COLUBRID^E. CX. 197 



a yellowish one ; the lines of each pair separate on sides and be- 

 come confluent with the nearest one of adjacent pair; head red. 

 Scales 21. V. P. 180 to 210. L. 30 to 50. Md. to Kan. and S. ; 

 exceedingly variable, running by degrees into the following varie- 

 ties, extremes of which bear little resemblance to the typical 

 doliatus. (Lat., sorrowful.) 



Var. coccineus Schlegel, the black rings not confluent and usually 

 meeting on belly. S. 111. to Fla. and W. 



Var. triangulus (Boie). MILK SNAKE. HOUSE SNAKE. SPOT- 

 TED ADDER. Grayish, with three series of brown, rounded 

 blotches bordered with black, about fifty of them in the dorsal 

 row ; an arrow-shaped occipital spot ; belly with square black 

 blotches. Va. to Iowa, and N. ; very common. 

 aa. Dorsal scales in 25 rows. 



571. O. rhombomaculatus (Holbrook). Light chestnut, back 

 and sides with 3 series of darker rhomboidal blotches, about 50 in 

 dorsal series ; belly obscurely blotched. V. P. 200 to 205. 111. to 

 N. C. and S. 



572. O. calligaster (Say). Light olive gray, with about sixty 

 quadrate, chestnut colored, emarginate blotches on back and two 

 rows of smaller ones on each side. 111. to Kansas and S. (*aX6s, 

 beautiful ; yaarrjp, belly.) 



286. OSCBOLA Baird & Girard. (Name of an Indian chief.) 



573. O. elapsoidea (Holbrook). SCARLET SNAKE. Brilliant 

 red, with about 18 pairs of jet black rings on body and three on 

 tail, each pair enclosing a white ring; the black rings tapering to- 

 wards the sides, the white ones spreading ; a yellow collar on upper 

 part of neck, bordered by black lines ; rostral plate very broad ; 

 resembles closely 0. doliatus. Scales 19. V. P, 175 to 180. L. 20. 

 Va. to S. 111. and S. 



287. CEMOPHORA Cope, (typos, muzzle ; <popos, bearing.) 



574. C. coccinea (Blumenbach). Crimson, with 20 to 26 black 

 rings enclosing yellow ones; yellowish below. V. P. 160 to 170. 

 S., N. to Ark. (Lat., crimson.) 



288. HETERODON Beauvais. (eWpoy, different; od<bv t tooth.) 

 a. Vertical plate in direct contact with frontals. 



575. H. platyrhinus Latreille SPREADING ADDER. BLOW- 

 ING VIPER. Brownish or reddish, with about 28 dark dorsal 

 blotches, besides lateral ones and half rings on the tail ; often (var. 

 niger) uniform black. Vertical plate longer than broad, about 

 equal to occipitals. L. 30. V. P. 120 to 150. Scales 23 or 25. 

 E. U. S., abundant. A very variable species; when angry it de- 



