NATURAL SCIENCES OF PHILADELPHIA. 335 



Nostrils lateral ; horn-like processes over eyes. 



13. Cerastes, 

 Nostrils vertical, surrounded by several nasals ; pupil 



erect. 14. Clotho,* 



Nostrils vertical, each in a single nasal ; pupil round. 



15. Daboia, 



** Urosteges one-rowed. 

 Nostrils lateral. 16, Toxicoa, 3 1 



B. Superciliary region plated. 

 * Urosteges one-rowed. 

 Nostrils lateral. 17. Echis, 2 



** Urosteges two-rowed. 

 Top of head scaled. 18. Vipera, 2 2 



Top of head plated. 19. Pelias, 1 1 



3. ATRACTASPIDIN^. 



Fangs without external groove. Head not distinct from the body. Gape 



small. Pupil round. No lachrymal fossa. 



Head symmetrically plated : urosteges one-rowed : 

 frontal plates, two pairs. 20. Atractaspis, 1 



Head symmetrically plated : urosteges one-rowed ; fron- 

 tal plates, one pair. 21. Brachycranion, 1 1 



4. CAUSING. 



Fangs with an indistinct external groove. Head moderately distinct. Pupil 

 round. No lachrymal fossa. 

 Head symmetrically plated ; urosteges two-rowed. 



22. Cadsus, 1 1 



Total, 83 34 



1. CROTAL1NJE. . 



Hypnale Fitzinger. 

 Systema Reptjlium, 1843, p. 28. 



1. H. nepa nobis. Coluber nepa Laurenti. Spec. Synopsis Reptilium, 

 p. 97, 1768. Trigonocephalies hypnale Boie, Schlegel, et aliorum. 



Our specimens agree very nearly with the description of Trigonocephalus 

 Z a r a Gray, Brit. Mus. Catal. of Snakes, p. 15, in the narrow white vitta upon 

 the temporal region, the brown lips with one or two white spots posteriorly, the 

 white band upon the lower part of the neck, etc. ; the scales are smooth except 

 a few dorsal rows, which have traces of carina?. Dr. Gray's description is, 

 however, so brief, that we cannot, with confidence, refer them to it, the more 

 so as no subseqitent author notices its existence. Besides, Dr. Gray's species 

 was brought from Singapore. Two spec. Ceylon, Mr. Cuming. 



Trigonocephalus Oppel. 

 Rept. p. 50. 

 a. Scales carinate. Trigonocephalus. 



2. T. Blomhoffii-Boie. 



Three spec. Ningpo, Dr. McCartee. 



*It is probable that some of the species assigned by Dr. Gray to Clotho, belong more 

 properly to Cerastes. 



1859.] 



