708 13. COLUBRID& 



Pityophis sayi btllona YARROW & HENSHAW, Ann. Rep. Chief of Engi- 

 neers for 1878, Surv. W. looth Merid., Appendix NN, 1878, p. 213 

 (part); YARROW, Bull. U. S. Nat. Mus., No. 24, 1883, p. 106 (part). 



Pityophis catcnifcr catenifer BROWN, Proc. Acad. Nat. Sci. Phila., 1901, 

 p. 53 (part). 



Pituophii catenifer catenifer GRINNELL & CAMP, Univ. Cal. Publ. Zool., 

 Vol. 17, No. 10, 1917, p. 193 (part); STEJNEGER & BARBOUR, Check 

 List N. Amer. Amph. Rept., 1917, p. 85; VAN DENBURGH & SLEVIN, 

 Proc. Cal. Acad. Sci., Ser. 4, Vol. IX, 1919, p. 211, pis. XI, XII, 

 fig. I (part); VAN DENBURGH, Proc. Cal. Acad. Sci., Ser. 4, Vol. X, 

 No. i, 1920, p. 13. 



Description. Head rather flat-topped or rounded, with 

 snout projecting and rather narrow. Temporal regions not 

 swollen. Rostral plate very large, prominent, not very 

 narrow but often recurved between internasals on top of 

 snout; bounded behind by internasal, anterior nasal, and 

 first labial plates. Plates on top of head are a pair of inter- 

 nasals, four, two, one, three, five, six, or eight prefrontals, 

 a frontal, supraocular of each side, and a pair of parietals. 

 Anterior and posterior nasals usually distinct, sometimes 

 united. Loreal usually elongate. One or usually two pre- 

 oculars, and two to five, usually three, postoculars. Tips 

 of some labials often cut off, forming suboculars or loreals. 

 Seven to 10, usually eight, and 10 to 14, usually 13 or 12, 

 inferior labials, next to last superior and sixth or seventh 

 inferior usually largest in its series, fourth or fifth superior 

 usually reaching eye, first pair of inferior meeting on median 

 line. Temporals in first row varying from two to six, 

 usually four or three, very variable. Two pairs of genials, 

 anterior much larger than posterior. Scales on body in 29 

 to 33 rows, usually 3 1 , keeled except in a varying number 

 (about three to 10) of rows on each side. Anal plate not 

 divided. Gastrosteges varying in number from 200 to 230, 

 males having from 207 to 230, females from 200 to 230. 



