COLUBRID^E. CX. 193 



545. B. radix Baird & Girard. Green or black with three 

 narrow yellow stripes ; six series of black spots ; scales very rough, 

 the outer row broad ; colors deep ; head short ; tail short, 5 in 

 length; scales 19 to 21 ; V. P. 150 to 160. L. 25. Wis. to Ore- 

 gon. (Lat., root, from Root R., Wis.) 



aa. Lateral stripe on 2d and 3d rows of scales ; body stoutish, the tail 4 in 



length. 

 d. Scales in 19 rows. 



546. E. sirtalis (L.). COMMON GARTER SNAKE. STRIPED 

 SNAKE. Olivaceous, dorsal stripe narrow, obscure ; 3 series of 

 small dark spots on each side, about seventy between head and 

 vent ; sides and belly greenish ; lateral stripes rather broad but 

 not conspicuous ; colors generally duller than in the other species. 

 V. P. 130 to 160. N. Am., everywhere except in Cal. ; our com- 

 monest snake ; very variable. (Lat., like a garter.) 



Prominent varieties are : Var. ordinata (L.) with the stripes ob- 

 scure or wanting and the spots more distinct, square, 85 in num- 

 ber before anus ; V. P. spotted on sides. Chiefly northeastward. 

 Var. dorsalis (Baird & Girard) has the dorsal stripe broad, and two 

 rows of small distinct spots on each side. N. Am., everywhere. 

 Var. obscura Cope, uniform brown, the spots obscure, the bands 

 distinct. Var. parietalis (Say) has the stripes dull greenish and 

 the space between the lateral spots of a more or less vivid brick 

 red. Ind. to Cal. 



dd. Scales in 21 rows. 



547. E. vagrans Baird & Girard. Ashy brown, usually a 

 narrow dorsal stripe; each side with about 100 small black spots 

 in two series. V. P. 160 to 180. Ills. (Nelson) to Cal. 



277. REGINA Baird & Girard. 

 a. Postorbitals 2. 



548. R. rigida (Say). Greenish brown ; two brown dorsal bands ; 

 a brown spot at base of each scale on sides ; belly yellowish, blotched; 

 outer row of scales smooth; scales, 19 ; V. P. 130 to 170. L. 24. 

 Penn. to Ga., chiefly E. of mts., W. to Central 111. (Hay.) 



549. R. leberis (L.). Chestnut brown; a yellow lateral band 

 and three narrow black dorsal stripes ; belly yellow, with two brown 

 bands; scales all keeled; scales 19; V. P. 140 to 150. L. 24. 

 U. S., about streams. (Lat., cast-off snake-skin.) 



aa. Postorbitals 3, the lower very small. 



550. R. grahami (Baird & Girard). Brown; a pale brown 

 dorsal band; besides this two narrow black streaks on each side ; a 

 straw-color lateral stripe ; belly unspotted ; scales all strongly 

 keeled; head slender; scales 19 to 21; V. P. 160. L. 20. Mis- 

 sissippi Valley, N. to Mich. 



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