39. NATRIX 785 



Tropidonotus leberis validus Garman, Mem. Mus. Compr. Zool. Cambr., 



Vol. VIII, No. 3, pp. 28, 143. 

 Regina valida celccno Cope, Bull. U. S. Nat. Mus., No. 32, 1887, p. 74. 

 Matrix valida valida Cope, Proc. U. S. Nat. Mus., Vol. XIV, 1892, p. 670; 



Cope, Report U. S. Nat. Mus. for 1898, 1900, p. 984, figs. 258, 259. 

 hatrix valida celano Cope, Proc. U. S. Nat. Mus., Vol. XIV, 1892, p. 670; 



Cope, Report U. S. Nat. Mus. for 1898, 1900, p. 986, fig. 260. 

 Tropidonotus validus Boulenger, Cat. Snakes Brit. Mus., Vol. i, 1893, 



p. 237; GiJNTHER, Bioiogia Cent.-Amer., 1894, p. 134; Mocquard, 



Nouv. Arch. Mus. Hist. Nat., 4e Ser.,Vol. I, 1899, p. 329; Ditmars 



Reptile Book, 1907, p. 245. 

 Natrix valida Van Denburgh, Proc. Cal. Acad. Sci., Scr. 2, Vol. V, 



1895, p. 152; Van Denburgh, Proc. Acad. Nat. Sci. Phila., 1897, 



p. 464; Stejneger & Barbour, Check List N. Amer. Amph. Rept., 



1917, p. 97; Van Denburgh & Slevin, Proc. Cal. Acad. Sci., Ser. 



4, Vol. XI, 1921, pp. 52, 68; Nelson, Mem. Nat. .Acad. Sci., Vol. 



XVI, 1921, pp. 114. 115. 

 Natrix celaeno Van Denburgh, Proc. Cal. Acad. Sci., Ser. 2, Vol. V, 



1895, p. 154. 



Description. — Head distinct from neck, flat-topped, with 

 rather narrow, rounded snout, and temporal regions some- 

 times swollen. Rostral large, bounded behind by internasal, 

 anterior nasal, and first labial plates. Plates on top of head 

 are a pair of internasals, a pair of prefrontals, a long frontal, 

 supraocular of each side, and a pair of large parietals. An- 

 terior and posterior nasals distinct. One loreal. Preoculars 

 one or two, or very rarely three. Postoculars usually three, 

 sometimes two. Temporals normally one followed by two, 

 sometimes 1+3. Supralabials eight, or very rarely seven, 

 fourth and fifth reaching eye, sixth and seventh largest. 

 Infralabials usually ten, sixth largest, first pair meeting on 

 median line. Genials in two pairs, posterior longer than 

 anterior. Scales on body in 1 9 rows, all keeled except occa- 

 sionally in outer row. Anal plate divided. Gastrosteges 

 varying in number from 139 to 154. Urosteges in two 

 series of from 6S to 83. 



