﻿CHELONIA 
  AND 
  A 
  TOOTH 
  OF 
  (?) 
  ORNITHOP3IS. 
  

  

  235 
  

  

  the 
  mandible 
  of 
  L. 
  trigonieeps, 
  and 
  in 
  the 
  absence 
  of 
  any 
  evidence 
  

   to 
  the 
  contrary 
  should 
  apparently 
  be 
  referred 
  to 
  the 
  same 
  genus. 
  

   The 
  right 
  humerus 
  under 
  consideration 
  (fig. 
  3) 
  differs, 
  however, 
  

  

  Pig. 
  3. 
  — 
  Dorsal 
  Aspect 
  of 
  the 
  Right 
  Humerus 
  of 
  Lytoloma 
  cantabri- 
  

  

  aiense 
  

  

  ; 
  from 
  the 
  Cambridge 
  Greensand. 
  (Nat. 
  size.) 
  

  

  tv'Si^v, 
  

  

  g, 
  head; 
  h, 
  radial 
  process; 
  i, 
  ulnar 
  ditto; 
  e, 
  ectepicondylar 
  canal. 
  

  

  from 
  that 
  of 
  the 
  Eocene 
  Lytoloma 
  (Euclastes) 
  figured 
  by 
  M. 
  Dollo, 
  in 
  

   that 
  the 
  head 
  is 
  less 
  oblique 
  to 
  the 
  shaft, 
  and 
  the 
  radial 
  process 
  less 
  

   closely 
  connected 
  with 
  the 
  head. 
  The 
  shaft 
  has, 
  however, 
  the 
  same 
  

   marked 
  constriction 
  as 
  in 
  the 
  latter. 
  In 
  the 
  position 
  of 
  the 
  head 
  

   this 
  type 
  of 
  humerus 
  is, 
  indeed, 
  more 
  like 
  that 
  of 
  Chelone 
  than 
  of 
  

   Thalassochelys, 
  which 
  approaches 
  to 
  the 
  Eocene 
  one 
  figured 
  by 
  M. 
  

   Dollo. 
  Its 
  constricted 
  shaft 
  separates 
  it, 
  however, 
  wideJy 
  from 
  

   Chelone 
  ; 
  and 
  it 
  is 
  distinguished 
  from 
  both 
  the 
  existing 
  genera 
  by 
  

   the 
  solid 
  triangular 
  mass 
  formed 
  by 
  the 
  radial 
  process. 
  

  

  I 
  do 
  not, 
  however, 
  regard 
  these 
  slight 
  differences 
  as 
  necessarily 
  

   indicating 
  generic 
  distinction; 
  and 
  I 
  therefore 
  propose, 
  on 
  the 
  

  

  