HERPETOLOGY OF ZUNI MOUNTAINS — GEHLBACH 313 



(1956, table 2.7), a series of prairie rattlers from the Zunis approxi- 

 mates C. V. nuntius in six of eight meristic characters: number of 

 subcaudal scales and tail rings in males, nmnber of ventral scales 

 and tail rings in females, and total scale row and body blotch counts 

 (table 9). Of the remaining two, only the female subcaudal count 

 favors assignment to C. v. mridis; the male ventral count is intermedi- 

 ate. Further indications of affinity with C. v. nuntius are the number 

 of midtail scale rows (11-15, x 12.3±0.21) and ground color, which 

 is predominately tan or brown rather than greenish. 



Fifteen adults average 653 mm. in total length. The largest is 

 926 mm. and is the only decidedly greenish individual collected or 

 observed. A female, 620 mm. total length, gave birth to six young, 

 measuring 212-228 (x 219) mm., on September 21, 1957. Klauber's 

 (1956, table 4.1) data for average size at bhth indicate that these 

 young are approximately intermediate between C. v. viridis and 

 C. V. nuntius. 



It is not surprising to note the light-tan to yellow ground color of 

 C. V. concolor in a few Zuni specimens. This feature has been reported 

 in San Juan County, New Mexico (Gehlbach, 1956, p. 371). Inter- 

 grades between C. v. viridis, C. v. nuntius, and C. v. concolor probably 

 occur in the San Juan Basin, but this is difficult to demonstrate since 

 C. V. concolor is distinguishable from C. v. nuntius only by means of 

 coloration. 



Two prairie rattlers, UMMZ 121413 from Canyon de Chelly 

 National Monument, Apache County, Arizona, and UMMZ 121412 

 from White Canyon, San Juan County, Utah, are pertinent to this 

 discussion. Both are small adults, 540 and 485 mm. in total length 

 respectively, alilve in their pinkish-brown coloration. The Arizona 

 specimen differs by having white borders around its anterior dorsal 

 blotches and head markings and a dark-brown stripe across the snout. 

 The Utah snake could be C. v. nuntius x C. v. concolor in view of its 

 color, pattern, and locality, but several of the larger Zuni specimens 

 also lack white-bordered markings. Legler (1960, p. 182) states that 

 dorsal markings are obliterated gradually with age in C. v. concolor. 

 Apparently C. v. viridis does not penetrate northwestern New Mexico 

 and adjacent Arizona and Utah as mapped by Klauber (1956, fig. 2.6). 



Prairie rattlesnakes inhabit a ^vide range of Zuni environments. 

 While many individuals were taken on lava flows and in the short-grass 

 and saltbush-sage associations, a smaller number were collected in the 

 Roughlands Life Belt. One was found in the ponderosa pine associa- 

 tion of the lower Montane Life Belt. C. viridis seemingly was 

 outnumbered by C. atrox in the lower, more open grassland, especially 

 that dominated by cholla cactus. Juveniles were uncommon in the 

 Plains Life Belt, suggesting that they might be born in the vicinity 



