292 



COLTTBETDiB. 



distance from the end of the snout, shorter than the parietals ; 

 loreal much longer than deep; two postoeulars ; temporals 1 + 2; 

 seven upper labials, third and fourth entering the eye ; four lower 

 labials in contact with the anterior chin-shielda, which are longer 

 than the posterior. Scales in 19 rows, more or less distinctly 

 keeled in the ischiadic region. Ventrals 168-206 ; anal divided ; 

 subcaudals 34-49. Black above ; sides and belly red, with black 

 cross bars or alternating spots. 



Total length 1020 millim. ; tail 150. 



Mississippi Valley and eastwards. 



a, b, c. S (V. 170 ; C. 46) New Orleans. M. Salle [C.]. 

 & $ (V. 189, 191 ; 0. 

 86, 36). 



d. $ {V. 199 ; C. 37), skin N. America. 

 & skeleton. 



e. Yg. (V. 172 ; C. 34). N. America. Mrs. Drummond [P.]. (Typo 



of -F. drummondi.) 



f. Yg. (V. 168; C. ?). N. America. Sir R. Murchison [P.]. 



"^ 109. PETALOGNATHUS. 



Dipsas, part., ScMeff. Phys. Serp. ii. p. 2.57 (1837). 



Petalognathus, Dum. ^ Bibr. Mem. Ac. Sc. xxiii. 1853, p. 466, and 



Erp. Gen. vii. p. 463 (1854). 

 Leptognathus, part„ Giinth. Cat. Col. Sn. p. 177 (1858) ; Jan, 



Elenco sist. Ofid. p. 100 (1863) ; Cope, Proc. Ac. Philad. 1868, 



p. 107. 



Fig. 21. 



Skull of Petdlognathus nebulatm. 



MaxUlary short, with 15 or 16 teeth, which gradually decrease 

 in size ; posterior mandibular teeth gradually decreasing in size. 

 Head short and thick, -very distinct from neck ; eye large, with 



