TABLE OF CONTENTS. VII 



The Elegans group — Continued. 



Hammondi , ^ oo 



Description ^ oo 



Habits and habitat relations 1 03 



?^"g^: - .'^---^^'-''^-^^"^''^'"■':;: 133 



Variation ,qp 



Affinities ,07 



Ele-^ans ,00 



-^ , . loo 



Description ^00 



Habits and habitat relations 230 



I^ange ...y.^.^.... 140 



Variation , , o 



Affinities , ^ „ 



Ordinoides -..j 



Description ^ .« 



Habits and habitat relations 24g 



Range ....... ug 



Variation it-i 



. „ . . 151 



Affinities -.cf. 



Conclusion ic-. 



„,. . 10/ 



1 he birtahs group (eques, sumichrasti, parietalis, concinnus, sirtalis) 158 



^^"!f----; '.'.v. 158 



Description ^ c-q 



Habits and habitat relations jgn 



Range " ^ " " ' " ^^^ 



Variation , „„ 



Affinities , ^ - 



Sumichrasti ' -,„. 



-^ . . 164 



Description , „ , 



^^^: ;;;;;;;;;;;;;;:::::::::::::::::::: les 



Affinities , „ „ 



Parietalis • ,„„ 



-r- . . »■ loo 



Description , ^„ 



Habits and habitat relations jgy 



Range ; !!!!!!!!!' 167 



Variation -, -.„ 



Affinities -.^^ 



Concinnus " ,„„ 



Description , „„ 



Habits and habitat relations ^73 



Range ^ ^ -'''''!!!!"'"!" ' 174 



Variation , „ . 



Affinities i-„ 



a- . T 176 



Sirtalis . 



T~, . . 17b 



Description , „ „ 



Habits and habitat relations j^y 



Range -.."!'!'"!""!!!! 179 



Variation , „, 



Affinities -> „„ 



Conclusion , „„ 



Discussion of origins ,0- 



Method of evolution of the forms 299 



The garter-snakes as material for experimental investigation I94 



Bibliography ^^^ 



