  475,  476,  478,  479,  484,  485,  487,  488, 
489,  490,  192,  497,  498,  503,  511-12,  512- 
13,  514,  515,  520.  526,  544,  545,  546,  547, 
549,  568,  570,  571,  580,  582,  583,  585,  587, 
595,  596.  597,  602,  60S,  613,  620,  634,  648, 
657,  669,  670,  672,  673,  675,  676,  690,  693, 


695,  696,  704,  715,  717,  718,  720,  729,  731, 
732,  737,  739,  following  p.503. 
Lapworth,  H.,  cited,  465,  471. 
Lasiograptus,  518,  521,  541,  543,  545,  547, 
734,  744. 

Lateral  branching,  485. 

Latex^al  walls,  486. 

Lecrenier,  A.,  cited,  463,  636;  mentioned, 
710. 

Leptograptidae,  546,  571,  572. 
Leptograptus,  544,  571,  743. 

flaccidus,  following  p.503. 

Lindstrom,  Prof.,  cited,  511. 

Linea,  487. 

Lingula  flags,  505,  507,  following  p.503. 
Linnarsson,  G.,  cited,  462,  470,  489. 
Linnd,  C.  v.,  cited,  459,  466. 

Llandeilo  flags,  graptolite  fauna,  581,  739, 
following  p.503. 

Llanvirn  beds,  Wales,  graptolite  fauna, 
675,  683,  720,  following  p.503. 

Lleyn  peninsula,  Wales,  graptolite  fauna, 
669,  673. 

Loch  Ryan,  slates  of,  470. 

Logan,  cited,  470. 

Loganograptus,  508,  537,  544,  554,  563, 
568,  571,  573,  630-31,  637,  744,  745. 
kjerulfi,  635. 

logani,  504-5,  556,  573,  589,  631-33,  744, 
745. 

explanation  of  plate,  764. 

figure,  632. 

mat.  per  tenuis,  633. 

Lorraine  fauna,  490,  folloicing  p.503. 
Lossen,  cited,  474. 

Lower  Siluric  graptolites,  467,  472,  660, 
729. 

Lyddeker,  cited,  738. 


IXDEX  TO  GRAPTOLITES  OF  NEW  YORK.  PART  1 


797 


McCoy,  F.,  cited.  460,  461,  462,  470,  471, 
495,  620,  621,  623,  633,  636,  647,  651,  666,  I 
670,  695,  710,  718. 

Malaise,  C.,  cited,  463,  495,  636,  637,  710.  j 

Maquoketa  shales,  following  p.503. 

Marr,  J.  E.,  cited,  463,  464,  471,  478,  489, 
554,  555,  567,  640,  736;  investigations, 
553 ;  mentioned,  567. 

Mather,  W.  W„  cited,  459. 

Matthew,  G.  F.,  cited,  464,  465,  472,  481, 
492,  495,  592,  594,  596,  598,  602,  603,  605, 
606,  613,  615,  616,  633,  672,  675,  734, 
following  p.503;  mentioned,  646. 

Mechanicville,  graptolite  fauna,  following 
p.  503. 

Middle  Skiddaw  slates,  653. 

Mississippi  valley,  upper  Maquoketa 
shales,  following  p.503. 

Moberg,  J.  C.,  cited,  463,  464,  599,  695. 

Moffat  shales,  512.  folioicing  p.503. 

Mohawk  valley,  graptolite  from,  585. 

Monoclimacis,  546. 

Mono-Dipriouidae,  544. 

Monograptidae,  489,  538,  544,  545. 

Monograptidi,  546,  547. 

Monograptus,  475,  478,  480,  509,  540,  553. 
pala,  514. 
priodon,  540. 

Monopodial  branching,  485. 

Monoprionidae,  475,  484,  544,  545. 

Mossebo,  graptolite  fauna,  687. 

Mt  Moreno,  graptolite  fauna,  498,  499, 
508,  550,  589,  626,  627,  646,  664,  665,  678, 
680,  685,  687,  689,  699,  713,  715,  717,  719, 
720,  722,  725,  728,  730,  734,  following 
p.503. 

Multiramous  forms,  484. 

Murchison.  R.  J.,  cited,  459,  467. 


Nelson,  New  Zealand,  graptolite  fauna, 
746. 

Nema,  487. 

Nemacaulus,  487. 

Nemagrapsus,  467,  716. 
capillaris,  716,  717. 
elegans,  716. 

Nemagraptidae,  544. 

Nemagraptus,  544,  571,  717. 

Neumayr,  cited,  575,  577. 

Nevada,  graptolite  fauna,  498,  505,  507, 
690,  715,  738,  following  p.503;  Caryo- 
caris  from,  737. 

New  Brunswick,  graptolite  fauna,  633, 

672. 

New  Zealand,  graptolite  fauna,  695,  746. 
Newfoundland,  Tetragraptus  zone,  495; 
graptolite  fauna,  505,  507,  5S9,  follow¬ 
ing  p.503.  See  also  Cowhead. 

Niagara  group,  Dictyonemas  in,  509. 
Nicholson,  H.  A.,  cited,  460-61,  462,  463, 
470,  474,  477,  478,  488,  489,  509,  521,  544, 
554,  555,  567,  570,  574,  592,  593,  617,  618, 
633,  634,  657,  696,  697,  726,  727,  729,  731. 
735,  738,  739 ;  investigations,  553 ;  men¬ 
tioned,  567. 

Nilsson,  cited,  459,  467. 

Normanskill  shale,  470,  717,  following 
p.503;  fauna,  490,  739;  Diplograptus  in, 
468. 

Normanskill  zone,  490. 

North  America,  graptolites,  469,  472. 
North  Granville,  specimens  from,  601. 
Norway,  graptolite  fauna,  471,  636,  651, 

673.  See  also  Krekling. 

Obverse  aspect,  484. 

Oeland,  Tetragraptus  zone,  495;  grapto¬ 
lite  fauna.  660,  695,  705,  713. 


798 


NEW  YORK  STATE  MUSEUM 


Oesel,  Dictyonema  zone,  492;  graptolite 
fauna,  following  p.503. 

Ohio  valley,  graptolite  fauna,  following 
p.503;  upper  Maquoketa  shales,  follow¬ 
ing  p.503. 

Orleans  island,  graptolite  fauna,  589,  651. 
Orthoceras  limestone,  495,  498,  660. 
Orthoceratites,  467. 

Palaeozoicum,  736. 

Paterula,  739. 

Pauciramous  forms,  484. 

Periderm,  486;  histology  of,  477. 

Perisarc,  4S6. 

Perner,  J.,  cited,  459,  464,  471,  477,  480, 
498,  540,  541,  660,  691,  692. 
Phyeograptus,  717. 

Phyllograpta  sp.,  599. 

Phyllograptidae,  530,  545,  546,  547,  550, 
563,  564,  567,  571,  573-74,  703-18. 
Phyllograptini,  546. 

Phyllograptus,  476,  480,  494,  497,  499,  508, 
509,  530,  537,  545,  546,  547,  571,  573, 
636,  703-6,  743,  746,  following  p.503. 
angustifolius,  495,  497,  499,  506-7,  547- 
48,  555,  563,  564,  573,  705,  706,  708, 
711-14,  715,  744. 
explanation  of  plate,  778. 
figures,  704,  713. 

anna,  497,  498,  506-7,  563,  564,  573,  651, 
654,  669,  670,  678,  683,  703,  706, 
714-16,  following  p.503. 
explanation  of  plate,  777-78. 
figures,  715. 

zone,  490,  496-98,  505,  507,  651,  656, 
678,  690. 

mut.  pygmaeus,  547,  716. 
mut.  ultimus,  715,  778. 


Phyllograptus  densus,  679. 
folium  var.  tvpus,  708. 
ilicifolius,  480,  497,  506-7,  540,  563,  564, 
573,  648,  669,  705,  706-8,  711,  712, 
713,  714,  715,  716. 
explanation  of  plate,  777. 
figures,  707. 

var.  grandis,  706,  707,  708. 
similis,  658,  660. 
stella,  693,  695. 

typus,  494,  497,  498,  506-7,  563,  564,  573, 
580,  586,  608,  653,  654,  706,  708-11, 
720,  744,  745,  following  p.503. 
explanation  of  plate,  778. 
zone,  496-98,  691,  713. 

Phyllograptus  shale,  505,  507,  651,  680, 
670,  673,  676,  681,  691. 

Phyllograptus  zone,  720. 

Phyllo-Tetragraptus  beds,  669,  679. 

Phytogeny  of  the  graptolites,  478;  of 
orders  of  graptolites,  548-53 ;  of  genera 
and  species  of  graptolites,  553-67 ;  of 
Dichograptidae,  553,  554. 

Plates,  explanation  of,  747-83. 

Pleurograptus,  537,  544,  566,  571,  701. 
linearis,  following  p.503. 

Plumularia,  467,  468,  588. 

Plumularidae,  474,  521,  575,  577. 

Pneumatocyst,  488. 

Pneumatophor,  518,  519. 

Point  Levis,  graptolite  fauna,  467,  491, 
503,  505,  507,  580,  581,  583,  587,  588,  589, 
590,  606,  609,  611,  622,  623,  632,  633,  636, 
646,  656,  659,  669,  672,  675,  689,  690,  710, 
713,  715,  721,  72S,  729,  731,  734,  738,  739, 
740,  741,  742,  745;  Caryocaris  from,  737. 

Point  Levis  zone,  495,  651,  656,  660,  675, 
710,  720,  following  p.503. 


INDEX  TO  GRAPTOLITES  OF  NEW  YORK,  TART  1 


799 


Polish  graptolite  horizons,  511. 
Polypariet,  483. 

Polypary,  483,  484. 

Polypidom,  483. 

Polypier,  483. 

Portloek,  J.  E.,  cited,  459,  467,  574. 
Potsdam  sandstone,  493. 

Primary  disk,  487. 

Pritchard,  G.  B.,  cited,  743. 

Pterograptus,  537,  566. 

Ptilograptus,  497,  500,  503,  508,  537,  571, 
572,  587-88;  phylogenetic  relations  of 
genera,  553. 

geinitzianus,  504-5,  572,  590. 

explanation  of  plate,  755. 
plumosus,  499,  504-5,  572,  588-89,  590, 
591. 

explanation  of  plate,  755. 
tenuissimus  sp.  nov.,  504-5,  572,  591. 
explanation  of  plate,  754. 

Quebec  group,  graptolite  fauna,  466,  468, 
469,  471,  490,  579,  659,  672,  690,  697,  713, 
721,  728,  731,  following  p.503.  See  also 
Point  Levis. 

Quenstedt,  F.  A.,  cited,  459,  467. 

Radicle,  484;  term,  509. 

Ramsey  island,  Wales,  graptolite  fauna, 
503,  580,  583,  587,  720,  729. 

Rensselaer  county,  graptolite  fauna,  492, 
601,  606,  615,  618,  646,  657,  749,  751,  752, 
753 ;  Clonograptus  beds,  496. 
Reticulograptus,  599. 

Retiograptus,  468,  486,  499,  508,  509,  518, 
539,  545,  546,  570,  572,  574,  732-33. 
eucharis,  545. 

tentaculatus,  499,  506-7,  574,  733-34. 
explanation  of  plate,  781. 


Retiolites,  476,  480,  509,  518,  540,  545,  547, 
550,  551,  732,  733. 
ensiformis,  727,  729. 
geinitzianus,  732. 
venosus,  733. 

Retiolitidae,  545,  547. 

Retiolitidi,  546. 

Retioloidea,  488,  544,  545,  546,  570. 

Reverse  aspect,  484. 

Rhabdinopora  flabelliformis,  600. 

Rhabdopliora,  474,  544,  570. 

Rliabdopleura,  474,  575. 

Rhabdosomes,  483,  484 ;  walls  of,  486. 

Rhizopoda,  575. 

Richter,  R.,  cited,  461,  462,  471,  473,  477, 
509,  539. 

Roemer,  F.,  cited,  459,  465,  620. 

Rouvilligraptus,  537,  618. 
richardsoni,  498. 

Ruedemann,  Rudolf,  cited,  464,  465,  466, 
471,  472,  478,  480,  487,  490,  492,  542,  601. 

Russia,  graptolite  fauna,  602,  following 
p.503. 

St  Anne  beds,  715. 

St  Anne  zone,  497,  498,  690,  following 
p.503. 

St  Davids,  Wales,  graptolite  fauna,  505, 
507,  585,  610,  646,  669,  673,  675,  683,  693, 
695,  739. 

St  Germain-sur-Ile,  graptolite  fauna,  fol¬ 
lowing  p.503. 

St  John  (N.  B.),  graptolite  fauna,  472, 
492,  495,  505,  507,  594,  596,  597,  605,  646, 
672,  following  p.503. 

St  Lawrence  region,  graptolite  fauna, 
740. 

Salter,  J.  W„  cited.  460,  470,  634,  636,  657, 
660,  735,  736. 


800 


NEW  YORK  STATE  MUSEUM 


Sandhurst,  Victoria,  Australia,  graptolite 
fauna,  621. 

Sargassum,  512. 

Sart-Bernard,  graptolite  fauna,  following 
p.503. 

Saxony,  graptolites,  470. 

Scandinavia,  graptolite  fauna,  470,  492, 
633,  657,  673;  graptolite  zones,  correla¬ 
tion  table  following  p.503. 

Scania,  Sweden,  graptolite  zones,  470,  488, 
498;  graptolite  fauna,  505,  507,  602,  660, 
669,  676,  687,  691,  695,  710,  713,  follow¬ 
ing  p.503 ;  Tetragraptus  zone,  647. 

Schaghticoke,  graptolite  fauna,  492,  595, 
596,  597,  601,  602,  605,  615,  616,  617,  749, 
751,  following  p.503. 

Schale,  486. 

Scharenberg,  W.,  cited,  460,  473,  475,  476, 
509. 

Seliizograptus,  537,  618. 

Schlothheim,  E.  F.,  cited,  459,  467. 

Schucliert,  Charles,  acknowledgments  to, 
458;  cited,  493,  503. 

Schultze’s  maceration  medium,  481. 

Scotland,  graptolite  fauna,  469,  470,  474, 
498,  505,  507,  647,  651,  657,  660,  715,  739, 
following  p.503 ;  Tetragraptus  zone,  495. 
See  also  Ballantrae. 

Seaweeds,  attachment  to,  513. 

Sedgwick,  A.,  cited,  459,  470. 

Sertularia,  467,  468,  477. 

Shropshire,  graptolite  fauna,  474,  669,  673, 
675,  683,  691 ;  Caradoc  shales,  following 
p.503. 

Sicula,  473,  474,  484 ;  term,  509 ;  details  of 
structure,  520. 

Sicular  end  of  rhabdosome,  484. 

Siculaseite,  484. 


Sigmagraptus  gen.  nov.,  497,  508,  537,  564, 
567,  571,  573,  701-2. 
praecursor  sp.  nov.,  506-7,  564,  565,  573, 
627,  645,  702-3. 
explanation  of  plate,  756. 
figure,  702. 

Siphonophora,  533,  577. 

O 

Skane,  graptolite  fauna,  657. 

Skiddaw  slates,  graptolite  fauna,  470,  498, 
502,  505,  507,  552,  554,  555,  633,  636,  637, 
640,  646,  648,  654,  657,  660,  669,  672,  675, 
686,  693,  708,  710,  715,  720,  726,  729,  731, 
734,  736,  739,  following  p.503.  See  also 
Ellergill  beds. 

Sollas,  J.  W.,  cited,  464,  540. 

South  Hartford,  specimens  from,  601. 
Spencer,  J.  W.,  cited,  462,  463,  472. 
Staurograpsus,  467. 

Staurograptus,  508,  549,  573,  612-17. 
dichotomus,  492,  493,  502,  504-5,  573, 
601,  613,  614-17,  639. 
explanation  of  plates,  750-51. 
figure,  613. 

See  also  Clonograptus  (Staurograp¬ 
tus)  dichotomus. 

var.  apertus  var.  nov.,  561,  566,  573, 

617. 

explanation  of  plate,  751. 

Stipes,  484. 

Stock,  483. 

Stomatograptus,  476,  518. 
Stromatoporidae,  577. 

Strophograptus  gen.  nov.,  508,  574,  716-17. 
trichomanes  sp.  nov.,  506-7,  574,  716, 

717-18. 

explanation  of  plate,  755. 

Suess,  cited,  470. 


INDEX  TO  GRAPTOLITES  OF  NEW  YORK,  PART  1 


801 


Sweden,  graptolite  fauna,  488,  489,  490, 
636,  651,  710,  720 ;  Tetragraptus  zone, 
495.  See  also  Dalarne;  Gothland; 
Scania. 

Synoptic  table  of  distribution  of  Cambric 
and  Lower  Champlainic  graptolites  of 
New  York,  504-7. 

Synoptic  table  of  range  of  genera  of  Cam¬ 
bric  and  Lower  Champlainic  of  New 
York,  508. 

Synrhabdosome,  483.  484. 

Taxonomic  relations  of  the  graptolites, 
574-77. 

Temnograptidae,  567. 

Temnograptus,  508,  537,  566,  567,  568,  572, 
573,  617,  618-19. 
milesi,  617. 

multiplex,  617,  618,  619,  620. 
noveboracensis  sp.  nov.,  506-7,  573,  619- 
20. 

explanation  of  plate,  757. 
figures,  619,  620. 

Terminology  of  graptolites,  482~88. 

Test,  486. 

Tetragrapsus  (bryonoides),  655. 
crucialis,  645. 
quadribracbiatus,  645. 

Tetragraptidae,  530,  550. 

Tetragraptini,  546. 

Tetragraptus,  470,  473,  476,  478,  497,  508, 
531,  535,  536,  537,  544,  549,  554,  555, 
560,  562,  563,  566,  567,  568,  571,  573, 
609,  610,  621,  630,  637,  642-44,  667, 
713,  742,  743,  746,  folloiving  p.503. 
sp.,  555. 

acanthonotus,  558,  689. 


Tetragraptus  amii,  494,  504-5,  536,  552, 
573,  643,  647-49,  657. 
explanation  of  plate,  768. 
figures,  648. 

approximatus,  608,  666. 
arcuatus,  589. 

bigsbyi,  495,  530,  555,  563,  568,  589,  608, 
639,  658,  660,  662,  664,  665,  696,  697, 
698. 

bryonoides,  608,  655,  656,  658,  693,  697. 
bryonoides  (=serra),  648. 
caduceus,  641,  658. 

clarkei  sp.  nov.,  497,  504-5,  556,  573,  643, 

652-53. 

explanation  of  plate,  769. 
fruticosus,  494,  504-5,  517,  530,  531,  542, 
555,  556,  557,  569,  573,  608,  643,  648, 
649-52,  654,  655,  663,  669,  686,  744. 
explanation  of  plate,  765,  766. 
figure,  531. 
mut.,  652,  653. 
campanulatus,  652. 
tubiformis,  652,  653. 
headi,  556. 
bicksii,  624. 

(Etagraptus)  lentus  sp.  nov., 504-5,  561, 
565,  572,  573,  643,  644,  666. 
explanation  of  plate,  764. 
pendens,  497,  504-5,  555,  573,  643,  653- 
55,  688. 

explanation  of  plate,  769. 
figure,  654. 

phyllograptoides,  555,  563. 
postletbwaitii,  555. 
projectus,  744. 

pvgmaeus  sp.  nov.,  499,  500,  504-5,  565, 
573,  643,  661,  664-65,  686. 
explanation  of  plate,  771. 


802 


NEW  YORK  STATE  MUSEUM 


Tetragraptus  quadribrachiatus,  494,  490, 
499,  504-5,  556,  573,  589,  606,  608, 
643,  644,  645-47,  649,  655,  657,  744. 
explanation  of  plate,  768. 
figures,  646,  647. 

serra,  494,  496,  504-5,  530,  548,  556,  573, 
580,  585,  606,  608,  643,  648,  649, 
655-57,  744. 

explanation  of  plate,  768. 
figures,  656,  657. 

similis,  494,  504-5,  550,  573,  643, 
658-62,  069,  086,  698,  705,  706. 
explanation  of  plate,  770. 
figures,  642,  644,  659,  660,  661. 
(bigsbyi)  similis,  567,  570,  661,  663,  665, 
705. 

taraxacum  sp.  nov.,  499,  500,  504-5,  530, 
531,  560,  561,  573,  643.  663-64. 
explanation  of  plate,  771. 
woodi  sp.  nov.,  573,  643,  662-63. 
explanation  of  plate,  770. 
Tetragraptus  beds,  639,  651,  659,  673,  fol¬ 
lowing  p.503. 

Tetragraptus  zone,  494-96,  501,  504,  506, 
508,  540,  636,  646,  647,  648,  660,  664,  665, 
669,  670,  672,  675,  687,  710,  746,  follow¬ 
ing  p.503. 

Tetraprionidae,  544,  545,  546. 
Thamnograptus  anna,  591,  627,  629,  630. 
Theca,  first,  484,  520. 

Thecae,  485;  length  of,  486. 

Thuringia,  graptolite  shales,  471. 
Tornquist,  A.,  cited,  465,  466. 

Tornquist,  S.  L.,  cited.  460,  462,  463,  464, 
465,  470,  476,  480,  483,  484,  489,  495,  536, 
550,  551,  599,  636,  651,  660,  669,  676,  678, 
679.  680,  681,  687,  695,  696,  704,  710,  734. 


Trenton  shales,  species  from,  467,  739,  fol¬ 
lowing  p.503. 

Triarthrus  becki,  following  p.503. 

Tribes  Hill,  graptolite  from,  585. 

,  Trigonograptus,  499,  508,  539,  545,  550, 
572,  574,  726-27,  744. 
sp.  ?,  744. 

ensiformis,  499,  506-7,  574,  587,  610, 
727-29. 

explanation  of  plate,  782. 
lanceolatus,  726,  727. 

Trochograptus,  537,  618. 

Troy,  graptolite  fauna,  following  p.503. 

Tullberg,  S.  A.,  cited,  462,  463,  470,  488, 
489,  495,  498,  592,  651,  657,  660,  678,  679, 
687,  704,  710. 

Ulrich,  cited,  493,  503. 

Upper  Helderberg  gi’oup,  Dictyonemas  in, 
509. 

Upper  Siluric  graptolites,  472. 

Utica  shale,  graptolite  fauna,  467,  468, 
470,  472,  490,  following  p.503;  Diplo- 
graptus,  510 ;  fragments  of  seaweeds, 
518. 

Utica  zone,  490. 

Vakkerb,  specimens  from,  605. 

van  Ingen,  Gilbert,  acknowledgments  to, 
45S;  graptolites  photographed  by,  481; 
cited,  594,  601. 

Van  Sclxaick  island,  graptolite  fauna,  fol- 
lowing  p.503. 

Vanuxem,  L.-,  cited,  459. 

Ventral  margin,  486. 

Ventral  wall,  486. 

Vermont,  Dictyonema  zone,  493;  grapto¬ 
lite  fauna,  504,  506,  601. 


INDEX  TO  GRAPTOLITES  OF  NEW  YORK,  PART  1 


803 


Victoria,  Australia,  graptolite  fauna,  471, 
495,  503,  621,  633,  636,  647,  651,  657,  660, 
673,  695,  710,  745,  following  p.503;  St 
Anne  zone,  498. 

Virginia,  species  from,  467. 

Virgula,  487. 

Virgularia,  467. 

Wahlenberg,  G.,  cited,  459,  467. 

Walch,  cited,  467. 

Wales,  graptolite  shales,  469,  512 ;  grapto¬ 
lite  fauna,  471,  490,  503,  505,  507,  579, 
581,  585,  588,  602,  636,  648,  657,  691,  fol¬ 
lowing  p.503;  Dictyonema  zone,  492; 
Tetragraptus  zone,  495.  See  also  Llan- 
virn;  Lleyn  peninsula;  Ramsey  island; 
St  Davids. 

Walther,  Johannes,  cited,  465,  478,  511. 

Washington  county,  Dictyonema  zone, 
493;  graptolite  fauna,  601,  615. 

Waterford,  graptolite  fauna,  following 
p.503. 

West  Gothland,  graptolite  fauna,  657,  676. 


West  Sandlake,  graptolite  fauna,  606. 

Westrogothia,  graptolite  fauna,  670,  695. 
See  also  Mossebo. 

Whitesand  bay,  Wales,  graptolite  fauna, 
580,  585,  610. 

Whitfield,  R.  P.,  acknowledgments  to,  458. 

Wiman,  C.,  cited,  459,  464,  465,  466,  475, 
476,  477,  478,  480,  483,  484,  485,  486,  487, 
510,  514,  515,  518,  520,  521,  523,  525,  526, 
527,  528,  535,  536,  537,  540,  541,  542,  543, 
545,  546,  548,  549,  576,  577,  578,  583,  584, 
588,  592,  594,  596,  597,  598,  604,  719; 
specimens  drawn  by,  481;  graptolites 
decolored  by,  481. 

Wood,  E.  M.  R.,  cited,  459,  465,  471,  484, 
525,  536,  550,  631,  633,  634,  637,  638,  640, 
641,  643,  644,  648,  667,  673,  675,  676,  687, 
690,  695.  696,  699,  708,  709,  713,  717. 

Woodward,  cited,  735,  736,  737. 

Zahne,  485. 

Zittel,  K.,  cited,  462,  466,  603. 

Zweige,  484. 


, 

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WELLESLEY  COLLEGE  LIBRARY 


3  5002  03641  6324 


Science  qQ1 1  N825 
7 

Graptolites  of  New 
York 

Ruedemann,  Rudolf,