170 OP HID I A. 



whitish, and generally much altered by a protracted immersion in 

 alcohol. Two double black rings may be observed upon the tail, the 

 tip of which is reddish. The abdomen, between the black rings, is 

 unicolor. 



Loc. Collected at Eio de Janeiro, Brazil. 



GENUS CERBERUS, Cuv. 



GEN. CHAR. Cephalic plates small. Nostrils and eyes on the upper 

 surface of the head ; eyes rather small. Labials large and elevated, 

 though not entering into the orbit. Dorsal scales lanceolated and 

 carinated. Abdominal scutellae large; preanal one subdivided. 

 Subcaudal scutellae disposed upon a double series. 



SYN. Cerberus, Cuv. Regn. Anim. 2d ed. II, 1829, 81. BUM. & BIBE. Erpet. gen. 

 VII, n, 1854, 977. 



OBSERV. There is but one well-known species of this genus. Future 

 investigations may bring to light others, either so far unobserved, or 

 else not distinguished from the following one. 



CERBERUS BOAEFORMIS, Dum. & Bibr. 

 (Plate VIII, figs. 8-11.) 



SPEC. CHAR. Color above deep grey or brown, with transverse black 

 bands or bars. A black vitta upon the sides of the head and neck. 

 Beneath yellowish, with black blotches. 



SYN. Elaps boaeformis, SCHN. Hist. Amph. II, 1801, 301. 

 Eurria schne.ideriana, BAUD. Hist. Nat. Rept. V, 1803, 281. 

 Python boaeformis, MERE. Tent. Syst. Amph. 1820, 89. 

 Cerberus obtusatus, FITZ. Neue Class. Rept. 1826, 55. 

 C. cinereus, CANTOE, Proc. Zool. Soe. Lond. 1839, 54. 

 C. russelii, FITZ. Syst. Rept. I, 1843, 25. 

 C. boaeformis, DUM. & BIBR. Erp. gen. VII, n, 1854, 978. 



Homalopsis schneiderii, SCHLEG. Ess. Phys. Serp. I, 1837, 171, & II, 1837, 341, 

 PI. xm, figs. 6 & 7. 



H. rhynchops, CANTOE, Journ. Asiat. Soc. XVII, 1847, 94. 



