﻿0. 
  C. 
  Marsh 
  — 
  Affinities 
  of 
  Hesperomis. 
  34, 
  

  

  Art. 
  XXXIV. 
  — 
  The 
  Affinities 
  of 
  Hesperomis 
  ; 
  by 
  

   O. 
  C. 
  Marsh. 
  

  

  In 
  the 
  autumn 
  of 
  1870, 
  I 
  discovered 
  in 
  the 
  Cretaceous 
  of 
  

   western 
  Kansas 
  the 
  remains 
  of 
  a 
  very 
  large 
  swimming 
  bird, 
  

   which 
  in 
  many 
  respects 
  is 
  the 
  most 
  interesting 
  member 
  of 
  the 
  

   class 
  hitherto 
  found, 
  living 
  or 
  extinct. 
  During 
  the 
  following 
  

   year, 
  other 
  specimens 
  were 
  obtained 
  in 
  the 
  same 
  region, 
  and 
  

   one 
  of 
  them, 
  a 
  nearly 
  perfect 
  skeleton, 
  I 
  named 
  Hesperomis 
  

   regalis* 
  In 
  subsequent 
  careful 
  researches, 
  extending 
  over 
  

   several 
  years, 
  I 
  secured 
  various 
  other 
  specimens 
  in 
  tine 
  preser- 
  

   vation, 
  from 
  the 
  same 
  horizon 
  and 
  the 
  same 
  general 
  region, 
  

   and 
  thus 
  was 
  enabled 
  to 
  make 
  a 
  systematic 
  investigation 
  of 
  the 
  

   structure 
  and 
  affinities 
  of 
  the 
  remarkable 
  group 
  of 
  birds 
  of 
  

   which 
  Hesperomis 
  is 
  the 
  type. 
  The 
  results 
  of 
  this 
  and 
  other 
  

   researches 
  were 
  brought 
  together 
  in 
  1880, 
  in 
  an 
  illustrated 
  

   monograph. 
  f 
  

  

  In 
  the 
  concluding 
  chapter 
  on 
  Hesperomis, 
  I 
  discussed 
  the 
  

   affinities 
  of 
  this 
  genus, 
  based 
  upon 
  a 
  careful 
  study 
  of 
  all 
  the 
  

   known 
  remains. 
  Especial 
  attention 
  was 
  devoted 
  to 
  the 
  skull 
  and 
  

   scapular 
  arch, 
  which 
  showed 
  Struthious 
  features, 
  and 
  these 
  

   were 
  duly 
  weighed 
  against 
  the 
  more 
  apparent 
  characters 
  of 
  

   the 
  hind 
  limbs, 
  that 
  strongly 
  resembled 
  those 
  of 
  modern 
  

   diving 
  birds, 
  thus 
  suggesting 
  a 
  near 
  relationship 
  to 
  this 
  group, 
  

   of 
  which 
  Golymbus 
  is 
  a 
  type. 
  In 
  summing 
  up 
  the 
  case, 
  I 
  

   decided 
  in 
  favor 
  of 
  the 
  Ostrich 
  features, 
  and 
  recorded 
  this 
  

   opinion 
  as 
  follows 
  : 
  

  

  "The 
  Struthious 
  characters, 
  seen 
  in 
  Hesperomis, 
  should 
  

   probably 
  be 
  regarded 
  as 
  evidence 
  of 
  real 
  affinity, 
  and 
  in 
  this 
  

   case 
  Hesperomis 
  would 
  be 
  essentially 
  a 
  carnivorous, 
  swimming 
  

   Ostrich." 
  (Odontornithes, 
  p. 
  114.) 
  

  

  This 
  conclusion, 
  a 
  result 
  of 
  nearly 
  ten 
  years' 
  exploration 
  and 
  

   study, 
  based 
  upon 
  a 
  large 
  number 
  of 
  very 
  perfect 
  specimens 
  

   and 
  a 
  comparison 
  with 
  many 
  recent 
  and 
  extinct 
  birds, 
  did 
  not 
  

   meet 
  with 
  general 
  acceptance. 
  Various 
  authors 
  who 
  had 
  not 
  

   seen 
  the 
  original 
  specimens, 
  or 
  made 
  a 
  special 
  study 
  of 
  any 
  

   allied 
  forms, 
  seem 
  to 
  have 
  accepted 
  without 
  hesitation 
  the 
  

   striking 
  adaptive 
  characters 
  of 
  the 
  posterior 
  limbs 
  as 
  the 
  key 
  

   to 
  real 
  affinities, 
  and 
  likewise 
  put 
  this 
  opinion 
  on 
  record. 
  

   The 
  compilers 
  of 
  such 
  knowledge 
  followed 
  suit, 
  and 
  before 
  

   long 
  the 
  Ratite 
  affinities 
  of 
  Hesperomis 
  were 
  seldom 
  alluded 
  

   to 
  in 
  scientific 
  literature. 
  

  

  * 
  This 
  Journal, 
  vol. 
  iii. 
  p. 
  56, 
  January; 
  and 
  p. 
  360, 
  May, 
  1872. 
  

   ■{•Odontornithes: 
  a 
  Monograph 
  on 
  the 
  Extinct 
  Toothed 
  Birds 
  of 
  North 
  America. 
  

   4to, 
  34 
  plates, 
  Washington, 
  1880. 
  

  

  