■'ml^] ALLEN — MAMMALS 53 



General characters. — A large brown shrew, with a decided yellowish 

 wash over the ventral surface of the body and throat. Tail distinctly 

 bicolor, and relatively short (about half the length of head and body). 

 Skull long, with oval brain-case; the four first unicuspid teeth of the upper 

 jaw resembling those of the American shrews in that they are in two pairs, 

 the two anterior teeth larger and subequal, the two posterior much smaller 

 and likewise of approximately the same size. 



Description. — The type in winter pelage has the entire dorsal surfaces 

 of the head, body, and tail, 'Front's brown' (of Ridgway, 1912), the feet 

 paler. The individual hairs are nearly 7.5 mm. long on the back, of which 

 the basal 5 mm. are slaty; a narrow ring of 'pale buff' follows, then the 

 brown tip. The pale buff ring gives a slight yellowish cast to the otherwise 

 uniformly brown pelage. At the sides of the head and body the brown 

 tips disappear gradually, so that this region is pale buff, but not in strong 

 contrast to the back. Ears prominent, well haired, in color like the back. 

 Ventral surfaces of the throat and body dull white, with a wash of the same 

 'pale buff' which gives a soiled yellowish effect to this region. The lower 

 side of the forearms is clearer white, in distinct contrast to the rest of the 

 ventral surface. Tail clothed with short stiff hairs, 'Front's brown' above, 

 clear silvery white below, with a distinct line of demarcation and marked 

 terminal pencil of brown hairs. 



A specimen taken October 19, 1911, seems to be still in summer pelage. 

 It is similar to the type, except that the brown area of the back is rather 

 more sharply defined at the sides. 



Skull and teeth. — The skull is long, with the dental portion shorter as 

 compared with S. araneus. The interorbital region is broad, and its out- 

 line merges gradually into that of the oval brain-case, with only a slight 

 angular development postorbitally. Sides of the brain-case slightly rough- 

 ened for muscle attachment. Lachrymal foramen directly over the middle 

 of the first molar. Interpterygoid fossa distinctly contracted posteriorly. 

 Viewed from below, the postero-internal lobes of the first incisors are so 

 slightly developed that they are farther from the mid-Une of the palate 

 than are the first unicuspids. The crown areas of the unicuspids form a 

 regularly decreasing series; in outline the four first are rectangular, dis- 

 tinctly broader than long, and the fifth is triangular, with its base internal. 

 The pigmentation of the cusps is normal; the tip of the small fifth unicuspid 

 is pigmented, as are also the protocones of all the molariform teeth. In 

 occasional specimens, however, the fifth unicuspid may be so small or so 

 worn that it shows no pigment; in none of the many specimens examined 

 does the pigment extend to the hypocones. In side view the four anterior 

 unicuspids are distinctly in pairs, the anterior two larger and subequal, the 

 posterior two much smaller and likewise subequal. The fifth is very small 

 and distinctly internal to the tooth-row, though fully visible in lateral 

 view. The first lobe of the anterior lower incisor is nearly obsolete; the 



