10 RE VISION OF A ME RICA X MO L ES— TB UE. 



The most northern division of Dr. Allen's warm temperate subregion 

 is separated under the name of the Alleghauian fauna. This includes 

 the greater part of the northern tier of States (east of tlie one hun- 

 dredth meridian), lower Canada, northeastern Ohio, the greater part of 

 New York and Pennsylvania, and of the New England States (except 

 the most elevated portions), and the Alleghanies. In Dr. Allen's sys- 

 tem, therefore, this region is a part of the larger southern one. 



Dr. Merriam looks upon this area as a neutral zone, connecting the 

 northern and southern, but possessing no individuality of its own. 

 He styles it the " transition zone." It is with this area that we are 

 most concerned. 



Upon examination of the mai)S which follow (pp. 28, 55, 74, 89, 103), 

 it will be found that the boundaries of the areas of the several east- 

 ern genera coincide in some part with those of the faunal areas just 

 mentioned. 



Thus, the area of Scalops is almost exactly coextensive with and 

 coincident with the humid province of the warm temperate subregion 

 as marked out by Dr. Allen. But it goes a little farther west toward the 

 one hundredth meridian and a little farther south to the Rio Grande 

 (and perhaps a short distance south of it). Also, there is no certain evi- 

 dence that Scalops reaches North Dakota and Manitoba. Except in 

 these details the genus is strictly representative of the humid province. 



There is, however, a certain peculiarity of the distribution of the 

 genus that requires mention. It unquestionably occurs in the Alle- 

 ghany Mountains — that is, in the southern extension of the cold tem- 

 perate or boreal area. 



In this particular, at least, following Dr. Allen's ideas, its distribu- 

 tion is not controlled by temperature, and we shall need to ask the 

 question. Why does not this mole range farther north ? 



If we revert here to Dr. Merriam's system, we escape this difficulty, 

 because the Alleghanies in his latest map are represented as belonging 

 entirely to the "transition" zone, which is neutral and in which we 

 may expect to find southern as well as northern forms. 



The range of the genus Condylura, as will appear from examination 

 of the map, is less in harmony with Allen's faunal areas. Tlius, it 

 extends to Hudson Bay on the north, to Indiana, Ohio, and the Alle- 

 ghanies on the south, and also leaves the mountains and extends some- 

 what over the lower lands, to the east of them. 



The genus, therefore, occupies at once parts of both the cold temper- 

 ate and warm temperate regions, and, so far as one genus goes, tends 

 to negative the distinctions made between these faunal regions, or at 

 least to indicate that the "Alleghauian fauna" is not part of the warm 

 temperate subregion. The matter assumes a more satisfactory aspect 

 when viewed in connection with Dr. Merriam's scheme. In the termi- 

 nology of his system, Condylura occupies a portion of the boreal region 

 and of the transition zone, and a number of isolated fragments or 

 islands of the latter to the south and east of the main area. Viewed 



