40. THAMNOPHIS 809 
Tropidonotus sirtalis var. collaris GarMAN, Mem. Mus. Comp. Zool., 
Vol. XIII, No. 3, 1883, p. 25. 
Eutenia collaris Cope. Proc. Am. Philos. Soc., Vol. XXII, 1884, p. 173; 
Ducks, La Naturaleza, Ser. 2, Vol. I, 1888, p. 127, pl. XIII, fig. 
16. 
Eutenia cyrtopsis collaris Corr, Proc. U. S. Nat. Mus., Vol. XIV, 1892, 
p- 657. 
Eutenia aurata Corr, Proc. U. S. Nat. Mus., Vol. XIV, 1892, p. 659 
(type locality, Lake Valley, southern New Mexico). 
Tropidonotus ordinatus var. eques BoULENGER, Cat. Snakes Brit. Mus., 
Vol. I, 1893, p. 209. 
Eutenia eques Cope, Report U. S. Nat. Mus. for 1898, 1900, p. 1049; 
Brown, Proc. Acad. Nat. Sci. Phila., 1901, p. 25; Dirmars, Reptile 
Book, 1907, p. 230, pls. LXVI, fig. 8, LX-XI, fig. 1. 
Eutenia eques collaris Cope, Report U. S. Nat. Mus. for 1898, 1900, 
p- 10st. 
Eutenia eques aurata Cope, Report U. S. Nat. Mus. for 1898, 1900, 
p- 1052. 
Thamnophis cyrtopsis STEJNEGER, Proc. U. S. Nat. Mus., Vol. XXV, 
1902, p. 155. 
Eutenia sirtalis dorsalis Cope, Report U. S. Nat. Mus. for 1898, 1900, 
p- 1076. 
Thamnophis eques, RuTHVEN, Bull. Am. Mus. Nat. Hist., Vol. XXIII, 
1907, p. 588; Rutuven, Bull. U. S. Nat. Mus., No. 61, 1908, p. 
158; Stone, Proc. Acad. Nat. Sci. Phila., 1911, p. 232; Van DeEn- 
BURGH & SLEvIN, Proc. Cal. Acad. Sci., Ser. 4, Vol. III, p. 419; 
STeEJNEGER & Barzour, Check List N. Amer. Amph. Rept., 1917, 
p- 101; Van DensurcH & Stevin, Proc. Cal. Acad. Sci., Ser. 4, 
Vol. VIII, No. 6, 1918, p. 204. 
Description—Head distinct from neck, flat-topped with 
narrow, rounded snout. Temporal regions sometimes 
swollen in old individuals. Eye moderate. Rostral plate 
large, bounded behind by internasal, anterior nasal, and first 
labial plates. Plates on top of head, a pair of internasals, 
a pair of prefrontals, a frontal, supraocular of each side, 
and a pair of parietals. Anterior and posterior nasals dis- 
tinct. One loreal. One or rarely two preoculars. Post- 
oculars normally three, rarely two or four. Temporals 
