80 BULLETIN 61, UNITED STATES NATIONAL MUSEUM. 



souri, bencling southward in Illinois to include most of that State 

 above the latitude of St. Louis. Above this latitude in Missouri and 

 southern Iowa, however, the extensive meadows and open character 

 of the woods relate this region to the prairie proper, and it is doubt- 

 less for this reason that we find radix extending southward to St. 

 Louis, Missouri, and, although its southern boundary is not definitely 

 known, it probably approximately coincides with the border of the 

 southeastern deciduous forest that lies a little to the south of these 

 localities, curving around the northern boundary of the Ozarks to 

 the 98th meridian. 



Illinois north of the 39th parallel is true prairie, and radix is known 

 to occur throughout the State above St. Clair and Wabash counties, 

 but in western Indiana, which is not a prairie State, the prairie comes 

 in contact with the forest and breaks up into grassy peninsulas and 

 islands that might be expected to introduce radix well beyond the 

 prairie proper. Nevertheless, the most eastern localities for which we 

 have authentic records are Chicago and Mount Carmel, Illinois. In 

 1881 Hay (1881, 738) recorded a specimen of radix in Butler Univer- 

 sity. He says of this specimen that "it is a good and well-character- 

 ized specimen of Eutxnia radix, that I have every reason to believe 

 was found at Irvington, near Indianapolis. The species is found at 

 Bloomfield, Illinois, and is included by Dr. W. H. Smith, in his Cata- 

 logue of the Reptiles and Amphibians of Michigan, as occurring in 

 that State." In 1887 (1887, 65) he includes it in his list of Indiana 

 Reptiles and Amphibians. Doctor Cope (1888, 400-401) described 

 as a new variety {melanotxnia) two specimens of radix presumably 

 from Brookville, Indiana, and we have examined two specimens from 

 Purdue University, belonging to the Butler collection, and presum- 

 ably also from Brookville. Unfortunately, however, doubt attaclies 

 to the locality of all of these specimens. Hay did not seem ab^- 

 lutely sure that the Butler University specimen came from Irvirig;- 

 ton, and in the case of the Purdue specimens no locality is given, 

 while a third is labeled "Illinois; collector, A. W. Butler." I 

 believe, therefore, that while it is very probable that radix will be 

 found in western Indiana, particularly in meadows and clearings, 

 the present records can not be accepted as evidence of its occurrence 

 in the State. 



In general, then, the range of radix may be defined as the plains 

 and prairie regions of central North America. Owing to its prefer- 

 ence for wet, marshy habitats it is more generally distributed in the 

 prairie region and pushes slightly to the eastward beyond this feature 

 in the encircling brush prairie zone, but is limited by the margin of 

 the forest of eastern North America, while to tlie westward it enters 

 and extends entirely across the plains region, possibly by adhering, in 

 a general way at least, to the valleys of the large streams, which also 

 support a well-defined flora of the prairie type (fig. 25). 



