SNAKES OF THE GENUS PITUOPHIS 23 



Table 1. — Synopsis of the forms of the genus Pituophis — Continued 



Form 



Number of spots 



Body 



Tail 



Teeth 



Mandi- 

 bular 



Maxil- 

 lary 



Pala- 

 tine 



Ptery- 

 goid 



Shape of rostral 



Num- 

 ber of 

 speci- 

 mens 

 exam- 

 ined 



affinis- 



anneetens 



catenifer 



deppei. 



deserticola 



jani 



lineaticoUis — 



todingi -.. 



melanoUucus. 

 mugitus 



Tuthveni. 

 sayi 



Berlebratis. 



Total. 



33-68 



55-92 

 44-94 

 32-44 

 43-74 

 21-25 



9-19 



14-36 

 12-31 



9-16 

 11-22 



7-10 



Stripes anteriorly, 

 annuli in midre- 

 gion, spots pos- 

 teriorly. 



Dorsum black 



22-29 I 6-9 



26-29 I 5-10 

 (Or indistinct.) 

 41 



33-68 



34-63 



-20 



10-18 



'18-19 



18-20 

 16-19 

 20-22 

 16-22 

 18-20 

 20-22 



18 



17 



17-19 



18 

 17-21 



18-22 



16-17 



14-18 

 14-17 



18 

 14-17 

 16-18 



18 



16 

 16-17 

 16-17 



15 

 16-17 



16-18 



8-10 



9-10 

 7-11 

 9-11 

 9-11 

 10 

 fr-12 



10 

 9-12 

 9-10 



9-11 

 9-11 



10-14 



8-14 

 7-14 

 8-14 

 7-13 

 12-14 

 15 



8-10 



6-8 



7-10 



9-13 

 11-14 



Slightly longer than 

 broad. 



As broad as long 



do- — - 



do— — - 



do- -- 



do 



do 



Twice as long as broad. 



do - 



do. .- 



.do. 



Almost twice as long as 



broad. 

 As broad as long 



146 



176 



256 



25 



190 



5 

 30 

 22 



2 



255 



38 



1,157 



attainment of a valid understanding of intergeneric relationships. 

 The number of genera of Colubridae that have been studied in- 

 tensively is too small to warrant the drawing of any conclusions 

 concerning aflSnities between genera of that family, 



KEY TO THE FORMS OF THE GENUS PITUOPHIS 



a'. Eye in contact with 2 supralabials; only 2 prefrontals present normally. 



¥. Dorsum lacking continuous stripes, but with a series of ovoid, quadrangular, 



or saddle-shaped spots throughout; ventrals 211-235. 



c^ Dorsal spots on body and tail more than 40; interspaces between spots 



generally each less than 4 scales in length; posterior spots quadrangular 



without a tendency to fuse at the sides (throughout Mexico to CaU- 



fornia and Texas) deppei deppei (p, 25) 



c'. Dorsal spots on body and tail less than 40; interspaces between spots 

 generally each 5 or more scales in length; posterior spots saddle-shaped 

 and tending to fuse at the sides (Miquihuana and Buenavista, Mexico) 



deppei jani (p. 42) 



&*. Anterior part of dorsum with 2 continuous black vertebral stripes, central 



portion of body with 2 rows of ovoid annuli, and posterior dorsum with a 



single row of spots; ventrals 236-249 (Guatemala to Guerrero, Mexico) 



lineaticollis (p. 47) 



o*. Eye in contact with one or no supralabials; 4 prefrontals present normally. 



6*. Rostral at least twice as long as broad; dorsum black and white with less 



than 40 spots, or brown and white with anterior spots indistinct, or 



uniformly black; rarely more than 1 preocular; azygos never present 



between frontal and prefrontals. 



