REPTILES. 81 



Gratiot County. These are the only specimens from Michigan that 

 the writer has seen. There is a record in the University of Michigan 

 Museum catalog of a specimen (No. 3G9) collected by E. W. Mc- 

 Graw at Ann Arbor, but the specimen cannot now be found. 



ORDER SQUAMATA SUBORDER SERPENTES (tHE SNAKES) . 



Description: As previously stated the Michigan snakes may be 

 distinguished from the other members of the class in the state by 

 the absence of limbs, external ear openings, and movable eyelids. 

 The body is elongate and covered with scales. The scalation is as 

 follows: small imbricated smooth or keeled scales forming longi- 

 tudinal and diagonally transverse rows on the dorsal surface of the 

 body and tail. A single series of large transverse and imbricated 

 scutes on the ventral surface of the body with a somewhat larger 

 single or divided plate (anal) just in front of the anus, xl single 

 or double row of imbricated scutes on the ventral surface of the 

 tail. Large symmetrically arranged plates on the head. 



Key to the Snakes of Michigan. 



a\ No pit between the eye and nostril. Tail not terminating in a 

 rattle, 

 b^. Anal plate divided. 



c^. Dorsal scales keeled (occasioualh^ but faintly), 

 d^. Loreal plate absent, Storeria. 



e^. Oculars 1-2 S. dehayi, p. 83. 



e^ Oculars 2-2 S. occipitomaculata, p. 85. 



d". Loreal plate present. 



e^. Eostral plate greatly developed and protrud- 

 ing Heterodon pUityrhinus, p. 87. 



e-. Rostral plate normal, i. e., flattened over the 

 end of the muzzle, 

 f^ First 3-5 rows of dorsal scales smooth, 

 the rest weakly keeled, ^Zap/ie. 

 g:^. Color above black or with obscure 



blotches E. ol)soletus, p. 90. 



Color above yellowish to light brown 

 with prominent dark brown 



blotches E. pulpimis, p. 93. 



f^. Scales of all of the dorsal rows (except 

 often the first) strongly keeled. 

 11 



>5 



g'- 



