784 13. COLUBRID 
Ceratophallus Core, Amer. Naturalist, Vol. XXVII, 1893, p. 483 (type, 
vittata). 
Diplophallus Core, 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 ) 
WeEsTERN WaTER SNAKE 
Regina valida Kennicott, Proc. Acad. Nat. Sci. Phila., 1860, p. 334 (type 
locality, Durango, Mexico); Cope, Bull. U. S. Nat. Mus., No. 32, 
1887, p. 74. 
Tropidonotus tephropleura, Cort, Proc. Acad. Nat. Sci. Phila., 1860, 
p- 341 (type locality, Cape St. Lucas). 
Tropidonotus celeno Corr, Proc. Acad. Nat. Sci., Phila. 1860, p. 341 
(type locality, Cape St. Lucas); Core, Proc. Acad. Nat. Sci. 
Phila., 1861, p. 298. 
Tropidonotus validus validus Cope, Bull. U. S. Nat. Mus., No. 1, 1875, 
p. 42; Yarrow, Bull. U.S. Nat. Mus., No. 24, 1883, p. 132; BELp- 
Inc, West Amer. Scientist, Vol. III, No. 24, 1887, p. 99. 
Tropidonotus validus celeno Core, Bull. U. S. Nat. Mus., No. 1, 1875, 
pp- 42, 93; YaRRow, Bull. U. S. Nat. Mus., No. 24, 1883, p. 1333 
Bexpinc, West Amer. Scientist, Vol. III, No. 24, 1887, p. 99. 
Tropidonotus validus tephropleura Yarrow, Bull. U. S. Nat. Mus., No. 
24, 1883, p. 133; BeLpinc, West Amer. Scientist, Vol. IIT, No. 24, 
1887, p. 98. 
