54 



INSKCTIVORA 



times almost whitish, the line of demarcation along sides usually 

 evident though not very conspicuous. Feet pale wood-brown 

 with a silvery gloss or suffused with drab, sometimes noticeably 

 lighter than back. Tail concolor with back above, not so dai'k 

 below. 



SJcuU. — Apart from its conspicuously smaller size (condylo- 

 basal length, 14 -8 to 16 mm. instead of 17 '8 

 to 20 mm.) the skull differs notably from 

 that of Sorex arancus and S. alpinus in the 

 narrower, more elongate brain-case, the outline 

 of which when viewed from above is distinctl}^ 

 oval instead of sub-circular. Antero-external 

 portion of border flattened, though less notice- 

 ably than in Sorex araneus. Owing to its 

 different form the brain-case is less abruptly 

 marked ofl' from interorbital region than in 

 Sorex minutus. ^^^® other European species. Depth of brain-case 

 Nat. size. usually less relatively to breadth than in 



S. araneus. Lachiymal foramen opening over 

 posterior half of first molar. 



Teeth. — Aside from their very much smaller size (upper 

 tooth-row 6 to 7 mm. instead of 8 to 9 • 6 mm.) the teeth of 

 Sorex minutus differ in numerous details of form from those of 

 S. araneus. Anterior upper incisor with basal lobe nearly as 

 high as anterior cusp, so that the two points of the tooth are 

 essentially in line with the tips of the first three unicuspids. 

 When viewed from below the posterior lobe appears, however, 

 distinctly smaller than anterior cusp, while from the side its 

 outline is conspicuously higher and narrower than that of first 

 unicuspid. Anterior lower incisor with 

 first lobe on cutting edge as well defined 

 from anterior point of tooth as from second 

 lobe, and lengths of bases of all three lobes 

 approximately equal. Upper unicuspids not 

 essentially different in form from those of 

 Sorex araneus, but crowns perceptibly longer 

 than wide and less abruptly rounded off 

 anteriorly, the resulting form less nearly ^'*^' ^^' 



„ T 1 i 1 • J.1 J.T • -i" Sorex minutus. Anterior 



square. In lateral view the outline is quite teeth in profile, x 5. 

 as in the larger animal. The relative size 



of the unicuspids differs markedly from that in the larger 

 animal. The first, second and third are sub-equal, with the 

 second usually a trifle smaller than the third, and the first with 

 distinctly the greatest crown area. Fourth slightly smaller than 

 third, and fifth equally smaller than fourth'"', between which and 

 large premolar it is tightly crowded. First lower unicuspid 

 diflering from that of S. araneus in its greater length along 

 cingulum and less height of cusp, its form when viewed from 

 * Sometimes equal to fourth or slightly larger. 



