1903.] NATURAL SCIENCES OF PHILADELPHIA. 287 



type locality, which have been founded upon snakes belonging to the 

 genus from this region, or whose range has been extended to enter it. 

 Those admitted here are printed in capitals : 



Coluber parietalis Say (1823). Missouri river near Council Bluffs. 



Coluber infernalis Blain. (1835). California. 



Tropidonotus ordinoides B. and G. (1852). Puget Sound. 



Tropidonotus concinnus Hallow. (1852). Oregon. 



EuT^NiA pickeringi B. and G. (1853). Puget Sound. 



EuT^NiA LEPTOCEPHALA B. and G. (1853). Puget Sound. 



Eutcenia dorsalis B. and G. (1853). Rio Grande, Texas. 



EuT^NiA ELEGANS B. and G. (1853). El Dorado county, Cal. 



EuTJENiA VAGRANS B. and G. (1853). Cahfornia. 



Tropidonotus trivittatus Hallow. (1853). California. 



Eutcenia couchi Kenn. (1857). Pitt river, Shasta county, Cal. 



Eutcenia atrata Kenn. (1860). California. 



Eutcenia cooperi Kenn. (1860). Washington (?). 



EuT^NiA HAMMONDi Kcuu. (1860). San Diego county, Cal. 



E. sirtalis tctratcenia Cope (1875). Pitt river and Puget Sound. 



Eutcenia henshawi Yarrow (1884). Walla Walla, Wash. 



EUT.ENIA BiscuTATA Cope (1883). Klamath Lake, Oregon. 



E. elegans plutonia Cope (1892)=type of E. henshawi Yarr. 



E. elegans brunnea Cope (1892). Fort Bid well, Cal. 



E. elegans lineolata Cope (1892). No definite type. 



E. inferncdis inferncdis Cope (1892). Fresno and San Francisco. 



E. infernalis vidua Cope (1892)=types of E. atrata Kenn. 



E. sirtalis trilineata Cope (1892). Port Townsend, Ore. 



These names, twenty-three in number, appear to me to be reducible 

 to three species, two of which present three forms each, sufficient in num- 

 ber and constant enough in character, or so associated with a restricted 

 area of distribution as to compel recognition as subspecies; or seven 

 forms in all,^ the special features of which are capable of being arranged 

 in a key which will cover all cases but the few anomahes upon which 

 individual judgment is required. 



A. — Scales in 21 rows ; upper labials 8 : 



a. — Body moderately stout; head and eye rather small; posterior 

 chin-shields equal or very little longer than anterior 

 (E. elegans) : 



^ Mr. Van Denburgh admits the same forms, but like values are not attached 

 to them in all cases. Mr. Boulenger reduces them still further to five. As the 

 only purpose of this paper is to analyze the various type specimens, no attempt 

 is made to give references bej-ond tlie original descriptions. 



