338 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1923 



especially along the upper Potomac above the city. Adult speci- 

 mens are commonly from 24 to 30 inches long. In color, the copper- 

 head is hazel brown, with a series of hourglass-shaped darker 

 blotches along the back. Equally venomous is the mocassin, or 

 cotton mouth, but he is an aquatic species and does not range so 

 far to the north as does th# copperhead. 



The common water snake (Natrix sipedon) and the southern 

 water snake (N. taxispilotus) are often mistaken for the moccasin; 

 they are ill-tempered snakes but harmless, and on close examination 

 may be distinguished from the moccasin and copperhead by the 

 absence of the deep " pit " between the eye and nostril, a charac- 

 teristic feature of those venomous species and the rattlesnakes. 



Other harmless American snakes kept in the collection are the 

 black snake {Coluber constrictor) sometimes called the " blue racer," 

 and his near relative, the coach whip snake (C. flagellum) , both of 

 which sometimes attain a length of 5 feet. Several species of the 

 pretty little garter snakes, as well as the king snake, the pine snake, 

 chicken snake, bull snake, gopher snake, and others are commonly 

 shown. 



