784- 13. COLUBRIDJE 



Ceratophallus Cope, Amer. Naturalist, Vol. XXV' II, 1893, p. 483 (type, 



vittata). 

 Diplophallus Cope, .Amer. Naturalist, XXVII, 1893, p. 483 (type, 



piscator). 



The body is not very elongate, fairly thick, with moder- 

 ately long tapering tail, and head large and distinct from 

 neck. The head plates are normal, two internasals, two pre- 

 frontals, a frontal, supraoculars and a pair of parietals being 

 present. Two nasals. Preoculars one, two or rarely three. 

 Postoculars two to four. The temporals usually are 1+2, 

 or 1+3. A loreal is present. The scales are keeled, have 

 two scale-pits, and are arranged in from 19 to 23 rows. The 

 anal plate is divided. Urosteges are in two series. The eye 

 is moderate or large, with round pupil. Maxillary teeth 

 generally longer posteriorly, without grooves. A large num- 

 ber of species are known from Europe, Asia, Africa, and 

 America, only one occurs in the area included in this work. 



179. Natrix valida (Kennicott) 



Western Water Snake 



Retina valida Kennicott, Proc. Acad. Nat. Sci. Phila., i860, p. 334 (type 

 locality, Durango, Mexico); Cope, Bull. U. S. Nat. Mus., No. 32, 



1887, p. 74. 



Tropidonotus tephropkura. Cope, Proc. .Acad. Nat. Sci. Phila., i860, 



p. 341 (type locality, Cape St. Lucas). 

 Tropidonotus celceno Cope, Proc. .Acad. Nat. Sci., Phila. i860, p. 341 



(type locality, Cape St. Lucas); Cope, Proc. Acad. Nat. Sci. 



Phila., 1861, p. 298. 

 Tropidonotus validus validus Cope, Bull. U. S. Nat. Mus., No. i, 1875, 



p. 42; Yarrow, Bull. U. S. Nat. Mus., No. 24, 1883, p. 132; Belo- 



iNG, West Amer. Scientist, Vol. Ill, No. 24, 1887, p. 99. 

 Tropidonotus validus ceUno Cope, Bull. U. S. Nat. Mus., No. i, 1875, 



pp. 42, 93; Yarrow, Bull. U. S. Nat. Mus., No. 24, 1883, p. 133; 



Belding, West Amer. Scientist, Vol. Ill, No. 24, 1887, p. 99. 

 Tropidonotus validus tephropkura Yarrow, Bull. U. S. Nat. Mus., No. 



24, 1883, p. 133; Belding, West Amer. Scientist, Vol. Ill, No. 24, 



1887, p. 98. 



