REPTILES OF THE I'ACIKIC COAST. 183 



Genus 33. BASCANION. 



Bascanion, B. & G., Cat. N. A. Kept., I't. 1, Seip., 1853, p. 9.S (type 

 constrictor); Mastkophis, H. it (I., 1. c, p. 98 (type ornatus). 



The body is very long and slender, witli long whip- 

 like tail. The head is distinct from the nock, large, 

 long, with flattened top and rounded snout. Its plates 

 are normal. The nasal plates are not united. There 

 are two (rarely one) preoculars and two postoculars. 

 Temporals are normally 2-2. A loreal is present. The 

 scales are smooth, in fifteen, seventeen, or nineteen 

 rows, usually with two (0-3) apical pits. The anal plate 

 is divided.'^ Urosteges are in two series. The eye is 

 very large, with round pupil. 



Four species are known to be Californian. Young of 

 the first tw^o are blotched, of the others, striped, 



SYNOPSIS OF SPECIES. 



a. — Scales in seventeen rows. 



b. — No distinct longitudinal light Hues. 



c. — Urosteges fewer than 100; gastroHteges fewer thau 185. 



B. constrictor vetustum. — p. 18.3. 

 c^. — Urosteges more than 100; gastrosteges more thau 190. 



B. flag-ellum frenatum. — p. 186. 

 b^. — A light liue along third aud fourth rows of scales. 



B. laterals.— p. 188. 

 a-. — Scales in fifteen rows B. taeniatum. — p. 190. 



58. — Bascanion constrictor vetustum Baird & Girard. 

 Western Yellow-bellied Racer. 



Bascanion veUistus, B. & (1., Cat. N. A. Kept., Pt. I, Serp., 1853, 



p. 97 (type locality San Jose, Calif.); Girard, U. S. Explor. 



Exped., Herp., 1858, p. Ill, pi. VIII, tigs. 1-2-19. 

 Bascanium constrictor jlaviventris. Yarrow & Hensiiaw, Surv. W. 



lOOfcb Mer., App. NN., 1878, p. 213; Yarrow, Bull. U. S. Nat. 



Mus., No. 24, 1882, p. 110 (part). 



* This plate has been found undivided in B. flagtUum and its westernmost subsiiecies 

 B. f. frenatum. 



