426 KANSAS UNIVERSITY SCIENCE BULLETIN. 



It feeds upon rats, mice, birds, young rabbits, and other small 

 animals. 



The following are the dimensions and scutellation of six 

 specimens in the museum of Kansas University : 



I have examined specimens from Douglas, Brown, Franklin, 

 Riley and Wabaunsee counties. 



Crotalus confluentus Say. 



Confluent or Prairie Rattlesnake, sometimes called Massasauga. 



Crotalus confluentus Say, Long's Exped. Rocky Mts., II, 1823, p. 48. 



Crotalus confluentus Stejneger, Rept. U. S. Nat. Mus. for 1893, 1895, p. 440. 



Crotalus confluentus confluentus and pulverulentus Cope, Crocodilians, Liz- 

 ards, and Snakes, 1898, p. 1170. 



Fig. 39. 

 Crotalus confluentus Say. 



Scales in 23-27 rows. First and second rows faintly or not 

 keeled ; a few dorsal rows strongly keeled, Superciliaries large, 

 projecting above the eye. Prefrontals small, overlapping the 

 superciliaries. Internasals smaller than in horridus. Between 

 the internasals two horn-like scales and several smaller scales ; 

 all the remainder of the top of the head covered with scales. 

 Rostral higher and slightly wider than in horridus. The ante- 

 rior nasal is almost square. Posterior nasal ear-shaped. Nare is 

 in the anterior part of it. One or two small loreals. Four rows 

 of scales between the eye and the labials. Supralabials 13-16. 



