SNAKES OF THE GENUS PITUOPHIS O 



GenuB PITUOPHIS Holbrook 



Coluber Linnaeus, Systema naturae, ed. 10, vol. 1, p. 216, 1758 (type, con- 

 strictor Linnaeus). 



Pituophis Holbrook, North American herpetology, vol. 4, p. 7, 1842 (type. 

 Coluber melanoleucus Daudin). 



Churchillia Baird and Girard, Reptiles, in Expedition to the Valley of the 

 Great Salt Lake of Utah (Stansbury), p. 350, 1852 (type, bellona Baird and 

 Girard) . 



Epiglottophis Cope, Amer. Nat., vol. 25, p. 157, 1891 [type, Spilotes deppei 

 (Dum^ril and Bibron)]. 



Description. — The genus Pituophis of Holbrook, established in 

 1842 upon the form Coluber melanoleucus of Daudin (1803, vol. 6, 

 p. 409), belongs to the family Colubridae. It may be diagnosed as 

 follows: Maxillary teeth solid, 14 to 18 in number, without a diastema, 

 the anterior ones sHghtly longer, and decreasing in size posteriorly; 

 mandibular teeth 16 to 22, the anterior ones slightly larger than the 

 posterior; head only shghtly distinct from the neck; eye large, pupil 

 round; scales keeled, with the exception of the several most ventral 

 rows on either side, and with apical pits ; maximum number of dorsal 

 scales varying from 27 to 37, but mostly 29, 31, or 33; anal plate entire; 

 caudals in two series; tail relatively short; hemipenes slightly bilobed 

 with calyces and spines, sulcus spermaticus simple. 



The body is rather stout, being pronouncedly so in the four sub- 

 species of melanoleucus and in sayi sayi, somewhat so in sayi affinis, 

 and comparatively slender in the other forms of the genus, particu- 

 larly those of the deppei group — deppei, jani, and lineaticollis. The 

 head is only shghtly distinct from the neck. In the subspecies of 

 sayi and particularly in the subspecies of melanoleucus, the snout is 

 rather pointed, m correlation with the elongated rostral, and in these 

 forms the upper jaw protrudes considerably beyond the lower. In 

 forms with a low, broad rostral, such as vertebralis, the subspecies of 

 catenijer, and the three forms of the deppei group, the snout is blunt 

 and almost square, and protrudes only shghtly beyond the lower jaw. 

 The tail is relatively short, and forms as httle as 0.100 of the total 

 length in specimens of sayi, which form shows the smallest average 

 length for the genus— 0.122 of the total length. The greatest propor- 

 tionate length attained in the genus is 0.185 of the total length in a 

 specimen of c. catenijer, and the greatest average length in any form 

 is 0.161 in c. annectens. 



A single rostral and frontal are present (fig. 1). The rostral varies 

 in shape from very long and narrow in the subspecies of melanoleucus 

 (fig. 2), moderately long m sayi sayi, only slightly longer than broad 

 in sayi affinis (fig. 3) and occasional specimens of catenijer deserticola, 

 to as broad as, or slightly broader than, long in the other forms of 

 the genus (figs. 4 and 5). It penetrates from a slight fraction to all 

 the distance between the internasals. The mternasals, supraoculars, 



