79. HETEEODON. 153 



Total length 285 millim. ; tail 45. 

 Southern Brazil. 



a-b. d (V. 138 ; C. 33) Cio Cahy, near S. Dr. H. v. Ihering [0.]. 

 & hgr. (V. 133 ; 0. 27). Joao de Monte 

 Negro. 



3. Lystrophis semicinctus. 



Heterodon semicinctus, Bum. Sf Bibr. vii. p. 774 (1854) ; Jan, Arch. 



Zool. Anat. Phys. ii. 1863, p. 224, a-nd Icon. O^n. 48, pi. iii. fig. 5 



(1876). 

 pulcher, Jan, II. ce. p. 222, Icon. 11, pi. iv. fig. 1 (1865). 



Frontal as long as broad, shorter than its distance from the end 

 of the snout, as long as the parietals ; usually an azygous shield 

 separating the praefrontals ; one or two prse- and two postoculars ; 

 temporals 1+2; eight upper labials (exceptionally seven), fourth 

 and fifth entering the eye ; four or five lower labials in contact 

 with the anterior chin-shields ; posterior chin-shields small. Scales 

 in 21 rows. Ventrals 153-173 ; anal divided ; subcaudals 25-41. 

 End of taU rounded off. Above with black cross bars disposed in 

 pairs, the interspace between the two yellow, that between the pairs 

 red ; the red scales, and sometimes also the yeUow ones, with a black 

 spot or a black edge ; head variegated with black ; a black band 

 between the eyes ; beUy black, usually yellow on the sides. 



Total length 660 millim. ; tail 80. 



Uruguay, Bolivia, Argentina, Northern Patagonia. 



a. c? (V. 156 ; 0. 30). Uruguay. 



6. $ (V. 153; 0.26). Rio de Cordova, E. Fielding, Esq. [P.]. 



Argentina. 



c. cf (V. 162 ; 0. 36). Catamarca. Lord Dormer [P.]. 



d-e. Yg. (V. 159, 154 ; Argentina. E. W. White, Esq. [C.]. 



C. 33, 30). 



f-cf. 2 (V. 160; 0. 27) Patagonia. 



&hgr. (V. 162; 0.25). 



79. HETERODON. 



Heterodon, Latrdlle, Sist. Rept. iv. p. 32 (1800) ; Baird Sr Gir. 



Cat. N. Am. Bept. p. 51 (1853) ; Cope, JProe. U.S. Nat. Mm. xiv. 



1892, p. 642. 

 Heterodon, part., Schleg. Phys. Serp. ii. p. 96 (1837) ; Bum. Sr Bibr. 



JBrp. Gin. vii. p. 764 (1854) ; Giinth. Cat. Col. Sn. p. 82 (1858) ; 



Jan, Arch. Zool. Anat. Phys. ii. 1863, p. 218 ; Bocourt, Miss. 8c. 



Mex., Bept. p. 603 (1886). 



Maxillary very short, shorter than the ectopterygoid, with 6 to 

 11 teeth, followed, after an interspace, by a pair of strongly enlarged 

 fangs ; mandibular teeth subequal. Head scarcely distinct from 

 neck ; snout very short, projecting, cuneiform ; rostral very large, 

 trihedral, with sharp A-shaped edge ; eye moderate, with round 



