﻿462 
  Berry 
  — 
  A 
  Sail 
  Fish 
  from 
  the 
  Virginia 
  Miocene. 
  

  

  with 
  an 
  open 
  obtuse 
  sinus. 
  This 
  sinus 
  becomes 
  more 
  angular 
  

   as 
  it 
  is 
  traced 
  forward 
  until 
  at 
  one-third 
  of 
  the 
  distance 
  forward 
  

   it 
  is 
  acutely 
  angular, 
  from 
  which 
  point 
  forward 
  its 
  sides 
  

   gradually 
  become 
  confluent. 
  The 
  ventral 
  surface 
  is 
  convex, 
  show- 
  

   ing 
  traces 
  of 
  a 
  lateral 
  suture 
  separating 
  the 
  marginal 
  \ 
  from 
  

   the 
  median 
  \ 
  of 
  the 
  lateral 
  diameter. 
  There 
  is 
  a 
  pronounced 
  

   median 
  suture 
  more 
  or 
  less 
  distinct 
  for 
  the 
  whole 
  length 
  of 
  

   the 
  rostrum. 
  This 
  broadens 
  out 
  in 
  the 
  proximal 
  third 
  of 
  the 
  

   rostrum 
  to 
  form 
  a 
  broad 
  shallow 
  palatine 
  sinus. 
  There 
  are 
  no 
  

   traces 
  of 
  dentigerous 
  surfaces. 
  Each 
  premaxillary 
  is 
  traversed 
  

   by 
  a 
  nutrient 
  canal 
  which 
  at 
  the 
  base 
  are 
  large 
  and 
  elliptical 
  

   with 
  their 
  longer 
  diameters 
  oblique 
  and 
  forming 
  an 
  angle 
  of 
  

   about 
  40 
  degrees. 
  Ventrally 
  they 
  approach 
  within 
  about 
  2 
  mm 
  

   of 
  one 
  another 
  and 
  their 
  maximum 
  and 
  minimum 
  diameters 
  

   are 
  12 
  mm 
  and 
  6*5 
  mm 
  respectively. 
  Medianly 
  and 
  lying 
  above 
  

   the 
  premaxillary 
  canals 
  is 
  a 
  central 
  oblanceolate 
  foramina 
  

   about 
  7 
  mm 
  in 
  height 
  and 
  with 
  a 
  maximum 
  transverse 
  diameter 
  

   of 
  l 
  mm 
  dorsad. 
  

  

  The 
  component 
  elements 
  of 
  the 
  rostrum 
  are 
  completely 
  

   coossified 
  and 
  indicate 
  a 
  fish 
  of 
  considerable 
  size. 
  

  

  Vertical 
  Transverse 
  

  

  ( 
  1/4 
  distance 
  from 
  base 
  26 
  mm 
  36 
  

  

  Diameter 
  of 
  rostrum 
  \ 
  1/2 
  23-5 
  mm 
  ' 
  33 
  

  

  ( 
  3/4 
  18-5 
  mm 
  28 
  

  

  mm 
  

   mm 
  

   mm 
  

  

  The 
  accompanying 
  text 
  figures 
  1/3 
  natural 
  size 
  show 
  the 
  

   dorsal 
  (fig. 
  1) 
  and 
  ventral 
  (fig. 
  2) 
  aspects 
  of 
  the 
  rostrum 
  and 
  

   transverse 
  sections 
  (tigs, 
  la, 
  lb, 
  1<?, 
  Id) 
  at 
  the 
  points 
  indicated. 
  

  

  Occurrence. 
  — 
  Calvert 
  Formation. 
  Tar 
  Bay, 
  James 
  River, 
  

   Prince 
  George 
  County, 
  Virginia. 
  

  

  The 
  fragments 
  from 
  the 
  Ashley 
  Hiver 
  marls 
  which 
  Leidy* 
  

   described 
  as 
  Xijphias 
  robustus 
  and 
  appears 
  to 
  have 
  considered 
  

   as 
  Eocene 
  in 
  age, 
  and 
  which 
  Hayf 
  referred 
  to 
  Istiophorus 
  and 
  

   considered 
  Post-pliocene 
  in 
  age 
  is 
  similar 
  in 
  general 
  form 
  but 
  

   smaller 
  and 
  with 
  two 
  dentigerous 
  bands 
  separated 
  by 
  a 
  groove. 
  

   The 
  age 
  of 
  the 
  South 
  Carolina 
  form 
  is, 
  of 
  course, 
  uncertain 
  

   since 
  the 
  Ashley 
  marls 
  contain 
  so 
  many 
  mechanically 
  mixed 
  

   fossils 
  of 
  various 
  ages. 
  As 
  I 
  have 
  remarked 
  elsewhere, 
  this 
  

   may 
  be 
  true 
  of 
  the 
  Virginia 
  specimen 
  since 
  the 
  Calvert 
  is 
  

   underlain 
  by 
  the 
  Aquia 
  Eocene. 
  In 
  both 
  cases, 
  however, 
  the 
  

   Istiophorus 
  rostra 
  are 
  associated 
  with 
  teeth 
  of 
  the 
  Miocene 
  

   Physeter 
  vet 
  us 
  (Leidy). 
  

  

  I. 
  aniiquus 
  (Leidy 
  %) 
  from 
  the 
  Eocene 
  of 
  New 
  Jersey 
  is 
  

  

  * 
  Leidy, 
  J., 
  in 
  Holmes' 
  Post-pliocene 
  Fossils 
  of 
  South 
  Carolina, 
  p. 
  119, 
  

   pi. 
  27, 
  figs. 
  3-5, 
  1869. 
  

  

  + 
  Hay. 
  0. 
  P., 
  U. 
  S. 
  Geol. 
  Survey 
  Bull. 
  179, 
  p. 
  402, 
  1902. 
  

   % 
  Leidy, 
  J., 
  Proc. 
  Acad. 
  Nat. 
  Sci. 
  Phila., 
  vii, 
  p. 
  397, 
  1855. 
  

  

  