92 UNIVERSITY OF COLORADO STUDIES 



black, and surrounded by the ventral color. Size medium; length 

 up to three feet. 



Range of 0. doliatus, United States generally, and northern Mexico; 

 of 0. d. doliatus, Florida north to Maryland and west into Oklahoma 

 and Texas; of O. d. gentilis, Nebraska and Colorado, south into 

 Mexico, west of the Mississippi River. 



This harmless and useful snake is often mistaken for the poisonous 

 Harlequin Snake, Elaps fulvius (Linnaeus), since their color patterns 

 are of the same type and made up of the same color units. We have 

 no records of the Harlequin Snake in Colorado, although it is known 

 from northern and western Texas. The poisonous Elaps may be 

 recognized by the order of the colors, as the red band is bordered on 

 each side by a yellow band while in the harmless Ophibolus the red 

 band is bordered on each side by a black band. 



Colorado specimens. — University Museum: Boulder, July 22, 1904 (190 

 mm.), V. E. Metcalf, No. 128; Boulder, August, 1911 (245 mm.), No. 130; 

 Colorado State Historical and Natural History Museum: Yuma, June 6, 1905 (2 

 specimens, 570 and 630 mm.), Mrs. D. H. Boyes; Orchard, July 12, 1910 (skin 

 only, 340 mm. to lower jaw), Mrs. E. M. Fowle; Colorado Museum of Natural 

 History: Clear Creek, near Golden, June, 191 2 (450 mm.), alive at the museum 

 when examined by us; Agricultural College Museum: Beulah (210 mm.), H. F. 

 Wilson; State Teachers' College Museum; Weld, Larimer and Baca counties, 

 A. E. Beardsley. 



Genus PITYOPHIS Holbrook 

 Pityophis Holbrook, N. Am. Herpetology, Vol. IV, p. 7, 1842. 



Anal entire; scales keeled, in 27 to 35 rows; preoculars, i or 2; 

 maxillary teeth equal; rostral plate large and recurved between the 

 internasals ; a cartilaginous epiglottis which may be elevated vertically 

 in front of the glottis, producing a loud hissing sound when the breath 

 is expelled; large, heavy snakes. 



The Bull Snakes, genus Pityophis, are the largest of the North 

 American harmless snakes, often reaching the length of eight feet. 

 They are generally beUeved to be quite dangerous. This is perhaps 

 due to their bold disposition and angry behavior when disturbed. At 

 this time they produce a loud hissing sound which may be heard 



