13 



southern Cnemidophori, which can only with doubt and uncertainty 

 be maintained as a distinct form, lends still less evidence to the ex- 

 tension of the range of the southern forms. 



48. Thamnophis marciana (BAIRD & GIEARD). Two spec- 

 mens which apparently belong to this species are in the collection — 

 14040) taken by Mr. W. W. Price at Tucson, Arizona, and (4216) from 

 Tempe, Arizona, taken by Prof. W. W. Thoburn. This species is 

 closel)' connected with T. vagrans; its true status is not as ye: defin- 

 itely settled. 



Before leaving this genus I would speak a few words concerning 

 the facts noted on the species mentioned. First 1 would say a word 

 of praise to Mr. Van Denburgh, who, with the excellent collection of 

 coast Garter snakes of the Stanford University at his disposal, suc- 

 ceeded in unraveling the meshes of the described western forms, t 



Before his paper appeared there were somewhere in the neigh- 

 borhood of seventeen species and sub-species described from the 

 region his work covers. These forms are reduced to seven — five spe- 

 cies and two sub-species. 



An examination of the material used by the gentleman men- 

 tioned, together with the new material recorded above, proved tliat 

 seven tenable forms onl ■ can be recognized. The confusion caused 

 by Prof. E. D. Cope's caTlless work with this genus may be consid- 

 ered set aright as far as the Pacific coast is concerned. Though the 

 writer confidently expocts fuither material may reduce the number 

 one or two more when connecting material in the ranges — especially 

 in the Northwest — of the several forms is obtained. 



This senus is certainly the most variable of North American 

 snakes. Constant characters are apparently difficult to establish: 

 T. vagrans .sometimes has nineteen scale rows; T. elegans varies in 

 the number of rows from seventeen to twenty-one {or twenty-three).? 

 From this we will see that to identify the forms by Mr. Van Den- 

 burgh's key to species, in regard to this character, will be accompan- 

 ied with difficulties, to one unacquainted with the different forms. 

 Likewise we have T. hammondii with nine superior labials and 

 T. elegans with seven superior labials on both sides. As we have no 

 good reason for not believing that the other spe<?ies of the genus do 

 not vary as much as those which we have more specimens of, it is 

 evident that a specific key is of little value based on the scale form- 

 ula. The variation of the superior labials also weakens Mr. Van 

 DenVjurgh's key and throws most of the best distinguishing charac- 

 ters onto the color, and although I will admit that color variations 

 are received only with doubt by me, I am forced to confess that tlie 

 color seems to be the best discriminating point. And it is this great 

 variation of the scales, together with the resemblance in coloration 

 of some of the species, which suggest that the number of Pacific 

 coast forms will be further reduced when a more thorough knowl- 

 edge of our Northwest species is presented. 



FAMIl.Y. CROTALID.E. 



49. Crotalis luoifer BAIED & GIEARD. No. 1764 comes from 

 ihe Klamath River, Cal. Mr. Heller took it at Blufi' Lake, in the 

 San Bernardino Mountains, and in the Cuyamaca Mountains, San 

 Diego county, Cal Mr. Snodgrass found the species at Ontario, Oal. 



50. Crotalis confluentus SAY. Mr. W. W. Price took one of 

 these snakes (4185) at Wilcox, Cohise county, Arizona. 



51. CrotaluB mitchellii (COPE). Mr. Coolidge took an excel- 

 lent specinian at of this rare Rattlesnake at Coyote Valley, twenty- 

 five miles ea^st of Oak Grove, San Diego county, Oal. 



X Ocasional Papers Cala. Acad. Sci. , Y 1897, pp. 199-214. 

 3 Seventeen scale rows in (1754) trom Fresno, Cal. 



