274 Illinois State Lahoratonj of Nqtiiral History. 



Body moderately slender, tapering towards the extremities. 

 Head small, not much wider than the neck. Tail rather short. 

 All the dorsal scales carinate, Rostral low and broad, dis- 

 tinctly excavated below. Parietals very large. Frontal 

 elongate, pentagonal. A single ( !) nasal plate on each side, 

 obliquely grooved below the nostril. Two anteorbitals. Two 

 postorbitals. Seven or eight supralabials; the fifth and sixth 

 largest. Ten infralabials; fourth and fifth largest. Dorsal 

 rows nineteen; the scales of the outer row of each side less 

 strongly carinate than the others, and about as wide as long. 

 Ventrals 15()-178. Subcaudals 54-*)') pairs. Anal divided. 

 Tail about two tenths the length of the body. 



Color above brown, with a pale brown dorsal stripe about 

 three scales wide: on each side of this stripe a wide brown or 

 gray band edged with blackish, and about five scales wide; and 

 outside these on each side a straw-colored band occupying 

 the three outer rows of scales. Edges of the outer dorsal rows 

 and sides of the abdominal scutes black, producing on each 

 side of the abdomen a zigzag line. Beneath straw-color, 

 uniform, or with a median dusky band beneath the tail, and be- 

 fore the vent a series of blackish spots. 



Total length, 81.75; tail, 5.50. 



Throughout the State. Cook county (Kennicott), Normal, 

 Pekin, Champaign. 



In the original description of this species the number of 

 dorsal rows of scales is given as twenty. Illinois examples 

 have nineteen without exception, as far as I know. Besides 

 the differences of color, this species differs from R. leberis in 

 the number of ventral and subcaudal scutes, and in the length 

 of the tail as compared with that of the body. 



Ventrals, 1 73. Subcaudals, 65. Total length, 27.25; tail, 

 4.75. 



A^entrals, 15S. Subcaudals, 54. Total length, 31.75; tail, 

 5.50. 



Ventrals, 156. Subcaudals, 58. Total length, 26.75; tail, 

 ■5.25. 



Ventrals, 1<)0. Subcaudals. 61. Total length, 14; tail, 2.50. 



