Vor. III] VAN DENBURGH AND SLEVIN—ARIZONAN REPTILES 427 
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No. 2 3 Urosteges & a 3 3 ee 
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33656 183 24 (1+) 15—16 | 17—17 | 2—2 |} 3—3 | 1—1 
79.—Crotalus tigris Kennicott 
This species seems to be quite rare in southern Arizona. 
We secured only one specimen (No. 34274) near the steam 
pump about eighteen miles north of Tucson, May 8, 1912. 
This one was caught about four p. m. just as it was entering 
a hole in the ground. Crotalus atrox was common in the 
same locality. ; 
The scale rows are 25, gastrosteges 165, anal entire, uro- 
steges 20, supralabials 14-14, infralabials 14-15, preoculars 
2-2, postoculars 2-3, loreals 1-1. There are forty dark bars 
on the body and five on the tail. 
80.—Crotalus confluentus Say 
We refer to this species one specimen (No. 17531) from 
Cave Creek, Maricopa County. The coloration in life was 
greenish. In alcohol it is pale and resembles C. atrox. The 
bands on the tail are pure black on a light ground as in C. 
atrox. On the posterior portion of the body the rhombs be- 
come cross-bars. The lower surfaces are white, unmarked. 
The head markings are somewhat faded, but in position and 
character are those of C. confluentus, with which species it 
agrees in scale characters. 
It has scales in 25 rows, gastrosteges 177, anal entire, 
urosteges 19, two divided, supralabials 16-16, infralabials 16~ 
