Pituophis sayi sayi (Schlegel) Common Bull Snake 

 Dorsal blotches incurved before and behind; Colo, to Cal. southwards 

 Pituophis sayi affinis Hallowell Arizona Bull Snake 



63. Anterior mid-dorsal spots often incurved before and behind; central 



mid-dorsal spots reddish, posterior ones black; S. Cal. 



Pituophis vertehrahs (Blainville) Southern California Gopher 

 Snake 

 Mid-dorsal spots oval or squarish and similarly colored 64. 



64. Anterior mid-dorsal spots usually joining lateral spots and often joining 



each other; S. Cal. 



Pituophis catenifer annectens (B. & G.) Checkered Gopher 

 Snake 

 Anterior mid-dorsal spots scarcely joining lateral spots and never joining 

 each other 65. 



65. Light-colored scales on anterior part of body usually each with a central 



dark dot; Colo, to Wash, and Cal. 



Pituophis catenifer deserticola Stejneger Desert Gopher Snake 

 Light-colored scales not dark dotted; Wash, to Cal. 



Pituophis catenifer catenifer (Blainville) Pacific Gopher Snake 



66. With one internasal plate; uniform dark brownish color above; belly yel' 



lowish or pinkish; Va. to Fla. and Texas 



Haldea striatula (Linn.) Brown or Ground Snake 

 (Potamophis striatulus (Linn.) ) 

 With two internasals; usually with three lengthwise stripes or with sev 

 eral rows of spots; belly spotted or plain 67. 



67. Nostril surrounded by a single plate (nasal) which is vertically grooved 



below the nostril; back usually striped; with two rows of dark spots 

 close together along the middle of the belly; most of the central states 

 to Texas 



Tropidoclonion hneatum (Hallowell) Striped Swamp Snake 

 Nostril between two nasal plates; back striped or spotted; belly spots, if 

 present, in two widely separated rows Garter Snakes 68. 



68. With a pale stripe lengthwise along each side passing anteriorly through 



the third and fourth (and sometimes the second) rows of scales up 



from the ventral plates 69. 



With a pale stripe passing anteriorly below the fourth row of scales 



(usually through the second and third) or sometimes absent 74. 



69. Lateral stripe anteriorly on the third row of scales and one-half the sec 



ond and fourth rows; upper labials six or seven; Ind. to N. Y. and 

 Wis. 



Thamnophis hutleri (Cope) Butler's Garter Snake 

 (Eutaenia hutleri Cope) 

 Lateral stripe anteriorly on the third and fourth rows of scales; upper 

 labials on each side seven, eight or nine 70. 



70. Tail about one-fourth or less total length; scales along the edge of the 



upper lip usually margined with dark or with dark coloring; belly 

 often with dark markings 7L 



400 



