﻿art. 
  28 
  SKULL 
  OF 
  ZARHACHIS 
  FLAGELLATOR 
  KELLOGG 
  3 
  

  

  Horizon. 
  — 
  The 
  specimen 
  was 
  discovered 
  and 
  excavated 
  by 
  Nor- 
  

   man 
  H. 
  Boss 
  on 
  December 
  30, 
  1923. 
  The 
  jagged 
  extremity 
  of 
  the 
  

   rostrum 
  was 
  found 
  protruding 
  from 
  a 
  layer 
  of 
  greenish 
  sandy 
  clay 
  

   about 
  8 
  feet 
  above 
  the 
  beach 
  at 
  a 
  point 
  less 
  than 
  50 
  feet 
  from 
  the 
  end 
  

   of 
  the 
  cliff 
  north 
  of 
  the 
  Boy 
  Scout 
  camp. 
  Shattuck's 
  zones 
  6-8 
  are 
  

   not 
  clearly 
  differentiated 
  at 
  this 
  point 
  and 
  the 
  specimen 
  came 
  from 
  

   one 
  of 
  these 
  three 
  zones. 
  

  

  SKULL 
  

  

  Dorsal 
  view. 
  — 
  As 
  mentioned 
  in 
  the 
  preceding 
  paper, 
  2 
  the 
  arrange- 
  

   ment 
  of 
  the 
  bones 
  which 
  comprise 
  the 
  dorsal 
  surface 
  of 
  the 
  brain 
  case 
  

   corresponds 
  in 
  a 
  general 
  way 
  with 
  the 
  skull 
  of 
  the 
  Chinese 
  porpoise, 
  

   Lipotes 
  vexillifer, 
  now 
  living 
  in 
  Tung 
  Ting 
  lake 
  and 
  its 
  tributaries. 
  

   There 
  are 
  a 
  number 
  of 
  rather 
  obvious 
  differences, 
  as, 
  for 
  instance, 
  the 
  

   development 
  of 
  a 
  high 
  crest 
  on 
  the 
  extremity 
  of 
  each 
  supraorbital 
  

   process, 
  the 
  projection 
  of 
  the 
  ascending 
  processes 
  of 
  the 
  premaxillae 
  

   behind 
  the 
  nasals, 
  the 
  presence 
  of 
  a 
  pair 
  of 
  crescentic 
  orifices 
  for 
  

   nerves 
  on 
  the 
  posterior 
  walls 
  of 
  the 
  "blow 
  holes," 
  the 
  outward 
  curva- 
  

   ture 
  of 
  the 
  vomerine 
  trough 
  to 
  form 
  a 
  portion 
  of 
  the 
  dorso-anterior 
  

   wall 
  of 
  each 
  nasal 
  passage, 
  and 
  the 
  prolongation 
  of 
  the 
  anterior 
  

   extremity 
  of 
  the 
  zygomatic 
  process 
  and 
  the 
  postorbital 
  projec- 
  

   tion 
  of 
  the 
  supraorbital 
  process 
  so 
  that 
  they 
  overlap. 
  In 
  its 
  general 
  

   features, 
  the 
  skull 
  of 
  Zarhachis 
  is 
  characterized 
  chiefly 
  by 
  the 
  ex- 
  

   ceedingly 
  long 
  and 
  slender 
  rostrum 
  which 
  comprises 
  more 
  than 
  

   five-sixths 
  of 
  the 
  total 
  length 
  of 
  the 
  skull, 
  the 
  "upended" 
  supra- 
  

   orbital 
  processes 
  of 
  the 
  frontals, 
  and 
  the 
  pair 
  of 
  crescentic 
  orifices 
  on 
  

   the 
  posterior 
  walls 
  of 
  the 
  nasal 
  passages 
  below 
  the 
  relatively 
  thick 
  

   nasals, 
  peculiarities 
  that 
  are 
  most 
  noticeable 
  when 
  contrasted 
  with 
  

   skulls 
  of 
  other 
  known 
  porpoises. 
  Since 
  the 
  rostrum 
  was 
  fully 
  described 
  

   in 
  the 
  previous 
  paper, 
  there 
  is 
  no 
  necessity 
  for 
  a 
  detailed 
  discussion 
  

   of 
  this 
  part 
  of 
  the 
  skull. 
  

  

  All 
  of 
  the 
  brain 
  case 
  posterior 
  to 
  the 
  nasal 
  passages 
  and 
  the 
  "up- 
  

   ended" 
  supraorbital 
  processes 
  was 
  missing 
  from 
  the 
  first 
  skull 
  

   (Cat. 
  No. 
  10485, 
  U.S.N.M.). 
  A 
  small 
  fragment 
  of 
  bone 
  which 
  

   appeared 
  to 
  be 
  a 
  portion 
  of 
  the 
  vertex 
  was 
  found 
  alongside 
  of 
  this 
  

   skull 
  and 
  it 
  was 
  so 
  placed 
  in 
  the 
  restoration 
  3 
  of 
  the 
  brain 
  case. 
  

   The 
  brain 
  case 
  of 
  the 
  second 
  skull 
  (pi. 
  1) 
  is 
  in 
  a 
  fair 
  state 
  of 
  preserva- 
  

   tion 
  and 
  the 
  description 
  that 
  follows 
  has 
  been 
  prepared 
  in 
  the 
  form 
  

   of 
  a 
  supplement 
  to 
  the 
  preceding 
  paper. 
  

  

  Behind 
  the 
  antorbital 
  notches, 
  the 
  maxillae 
  push 
  back 
  over 
  the 
  

   frontals 
  and 
  expand 
  into 
  relatively 
  thin 
  horizontal 
  plates. 
  The 
  outer 
  

   border 
  of 
  each 
  maxilla 
  is 
  deflected 
  obliquely 
  upward 
  and 
  inward 
  to 
  

   conform 
  with 
  the 
  curvature 
  of 
  the 
  "upended" 
  crestlike 
  portion 
  of 
  the 
  

  

  » 
  Kellogg, 
  R., 
  A 
  fossil 
  porpoise 
  from 
  the 
  Calvert 
  formation 
  of 
  Maryland. 
  Vroc. 
  U. 
  S 
  Nat. 
  Mus., 
  vol. 
  03, 
  

   publ. 
  2482, 
  pp. 
  1-39, 
  pis. 
  1-18. 
  March 
  26, 
  1924. 
  

   » 
  Kellogg, 
  R., 
  Idem, 
  pi. 
  1. 
  

  

  