262 
DR.  WHEELTON  HIND  ON  THE  AFFINITIES  OF  [May  I  893, 
Lunule  long  and  narrow.  The  lower  border  is  nearly  straight,  or 
very  slightly  sinuated ;  if  produced  anteriorly,  it  would  form  an 
angle  of  35°  with  the  hinge-line.  At  its  posterior  end  it  curves 
rapidly  upward  into  the  posterior  border,  which  is  bluntly  rounded 
below,  but  obliquely  truncated  above  its  superior  border.  Anterior 
end  short,  much  lower  than  the  umbones,  somewhat  acute,  with  a 
broad  diagonal  sulcus.  An  obtuse,  very  tumid  ridge  passes  from 
the  umbones,  diagonally  across  the  shell,  to  the  posterior-inferior 
angle.  Posterior  to  the  ridge,  the  shell  becomes  flattened  upward 
towards  the  hinge-line. 
Interior  unknown. 
Exterior  ornamented  by  fine  stride  and  lines  of  growth,  which 
become  rapidly  deflected  upward,  when  they  reach  the  oblique  groove, 
to  the  superior  border. 
Size. — Antero-posterior  measurement,  45  mm.  (14  inch)  ;  dorso- 
ventral,  28  mm.  (lyL-  inch);  from  side  to  side,  22  mm.  (ginch). 
Remarks. — This  species  was  the  first  member  of  the  genus 
to  be  figured,  and  described.  It  is  closely  allied  to  Anthracomya 
Adamsii ,  but  differs  in  its  dimensions.  The  greatest  thickness  is 
umbonal,  not,  as  in  A.  Adamsii ,  at  the  centre  of  the  shell ;  while 
the  relatively  greater  length,  compared  with  its  dorso- ventral 
measurement,  also  serves  to  distinguish  this  shell  ;  the  oblique 
ridge  and  sulcus  are  much  more  marked. 
Through  the  kindness  of  Prof.  Prestwick,  I  have  been  able  to 
examine  the  original  type-specimen.  It  is  without  the  anterior  end, 
the  absence  of  which  gives  a  much  more  quadrate  and  subparallel 
appearance  to  the  fossil.  I  have,  with  his  permission,  figured  it 
again.  It  is  for  this  reason  that  Sowerby,  in  his  description  of  the 
specimen,  says  its  anterior  side  is  small  and  rounded,  and  he  is 
followed  by  Salter  {op.  jam  cit .),  who  says  that  the  anterior  side  is 
almost  obsolete.  The  original  type  is  a  little  more  compressed  poste¬ 
riorly  than  the  specimen  from  North  Staffordshire.  The  specimens 
of  this  species  from  the  Oldham  district  are  somewhat  different 
in  appearance ;  they  are  shorter  antero-posteriorly  and  altogether 
more  thick-set.  The  posterior  end  is  obliquely  truncate,  and  not 
so  flattened.  I  have  figured  two  specimens  of  this  form  from-  the 
cabinet  of  Mr.  J.  Ward,  F.G.S.,  of  Longton.  This  shell  is  mimicked 
very  closely  in  North  Staffordshire  by  Anthracoptera  tumida. 
Localities. — The  Pennystone  Beds,  Coalbrookdale ;  Little  Mine 
Ironstone,  North  Staffordshire;  Black  Mine,  Middle  Coal  Measures, 
Oldham,  Lancashire. 
Antheacomya  Phillipsii.  (PI.  IX.  figs.  6,  6a,  7,  8  :  Pl.X.  fig.  27.) 
TJnio  Phillipsii,  Williamson,  Phil.  Mag.  vol.  ix.  (1836)  p.  351  (without 
description). 
TJnio  linguiformis ,  Phillips,  1839,  Murchison’s  ‘  Silurian  System,’  p.  88. 
Modiola  sp.,  Binney,  1855,  Mem.  Lit.  Phil.  Soc.  Manchester,  2nd  series, 
vol.  xii.  p.  221,  note  (without  description). 
Anthracomya  Phillipsii,  Huxley  and  Etheridge,  1865,  Cat.  Foss.  Mus. 
Pract.  Greol.  pp.  157  &  160  (without  description). 
Anthracomya  Phillipsii,  T.  Rupert  Jones,  Greol.  Mag.  for  1870,  p.  217,  pi.  ix. 
figs.  3  &  18. 
