I. Typhlops vermicularis, Eryx jaculus 144 II. Tropidonotus natrix and Vars. cettii and persa 152 III. Tropidonotus tessellatus, T. viperinus and var. aurolineatus 160 IV. Zamenis gemonensis and vars. persica and viridiflavus 170 V. Zamenis gemonensis, var. caspius, Z. dahlii, Z. hippocrepis 176 VI. Coluber quatuorlineatus and var. sauromates, C. dione 182 VII. Coluber longissimus, C. leopardinus and var. quadrilineatus 188 VIII. Coluber scalaris 194 IX. Coronella austriaca 196 X. Coronella girondica, Contia modesta 202 XI. Coelopeltis monspessulana, Macroprotodon cucullatus, Tarbophis iberus, T. fallax 208 XII. Vipera ursinii, V. renardi, V. berus 220 XIII. Vipera aspis, V. latastii 240 XIV. Vipera lebetina, V. ammodytes, Ancistrodon halys 250 ------------------------------------------------------------------------ THE SNAKES OF EUROPE INTRODUCTION CHAPTER I DEFINITION AND CLASSIFICATION Snakes, _Ophidia_--regarded by some authorities as an order of the class _Reptilia_, by the author as a sub-order of the order _Squamata_, which includes besides the Lizards, _Lacertilia_, the Chameleons, _Rhiptoglossa_, and the extinct _Dolichosauria_ and _Mosasauria_--may be defined as greatly elongate scaly Reptiles without limbs, or with mere vestiges of the hind pair, without movable eyelids, without ear-opening, with elongate, deeply forked tongue retractile into a basal sheath, with transverse vent and paired copulatory organs, and with the two halves of the lower jaw independently movable, connected at the symphysis by an elastic ligament. The latter character alone distinguishes them from all Lizards, but no single Lizard possesses all the others in combination. In their most highly developed form these Reptiles are adapted for rapid reptation and for swallowing prey much exceeding their own calibre; hence the bones of the skull, on which a prehensile function devolves, are loosely attached to the cranium by ligamentous elastic tissue, or articulated in such a manner as to permit a wide buccal expansion; whilst the absence of a sternum and the mobile attachment of the ribs allow a corresponding dilatation of the body as the prey descends into the digestive canal.