290 fllinois State Laboratory of Natural Hif^tory. 



Elaphis obsoletus, Say. Pilot Snake, Black Snake. 

 Var. obsoletus. 



('i,l alitor o/>.vo/f ^/.s-, Say, Long's Kxpeil. to Rocky Mts., 1823, 1., 



p. 140. 

 (ilaorgia nbsolrta, Bd. and Gir., Cat. N. A. llept., Pt. I., 1853, p. 158. 

 Scotophis ohsot&iiis, Kenn., Proc. Acad. Nat. Sci. Phila., 18(50, 



p. 330. 

 Co/uber oljsolefiis, subsp. dhso/rfiis and '■oii/iiiis,Da,\-is and Rice, 



Bull. 111. State Lab. Nat. Hist., I., No. 5, 1883, pp. 36, 37; 



Bull. Chicago Acad. Sci., 1883. 

 I^JIapJi is obsoti'ftis,^. G-drm-du, Mem. Mus. Comp. ZoiU., 1883, pp. 



54, 151, pi. 4, fig. 2. 



Var. lindheimeri. 



^ajtnphis liiidhf^hittril, Bd. and Gir. Cat. N. A. Rept. Pt. I., 1853, 



p. 74. 

 Hcotophis tniorii'i, Bd. and Gir., 1. c, p. 157. 

 (Coluber emoryi and C. lUidlieinicrl, Davis and Rice, Ball. State 



Lab. Nat. Hist., L, No. 5, 1883, p. 3(5; Bull. Chicago Acad. Sci., 



1883. 

 Elaphis obs()Mtfs,va,i\ UiKllnhncrii, S. Crarman, Mem. Mus. Corap. 



Zool., 1883, pp. 54, 152. 



Body elongate, slender, slightly compressed, ventral sur- 

 face flattened. Head large, elongate, clearly separated by the 

 narrower neck. Only the median dorsal scales carinate. Ros- 

 tral plate wide, excavated below. Prefrontals very large. 

 BVontal pentagonal, nearly or quite as wide in front as long. 

 One large anteorbital. Two or three postorbitals. Eight su- 

 pralabials, the middle of the eye above the line of juncture of 

 the fourth and fifth. Thirteen infralabials, the sixth and 

 seventh or fifth and sixth largest. Dorsal scales in from twenty- 

 five to twenty-nine rows, the two or three outer rows of each 

 side smooth, the carina? of remaining rows becoming more 

 prominent above. Ventrals 217-23*.). Subcaudals 72-85. 



Color above brown or black with a silken gloss, or a gray 

 ground color, and black or brown dorsal and lateral blotches. 

 Beneath, straw-yellow in the young, with stjuarish or elongate 

 blackish blotches, mostly confined to the sides in front, but 

 gradually fusing toward the tail and giving a uniform dark 

 slate-color on the under side of the latter. In adults most of 

 the ventral surface is dark slate or black; in all stages oti the 



