1915.] 



INTRODUCTION. 



17 



may be simple, spined, or notched; in Scapanus, simple, but usually 

 notched; in Condylura usually simple, but sometimes spined; and in 

 Parascalops and Neiirotrichus, almost invariably simple. There is a 

 marked tendency in Scalopus and Scapanus toward abnormal denti- 

 tion; this appears not only in the production of accessory cusplike 

 processes on the cingula of the premolars, but also in the increase or 

 reduction of the number of premolars ordinarily present. The 

 tendency in Scalopus is toward extra premolars; in Scapanus -it is 

 toward the suppression of premolars, though in each of at least seven 

 skulls examined there is a supernumerary premolar. 



The general color of specimens from a given locality is constant, 

 except for seasonal variations. Individual abnormalities, however, 

 occur frequently in Scalopus and Scapanus. The common type of 

 chromatic variation in Scalopus is the occurrence of white, cream, 

 orange, or ochraceous spots or blotches, appearing usually either on 

 the face or on the ventral parts. Scheffer ^ has remarked upon the 

 prevalence of this form of variation in Scalopus at Manhattan, Kans., 

 where he finds that certain regions of the body of a large majority 

 of the moles taken are washed with a tinge of orange, or that on the 

 head or abdomen are distinct patches of this color. Variations simi- 

 lar to these, however, crop out in many localities. They are not 

 confined to any particular species or subspecies, but appear most 

 frequently in iS'. a. machrinus and S. a.maclirinoides. In many specimens 

 this form of variation is, apparently, partial albinism, the patches 

 being nearly white and the slight creamy or brown tinge probably 

 being due to glandular or other stains. Blotches in other specimens 

 range from cream color to shades of buff, orange, and bro^vIl, and show 

 clearly that they are due to mutations of color. A unique variation 

 occurs in a specimen from Warsaw, 111. (No. 5429, American Museum 

 of Natural History). The entire underparts of this animal, except 

 the vent and right hind foot, are a beautiful capucine buff, as are 

 also the nose and right side of the face; a narrow band of this color 

 extends for a short distance up the posterior part of each flank, and 

 anteriorly another band passes over the shoulders and across the nape, 

 forming a complete collar; the remaining dorsal parts are much as in 

 normal specimens, but perhaps slightly more vinaceous. Another 

 peculiar variation occurs in a specimen from Madison, Ind. (No. 

 112008, United States National Museum). The entire dorsal parts 

 of this individual are normally colored; the ventral parts are pale 

 ochraceous-salmon to ochraceous-buff, irregularly spotted and 

 blotched especially laterally with grayish fuscous, the whole effect 

 reminding one in certain respects of the ventral parts of some of the 

 spotted tiger-cats or ocelots. 



1 Schefler, T. H., Kansas State Agr. College Exp. Sta. Bui. 168, p. 4, 1910. 



