IV BULLETIN 187, UNITED STATES NATIONAL MUSEUM 



Family Colubridae — Continued. 



Subfamily Colubrinae — Continued. Paw 



Genus Imantodes 74 



Genus Lampropeltis 77 



Genus Leptodeira 85 



Genus Leptophis 90 



Genus Manolepis __ 92 



Genus Masticophis 92 



Genus Ninia 99 



Genus Opheodrys 100 



Genus Oxybelis 101 



Genus Oxyrhopus 103 



Genus Phyllorhynchus 103 



Genus Pituophis 105 



Genus Pliocercus 108 



Genus Procinura 111 



Genus Pseudoficimia ' 112 



Genus Pseudoleptodeira 113 



Genus Pseustes 113 



Genus Rhadinaea 115 



Genus Rhadinella 119 



Genus Rhinocheilus 120 



Genus Salvadora 121 



Genus Sibon 126 



Genus Sonora 126 



Genus Spilotes 131 



Genus Stenorrhina 132 



Genus Symphimus 133 



Genus Sympholis 134 



Genus Tantilla 134 



Genus Tantillita 142 



Genus Toluca 142 



Genus Tretanorhinus 144 



Genus Trimorphodon 145 



Genus Tropidodipsas 149 



Genus Xenodon 153 



Subfamily Natricinae 153 



Genus Adelophis 153 



Genus Natrix 154 



Genus Storeria 156 



Genus Thamnophis 158 



Family Elapidae 169 



Genus Micruroides 169 



Genus Micrurus 169 



Family Hydrophidae 176 



Genus Pelamis 176 



Family Crotalidae 177 



Genus Agkistrodon 177 



Genus Bothrops 179 



Genus Crotalus 184 



Genus Sistrurus 198 



Species inquirendae 200 



State lists 202 



Index 217 



