TABLE OF CONTENTS. VII 



The Elegans group — Continued. Page. 



Ilammondi 133 



Desrription 133 



Habits and habitat relations 133 



Range 133 



Variation 136 



Affinities 137 



Elegans 1 38 



Descrijjtion 138 



Habits and liabitat relations 138 



Range ' 140 



Variation 143 



Affinities 146 



Ordinoides 147 



Description 147 



Habits and habitat relations 148 



Range 148 



Variation , 151 



Affinities 156 



Conclusion 157 



The Sirtalis group (eques, sumichrasti, parietalis, concinnus, sirtalis) 158 



Eques 158 



Description 158 



Habits and habitat relations 1 60 



Range 100 



Variation 162 



Affinities 164 



Sumichrasti 1 64 



Description 1 04 



Range 1 65 



Affinities 100 



Parietalis 106 



Description 1 00 



Habits and habitat relations ' ]()7 



Range 1 ()7 



Variation 108 



Affinities 172 



Concinnus 173 



Description 1 73 



Habits and habitat relations 173 



Range 174 



Variation 174 



Affinities 176 



Sirtalis 170 



Description 176 



Habits and habitat relations 177 



. Range 179 



Variation 181 



Affinities 186 



Conclusion 186 



Discussion of origins 1 87 



Method of evolution of the forms 192 



The garter-snakes as material for experimental investigation 194 



Bibliography 195 



