Hurter — Herpetology of Missouri. 209 



82. Sistrurus catenatus Rafinesque. Prairie Rattle- 

 snake. Massasauga. 



Crotalinus catenatus, Crotalus tergeminus, Crotalus massasaugus, Cro- 

 talophorus tergeminus, Crotalophorus catenatus catenatus, Crotalo- 

 phorus massasaiigus, Crotalophorus kirtlandi, Caudisona tergemina, 

 Sistrurus catenatus catenatus. 



Description. — Rostral high, narrow, broader near the lower edge. 

 Canthus rostralis pronounced. Two internasals, triangular, anterior 

 margin convex, the posterior concave, the outer margin raised. Two 

 prefrontals, the outer margin also raised. Frontal pentagonal, often 

 broken in several shields (three). Superciliaries large. Parietals 

 broad, rounded posteriorly. Nasal two, with nostril between, which is 

 very small. Loral irregular in shape. Preoculars 2-3, long, the upper 

 reaching nearest to the internasals. About four postorbitals and as 

 many suborbitals. Upper labials 10-13. Lower labials 12-15. Head 

 moderately wide, neck contracted. Body short and stout. Tail about 

 one-ninth of total length. Rattle small. Dorsal rows of scales 25, 

 keeled except the two outer rows on each side, which are smooth. Ven- 

 trals 136-153. Anal entire. Subcaudals 21 to 31, entire, with only 

 about six posterior plates divided. 



Color. — Above brown, with about 30-36 deep chestnut-brown dorsal 

 blotches, blackish externally and with yellowish-white margins. Three 

 lateral series of brown blotches, which alternate with the dorsal ones 

 The upper series is generally much paler. A narrower band of yellowish- 

 white from the post-nasal below the orbit to the angle of the mouth. 

 There is also a grayish band from eye to eye over the anterior half of 

 the superciliaries and frontal; a dark brown band on the cheeks from 

 the eye to the neck, followed above and on the occiput by a light gray- 

 ish band and between these is a long brown blotch, reaching also to 

 the neck. Beneath the color is blackish brown and yellowish. The 

 end of the tail in newly born is whitish yellow. Sometimes the snakes 

 are of a uniform black all over. (S. kirtlandii.) 



Size. — Total length 777 mm.; rattle 39 mm. Newly born are about 

 135 mm. long. 



Habitat. — From Michigan to Wisconsin, south to Ne- 

 braska, Kansas, Missouri, Illinois, Indiana, and Ohio. 

 Missouri localities : — St. Charles, Lewis, Randolph, and 

 Warren Counties. In Illinois, West Prairie near Mitchell, 

 Madison County. 



Habits. — So far I have only found the Massasauga at 

 West Prairie, Madison Co., 111., and at Dardenne Prairie, 

 St. Charles Co., Mo. Both of these places are inundated 



