286 Illinois Sf(fte Lahoratorij of Natural History. 



Total length of an example from southern Illinois, 4r).r)(>; 

 tail, 11.50. 



Throughout the State. Common south. Cook Co. (Ken- 

 nicott), Galesburg, Peoria (Brendel), Normal, Urbana, Cob- 

 den, Anna. 



Formerly a common species, but it has been exterminated 

 in the better agricultural regions, and is not common at present 

 except in localities where there are extended tracts of unculti- 

 vated land to afford it retreats. The pilot snakes and this 

 species are not commonly discriminated, and accounts of the 

 habits of the black snake as frequently refer to one as to the 

 other. This is one of the largest species of our fauna, reach- 

 ing a length of seven feet or more. It is perfectly harmless, but 

 will occasionally pursue one whom it recognizes as more cow- 

 ardly than itself. It is a great coward, however, and ordinarily 

 takes to flight at the first sound of one's approach. It is an invet- 

 erate robber of birds' nests, climbing trees for this purpose with 

 great facility. Besides young birds, its food consists of frogs 

 and field mice. The form known as the Blue Racer seems to 

 to be the more common in central Illinois. 



PiTYOPHIS, HOLBR. 



Ilolbr., N. A. Ilerp., 1842, IV., p. 7. 



Bd. and Gir., Cat. N. A. llept., Pt. I., 1853, p. 64. 



Median rows of dorsal scales slightly carinated, outer rows 

 smooth, in from twenty-five to thirty-five rows. Anal plate 

 entire. Rostral plate produced upward and backward be- 

 tween the iuternasals. Two internasals. Two pairs of pre- 

 frontals or one pair; sometimes with a small intermediate extra 

 plate — the anterior frontal. Two nasals. Loreal present. One 

 or two anteorbitals. Two to five postorbitals. Includes large, 

 spotted species. 



Pityophis catenifer, Blainville. Bull Snakk. 

 V ar. catenifer. 



^'o////;*/- (Y//r////rr, JJhiinville, Nouv. Ann. .\rus. Hist. Nat., III.. 



1834, pi. 26. fiff. 2, 2a, 2b. 

 Pliiiophlscdiciifir. lid. iuul Gil., Cat. N. A. Kept., Pt. I., 1853. 



p. (W. 



