278 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



are indications of obscure dark spots, scarcely or not, however, traceable 

 in definite rows. In all the specimens, the series of spots below the lat- 

 eral line are well marked and distinguishable, and in many cases the 

 line of spots just above the lateral line is fairly perceptible. The belly 

 is pale glaucous-olivaceous, touched with blackish on the sides of the 

 scutes, and sometimes this color mingles with the dark of the sides below 

 the lateral stripe. Unlike those species in which the lateral band is 

 lower down, there is not so much difference in the size or shape of the 

 first and second dorsal rows. The superior labials are normally seven, 

 sometimes eight ou one or both sides; they are light-colored, like the 

 belly, but each has a touch of blackish along the posterior border. The 

 dorsal rows are normally 21, and all quite broad. All the dorsal scales are 

 strongly carinated, giving the animal a roughened, scabrous appear- 

 ance. The length is oftener 2 to 2^ feet than more, but at all ages the 

 bulk of the snake, as already indicated, is considerable. 



The specimen here described, a gravid female, and others of the nu- 

 merous ones collected, agree perfectly with the original diagnosis of the 

 type from Eacine, Wis. (whence the name "radix" is derived), and 

 equally well with Mr. Kennicott's subsequent description of a specimen 

 from Fort Snelling, Minn. Throughout the Red Eiver region, from 

 Pembina to where the Ooteau de Missouri crosses the line, it is the 

 characteristic Ophidian, the principal and almost the only representative" 

 of its order, outnumbering all the others put together. Indistinguisha- 

 ble specimens also occur in the eastern portions of the Missouri region 

 at the same latitude, though there the greater number are of the 

 twiningi type, which farther westward prevails altogether. 



In the more fertile portions of the Eed Eiver Valley itself, this snake 

 may be found almost anywhere in the brush and herbage. Out on the 

 dryer prairie beyond, it is chiefly confined to the pools and streams, or 

 their immediate vicinity. Numbers are found basking together on the 

 muddy borders of the sloughs, or among masses of aquatic vegetation, 

 where they find ample subsistence during the summer months in the 

 tadpoles, young frogs, and various water insects. They are themselves 

 preyed upon by hawks, especially the Marsh Harrier {Circus cyaneus 

 liudsonius) and Swainson's Buzzard {Buteo swainsoni). They are less 

 active than some of the slenderer species, are readily caught, and when 

 captured make little or no resistance. Only the largest individuals 

 assume for the moment a defensive attitude and attempt to bite ; most 

 may be at once handled with impunity. The greater part of the females 

 observed in July and August will be found pregnant, the young num- 

 bering sometimes as many as thirty or forty. Individuals were taken 

 in coitu in September and part of October. These observations together 

 indicate a period of gestation protracted for the greater part of a year. 

 The snakes become much less numerous in the latter part of September, 

 but Dr. Ooues occasionally saw them abroad ou warm days up to the 

 middle of October, even after there had been snow, sleet, and freezing of 

 the more shallow waters. 



