SNAKES. 63 



Generally a vertebral row of more or less distinct spots; a 

 lateral row of white, dark-edged spots ; no longitudinal line. 



a. Adult and young, Tunis. From Mr. Eraser's Collection. 



b. Half-grown. Algiers. From Paris. 



e. Nearly half-grown. Tangiers. From Mr. Fraser's Collec- 

 tion. 



Var. B. chersoides. 



Natrix chersoides et ocellata, Wagl. ^ Spix, Serp. Bras, 

 t. 10, 11; Syst. Amph. p. 1/9. Tropidonotus viperinus, var., 

 Schleg. Ess. ii. p. 326. Tropidonotus chersoides, part., Dum. Sf- 

 Bibr. p. 562. 



Back with two yellowish longitudinal lines. 



d. Adult. Tangiers. From Mr. Fraser's Collection. 



e. Half-growTi. Tunis. From Mr. Fraser's Collection. 



3. Tropidonotus hydrus. 



Coluber hydrus, Pall. Zoogr. Rosso- Asiat. iii. p. 36 ; Rathke 

 in Mem. del' Acad. St. Petersb. iii. pi. 1. f. 1-7. Hydrus caspius, 

 Schneid. Amph. Tropidonotus tantalus et T. gracilis, Eichwald, 

 Zool. iii. p. 173. Coluber reticulatus, Mmetries. Tropidonotus 

 hydrus, Nordmann, Voy. dans la Russie Merid. par A. Demidoff, 

 Rept. pi. 10; Eichwald, Fauna Caspio-Caucas. t. 24. f. 1-3; 

 Dum. Sf Bibr. vii. p. 564. 



Scales in nineteen rows ; anal bifid ; eight upper labials, only 

 the fourth reaching the orbit ; three (two) anterior, four posterior 

 oculars. Blackish ash above, sometimes with more or less regular 

 black spots ; belly whitish, towards the middle black-dotted and 

 black. 



a, b. Adult and half-grown. Europe. Presented by Arthur 

 Russell, Esq. 



c. Adult. Italy. Presented by J. J. Bianconi as T. gabinus. 



d. Adult. Odessa. 



€. Adult. Euphrates Expedition. Two anterior oculars. 



/. Adult. India ? From Mr. Warwick's Collection. 



g. Young. Euphrates Expedition. Two anterior oculars. 



4. Tropidonotus quincunciatus. 



Hydrus piscator et palustris, Schneider, Hist. Nat. Amphib. 

 p. 247 & 249. Show, Gen. Zool. p. 568 & 569. Russell, Ind. 

 Serp. ii. 1. 14, 15^, 20, 33. Enhydris piscator et E. palustris, Latr. 

 Rept. iv. p. 203. Coluber anastomosatus and C. braminus, Daud. 



