﻿PACHYCOEMIDJS. 
  409 
  

  

  not 
  exceeding 
  0*055 
  in 
  a 
  specimen 
  measuring 
  0-025 
  in 
  transverse 
  

   diameter 
  where 
  the 
  vomerine 
  teeth 
  are 
  implanted. 
  Upper 
  aspect 
  

   of 
  rostrum 
  flattened, 
  almost 
  hollowed, 
  the 
  sides 
  converging 
  below 
  

   so 
  that 
  the 
  transverse 
  section 
  appears 
  triangular 
  with 
  rounded 
  

   angles 
  ; 
  surface 
  smooth 
  or 
  in 
  part 
  slightly 
  rugose. 
  

  

  Form. 
  <$r 
  Loc. 
  Cenomanian 
  (Cambridge 
  Greensand) 
  ; 
  Cambridge- 
  

   shire. 
  

  

  Not 
  represented 
  in 
  the 
  Collection. 
  

  

  Protosphyrsena 
  nitida 
  (Cope). 
  

  

  1872. 
  Erisichthe 
  nitida, 
  E. 
  D. 
  Cope, 
  Proc. 
  Acad. 
  Nat. 
  Sci. 
  Philad. 
  

   p. 
  281. 
  

  

  1874. 
  Erisichthe 
  nitida, 
  E. 
  D. 
  Cope, 
  Bull. 
  U. 
  S. 
  Geol. 
  Surv. 
  Territ. 
  

   vol. 
  i. 
  no. 
  2, 
  p. 
  42. 
  

  

  1875. 
  Erisichthe 
  nitida, 
  E. 
  D. 
  Cope, 
  Vert. 
  Cret. 
  Form. 
  West 
  (Rep. 
  

   U.S. 
  Geol. 
  Surv. 
  Territ. 
  vol. 
  ii.), 
  p. 
  217, 
  pi. 
  xlviii. 
  rigs. 
  3-8. 
  

  

  1877. 
  Erisichthe 
  nitida, 
  E. 
  D. 
  Cope, 
  Bull. 
  U.S. 
  Geol. 
  Surv. 
  Territ. 
  

  

  vol. 
  iii. 
  p. 
  821. 
  

   1890. 
  Protosphyrcena 
  nitida, 
  J. 
  Felix, 
  Zeitschr. 
  deutsch. 
  geol. 
  Ges. 
  

  

  vol. 
  xlii. 
  p. 
  278, 
  pis. 
  xii., 
  xiii., 
  pi. 
  xiv. 
  figs. 
  2-7. 
  

   1892. 
  Protosphyrcena 
  nitida, 
  A. 
  R. 
  Crook, 
  Palaeontogr. 
  vol. 
  xxxix. 
  

  

  p. 
  110. 
  

  

  Type. 
  Portions 
  of 
  skull. 
  

  

  The 
  type 
  species 
  of 
  the 
  so-called 
  genus 
  Erisichthe. 
  Rostrum 
  

   much 
  elongated, 
  slightly 
  recurved, 
  and 
  attaining 
  a 
  length 
  of 
  about 
  

   0*155 
  with 
  a 
  transverse 
  diameter 
  of 
  0*025 
  at 
  its 
  base 
  where 
  the 
  

   vomerine 
  teeth 
  are 
  implanted 
  ; 
  flattened 
  above 
  in 
  its 
  distal 
  half, 
  

   the 
  transverse 
  section 
  in 
  this 
  region 
  is 
  semicircular, 
  a 
  strong 
  angle 
  

   on 
  each 
  side 
  limiting 
  the 
  superior 
  plane, 
  while 
  the 
  section 
  at 
  the 
  

   base 
  of 
  the 
  rostrum 
  is 
  a 
  transverse 
  oval 
  • 
  the 
  flattened 
  upper 
  surface 
  

   finely 
  rugose, 
  the 
  remainder 
  ornamented 
  with 
  closely 
  arranged 
  

   longitudinal 
  ridges, 
  in 
  part 
  reticulated. 
  

  

  Form. 
  Sf 
  Loc. 
  Upper 
  Cretaceous 
  (Niobrara 
  Group) 
  : 
  Kansas, 
  U.S.A. 
  

  

  Not 
  represented 
  in 
  the 
  Collection. 
  

  

  Protosphyrsena 
  penetrans 
  (Cope). 
  

  

  1877. 
  Erisichthe 
  penetrans, 
  E. 
  D. 
  Cope, 
  Bull. 
  U.S. 
  Geol. 
  Surv. 
  Territ, 
  

  

  vol. 
  iii. 
  p. 
  822. 
  

   1890. 
  Protosphyrcena 
  penetrans, 
  J. 
  Felix, 
  Zeitschr. 
  deutsch. 
  geol. 
  Ges. 
  

  

  vol. 
  xlii. 
  p. 
  297, 
  pi. 
  xiv. 
  fig. 
  1. 
  

   1892. 
  Protosphyrcena 
  penetrans, 
  A, 
  R. 
  Crook, 
  Paheontogr. 
  vol. 
  xxxix. 
  

  

  p. 
  109. 
  

  

  Type. 
  Rostrum. 
  

  

  Rostrum 
  much 
  elongated 
  and 
  attaining 
  a 
  length 
  of 
  about 
  0*15 
  

  

  