﻿2 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.67 
  

  

  The 
  Calvert 
  formation 
  of 
  Maryland 
  has 
  yielded 
  a 
  rather 
  large 
  

   number 
  of 
  porpoises 
  and 
  in 
  the 
  main 
  these 
  species 
  have 
  their 
  nearest 
  

   affinities 
  with 
  those 
  in 
  the 
  Tortonian 
  stage 
  of 
  Europe. 
  A 
  few 
  of 
  

   them 
  appear 
  to 
  have 
  no 
  counterparts 
  in 
  the 
  European 
  stages 
  or 
  at 
  

   least 
  none 
  have 
  been 
  described 
  and 
  one 
  of 
  these 
  is 
  Zarhachis. 
  With- 
  

   out 
  entering 
  into 
  a 
  discussion 
  of 
  the 
  fauna 
  as 
  a 
  whole, 
  it 
  is 
  sufficient 
  

   to 
  observe 
  in 
  the 
  present 
  connection 
  that 
  Zarhachis 
  appears 
  to 
  

   represent 
  a 
  highly 
  specialized 
  aberrant 
  type 
  whose 
  family 
  allocation 
  

   is 
  more 
  or 
  less 
  a 
  matter 
  of 
  personal 
  opinion 
  in 
  the 
  light 
  of 
  available 
  

   data. 
  If 
  it 
  is 
  desirable 
  to 
  associate 
  this 
  porpoise 
  with 
  other 
  genera, 
  

   it 
  must 
  be 
  done 
  with 
  the 
  understanding 
  that 
  it 
  is 
  merely 
  a 
  matter 
  

   of 
  convenience. 
  That 
  Zarhachis 
  exhibits 
  certain 
  characters 
  in 
  com- 
  

   mon 
  with 
  Inia, 
  Lipotes, 
  and 
  Platanista, 
  there 
  can 
  be 
  no 
  doubt, 
  but 
  

   whether 
  they 
  arose 
  from 
  one 
  or 
  three 
  types 
  of 
  toothed 
  whales 
  can 
  

   not 
  be 
  demonstrated 
  from 
  the 
  specimens 
  now 
  known. 
  According 
  

   to 
  our 
  present 
  knowledge, 
  Zarhachis 
  represents 
  a 
  type 
  which 
  can 
  

   not 
  be 
  referred 
  to 
  any 
  of 
  the 
  recognized 
  families 
  of 
  toothed 
  whales, 
  

   unless 
  the 
  limits 
  of 
  these 
  families 
  be 
  redefined. 
  A 
  natural 
  grouping 
  

   of 
  some 
  of 
  the 
  South 
  American 
  Miocene 
  porpoises 
  is 
  not 
  possible 
  

   at 
  present 
  because 
  of 
  the 
  lack 
  of 
  adequate 
  data 
  on 
  the 
  construction 
  

   of 
  their 
  skulls. 
  The 
  ancestry 
  of 
  the 
  Zarhachis 
  type 
  of 
  porpoise 
  is 
  

   completely 
  unknown 
  at 
  present. 
  No 
  fossil 
  porpoises 
  with 
  this 
  type 
  

   of 
  skull 
  have 
  been 
  described 
  from 
  the 
  Miocene 
  formations 
  of 
  Europe. 
  

   For 
  this 
  reason 
  there 
  can 
  be 
  little 
  doubt 
  but 
  that 
  it 
  represents 
  a 
  

   migrant 
  from 
  some 
  other 
  region, 
  probably 
  the 
  south 
  Atlantic, 
  which 
  

   became 
  associated 
  with 
  more 
  widely 
  distributed 
  types 
  during 
  the 
  

   latter 
  part 
  of 
  the 
  Miocene 
  period. 
  

  

  The 
  skull 
  of 
  Zarhachis 
  is 
  modified 
  in 
  many 
  ways, 
  as 
  will 
  be 
  noted 
  in 
  

   the 
  descriptive 
  portions 
  of 
  this 
  and 
  the 
  preceding 
  paper. 
  For 
  the 
  

   purpose 
  of 
  bringing 
  into 
  stronger 
  relief 
  the 
  characters 
  of 
  this 
  porpoise, 
  

   it 
  is 
  necessary 
  to 
  compare 
  them 
  carefully 
  with 
  living 
  river 
  porpoises. 
  

   The 
  morphological 
  characters 
  involved 
  in 
  the 
  construction 
  of 
  the 
  

   skull 
  will 
  form 
  the 
  main 
  subject 
  of 
  this 
  paper. 
  

  

  ZARHACHIS 
  FLAGELLATOR 
  Cope 
  

  

  Specimen. 
  — 
  Cat. 
  No. 
  10911, 
  division 
  of 
  vertebrate 
  paleontology, 
  

   United 
  States 
  National 
  Museum. 
  The 
  brain 
  case 
  and 
  the 
  proximal 
  

   portion 
  of 
  the 
  rostrum 
  arc 
  represented; 
  the 
  lachyrmals, 
  jugals, 
  

   periotics. 
  tympanies, 
  and 
  bones 
  of 
  the 
  inner 
  ear 
  are 
  missing. 
  Frag- 
  

   ments 
  of 
  three 
  ribs 
  were 
  found 
  near 
  this 
  skull. 
  

  

  Locality. 
  — 
  The 
  occurrence 
  of 
  this 
  specimen 
  is 
  as 
  follows: 
  Near 
  

   latitude 
  38° 
  38' 
  45" 
  N., 
  and 
  longitude 
  76° 
  32' 
  W., 
  on 
  the 
  western 
  

   shore 
  of 
  Chesapeake 
  Bay, 
  approximately 
  3% 
  miles 
  south 
  of 
  Chesa- 
  

   peake 
  Beach, 
  Calvert 
  County, 
  Mel. 
  Shown 
  on 
  Patuxent 
  quadrangle 
  

   or 
  Patuxent 
  folio. 
  No. 
  152, 
  United 
  States 
  Geological 
  Survey. 
  

  

  