F»ROCEEDINGS 



OF THE 



CALIFORNIA ACADEMY OF SCIENCES 



Fourth Series 



Vol. VIII, No. 6, pp. 181-270, pis. 7-17 October 18, 1918 



VI 



THE GARTER-SNAKES OF WESTERN NORTH 



AMERICA 



JOHN VAN DENBURGH 

 Curator, Department of Hcrpetology 



AND 



JOSEPH R. SLEVIN 

 Assistant Curator, Department of Herpetology 



TABLE OF CONTENTS 



PAGE 



Introductory remarks 182 



List of species and subspecies 183 



Key to the various forms 184 



The Sirtalis group 185 



General discussion , 186 



Thamnophis sirtalis parietalis 190 



Thamnophis sirtalis concinnus 192 



Thamnophis sirtalis infernalis 198 



Thamnophis eques 204 



The Elegans group 206 



General discussion 207 



Thamnophis ordinoides ordinoides 215 



Thamnophis ordinoides atratus 224 



Thamnophis ordinoides elegans 235 



Thamnophis ordinoides vagrans — 240 



Thamnophis ordinoides biscutatus 245 



Thamnophis ordinoides couchii 251 



Thamnophis ordinoides hammondii 256 



Thamnophis marcianus 261 



Thamnophis megalops ■^. 263 



Thamnophis angustirostris 264 



Bibliography ,^r:;'7.Trr-rr?-*=5u,„j. 267 



J^^\X«50n lan ?■ r^.^^J/S. October 18. 1918 



