﻿art. 
  24 
  SOUTH 
  AMERICAN 
  SNAKES 
  AMARAL 
  9 
  

  

  41. 
  PETALOGNATHUS 
  NEBULATUS 
  (Linnaeus) 
  

  

  Coluber 
  nebulatus 
  Linnaeus, 
  Syst. 
  Nat., 
  ed. 
  10, 
  vol. 
  1, 
  1758, 
  p. 
  222. 
  

   Petalognathus 
  nebulatus 
  Dumeril 
  and 
  Bibron, 
  Erp. 
  Gen., 
  vol. 
  7, 
  1854, 
  p. 
  

   464.— 
  Boulenger, 
  Cat. 
  Snakes 
  Brit. 
  Mus., 
  vol. 
  2, 
  1894, 
  p. 
  293. 
  

  

  Dutch 
  Guiana. 
  — 
  1 
  specimen, 
  No. 
  11,146, 
  collected 
  by 
  C. 
  J. 
  tier- 
  

   ing; 
  v. 
  175, 
  c. 
  90 
  pair, 
  lab. 
  7 
  (4th 
  and 
  5th), 
  postoc. 
  2; 
  chin-shields, 
  

   3 
  pairs. 
  

  

  Ecuador. 
  — 
  2 
  specimens, 
  No. 
  14,035, 
  collected 
  by 
  Dr. 
  W. 
  H. 
  Jones: 
  

   v. 
  191, 
  c. 
  70 
  pair, 
  lab. 
  7 
  (4th 
  and 
  5th), 
  postoc. 
  2; 
  chin-shields 
  3 
  

   pairs; 
  No. 
  14038, 
  collected 
  by 
  Mr. 
  Wachusett: 
  v. 
  193, 
  c. 
  79 
  pair, 
  

   lab. 
  7 
  (4th 
  and 
  5th), 
  postoc. 
  2; 
  chin-shields 
  3 
  pairs. 
  

  

  42. 
  SIBYNOMORPHUS 
  MACROSTOMUS 
  Amaral 
  

  

  Sibynomorphus 
  macrostomus 
  Amaral, 
  Journ. 
  Washington 
  Acad. 
  Sci., 
  vol. 
  14, 
  

   1924, 
  no. 
  9, 
  p. 
  200. 
  

  

  Ecuador. 
  — 
  1 
  specimen, 
  No. 
  14,047 
  (Type). 
  

  

  43. 
  SIBYNOMORPHUS 
  MIKANU 
  (Schlegel) 
  

  

  Dipsas 
  mikanii 
  Schlegel, 
  Physiogn. 
  Serp., 
  vol. 
  2, 
  1837, 
  p. 
  277. 
  

   Leptognathus 
  mikani 
  Boulenger, 
  Cat. 
  Snakes 
  Brit. 
  Mus., 
  vol. 
  3, 
  1896, 
  p. 
  

  

  453. 
  

   Leptognathus 
  peruanus 
  Boettger, 
  Kat. 
  Rept. 
  Mus. 
  Senckenberg., 
  1898, 
  

  

  pt. 
  2, 
  p. 
  128. 
  

   Sibynomorphus 
  mikani 
  Ruthven, 
  Miscell. 
  Publ. 
  Univ. 
  Michigan 
  Mus. 
  

  

  Zool., 
  vol. 
  8, 
  1922, 
  p. 
  69. 
  

  

  Ecuador. 
  — 
  7 
  specimens, 
  collected 
  in 
  Guayaquil 
  by 
  F. 
  W. 
  Goding. 
  

  

  Peru. 
  — 
  1 
  specimen, 
  collected 
  in 
  Puquiura, 
  by 
  E. 
  C. 
  Erdis, 
  in 
  June, 
  

   1915, 
  and 
  referred 
  to 
  S. 
  peruanus 
  by 
  Barbour 
  and 
  Noble. 
  4 
  

  

  The 
  examination 
  of 
  this 
  series 
  suggested 
  a 
  comparative 
  revision 
  

   of 
  the 
  species 
  S. 
  mikanii 
  and 
  S. 
  peruanus 
  (type 
  from 
  Santa 
  Ana, 
  

   Cuzco, 
  Peru) 
  which 
  Boettger 
  considered 
  a 
  valid 
  form, 
  differing 
  es- 
  

   pecially 
  in 
  coloration, 
  (belly, 
  head 
  and 
  lips), 
  number 
  and 
  disposition 
  

   of 
  upper 
  labials, 
  size 
  of 
  internasals, 
  its 
  formula 
  being: 
  sc. 
  15; 
  v. 
  

   180; 
  a. 
  1; 
  c. 
  79 
  pairs 
  plus 
  1; 
  lab. 
  8 
  (3, 
  4, 
  5); 
  temp. 
  2 
  + 
  3; 
  4 
  pairs 
  

   of 
  chin-shields, 
  anterior 
  much 
  longer 
  than 
  broad. 
  The 
  examination 
  

   of 
  the 
  specimen 
  in 
  the 
  United 
  States 
  National 
  Museum 
  and 
  another 
  

   series 
  in 
  the 
  Museum 
  of 
  Comparative 
  Zoology 
  yielded 
  the 
  following 
  

   figures 
  and 
  data: 
  

  

  <Proc. 
  U. 
  S. 
  Kat. 
  Mus., 
  vol. 
  58, 
  1920, 
  p. 
  620. 
  

  

  53649— 
  25f 
  2 
  

  

  