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BULLETIN 61, UNITED STATES NATIONAL MUSEUM. 



opened furrows in the plowed fields seizing the earthworms that are 

 turned out by the plows. In the stomachs of specimens from a patch 

 of upland prairie in Clay County, Iowa, I found two small mammals 

 and a bird. All of these had undoubtedly been found dead, as 

 they were all badly flyblown. This indicates that radix, like other 

 members of the genus (see notes on sirtalis and elegans), will occa- 

 sionally eat dead animals. However, even in the upland habi- 

 tats, the principal food of radix in the prairie region is the leopard 

 frog. Where there is long grass this frog may, in western Iowa, be 

 found quite commonly a mile or more from water. In view of the 

 intense heat and drouth, of the hot summer days it seems rather 



Fig. 21.— Habitat of Thamnophis radix and T. sirtalis parietalis. morainic hills in Clay 

 County, Iowa. t. radix is frequently found on these grassy ridges, a mile or more from 

 water. T. sirtalis parietalis is also Found in this habitat, but only rarely. 



remarkable that the frog can live in these habitats. Its ability to 

 do so is apparently due to the fact that the dense growth of grass is 

 wet with dew for the greater part of each day, for where it is grazed 

 closely frogs are very scarce. 



Coues states that they are preyed upon by hawks. I have seen 

 this several times, but an even greater enemy is the American bittern, 

 which nests in great abundance about the margins of the sloughs. 

 These birds feed voraciously on both frogs and snakes. 



Very little is known of the breeding habits of radix. Coues and 

 Yarrow (1878, 278) state that "the greater part of the females ob- 

 served in July and August will be found pregnant, the young number- 



