SNAKES. 27 



series of large blackish spots, alternate with smaller ones on the 

 side. 



a. Adult. Algiers. From M. Parzudaki's Collection. 

 h. Half-grown : very bad state. North Africa. 



2. Ablabes, Dum. 8f Bibr. 



Body rather elongate and slender ; head moderate, rather de- 

 pressed, with flat crown ; rostral moderate ; two nasals, nostril 

 between them (in A. modesta united) ; one loreal, one or two an- 

 terior, two posterior oculars. Scales smooth, elongate, in thirteen 

 to nineteen rows. All teeth equal, smooth. Generally a collar. 

 United States; Africa; Asia. 



Ablabes, sp., Enicognathus, sp., Dum. Sf Bibr. vii. p. 304. 

 Calamaria, sp., Coroneila, sp., Herpetodryas, sp.. Schlep. Ess. ii. 

 pp. 39, 50, 194. Lycodon, sp.. Gray, Indian Zoology. Homalo- 

 soma, sp., Wagl. Syst. Amph. p. 191. Coluber, sp., auct. prior. 



1. Ablabes modestus. 



Coroneila modesta, Martin, Proc. Zool. Soc. 1838, p. 82. 

 ?Tyria argonauta, Eichw. Faun. Caspio-Caucas. p. 114. t. 26. 

 f. 1, 2. 



Scales in seventeen rows; upper labials seven, third and 

 fourth touching the eye. Olive ; crown of head black (some- 

 times only dark olive) ; suture of occipitals lighter ; neck with 

 a black (sometimes only dark olive) collar; beneath uniform 

 whitish. 



a-d. Adult. Xanthus. 



e-z. Adult and half-grown. Xanthus. Presented by Sir C. 

 Fellows. 



a. Many specimens. Half-grown and young. Xanthus. 

 /3, 7. Young. Euphrates Expedition. 



b. Young. Ruins of Nineveh. Presented by — Loftus, Esq. 

 f . Adult. Xanthus. From the Haslar Collection. 



Especially adult specimens exhibit, instead of the black marks, 

 the head and collar only dark olive-coloured, and they may then 

 be very easily confounded with younger individuals of Zamenis 

 atrovirens ; but they may be distinguished by the number of 

 scales and upper labials, as well as by the dentition. Moreover, 

 A. modestus is the only species of the genus having only one 

 nasal. 



c2 



