﻿Dec, 1895.] 



SOREX HOYI. 



89 



teeth of certain species, with a page of explanation facing each plate. 

 (Monog. Insectivora, Part III, fasc. 1, May, 1890). The present species 

 is named and its peculiar dentition shown in PI. XXIII, fig. 6, of this 

 work. But the remarkable shape of the palate and pecuharities of the 

 skull as a whole are not shown. The skull was removed from the alco- 

 holic specimen by Dr. Dobson, and I have sometimes wondered whether 

 by any possible accident it could have been transposed with that of 

 some Asiatic species, it is so very unlike all known American Shrews. 

 When the specimen was returned the alcoholic bore my original label 

 and number (1001), but the skull was numbered differently (1886; its 

 proper number is 4861). Dr. Dobson afterwards wrote me that his num- 

 ber was an error, and that the skull belonged to my alcoholic Xo. 1001. 



Subgenus MICROSOREX Baird, 1877, 



Microsorex B&irrJi, in Coues Precursory Notes on American Insectivorous Mammals, 

 Bull. U. S. Geol. and Geog. Surv., Ill, 646, May 15, 1877. Type, Sorex hoyi Baird. 



QeograpMc distribution. — Boreal zone from northern Xew England 

 and the Maritime Provinces of Canada (on both sides of the St. Law- 

 rence) westward to British Columbia. Not known to range southward 

 on any of the mountain systems. 



Diagnosis. — Teeth 32, as in Sorex^ but third unicuspid minute, trans- 

 versely elongated, and wedged in between second and fourth so as to 

 be hardly visible (and often not visible) from outer side (see PL IX, 

 figs. 5a, 5c). The ridge on inner side of first and second unicuspids 

 tends to develop a small accessory cusp at base, just above the 

 cingulum.^ Brain case narrow, depressed, and much elongated 

 (PI. XII, figs. 4, 5). Mandible relatively short and heavy (PI. IX, 

 fig. 5/;). The mandible, compared witli that of Soreoo jyersonatus, is 

 shorter and heavier, with the coronoid process upturned more nearly 

 at right angles to the ramus. The anterior lower incisor reaches poste- 

 riorly completely under the first and second and partly under the third 

 lateral tooth. 



The subgenus is represented, so far as known, by a single species of 

 very small size. 



SOREX (MICROSOREX) HOYI Baird. 



(PI. IX, figs. 5-5c; PL XII, figs. 4,5.) 



Sorex hoyi Baird, Mammals N. Am., 32-33, PI. XXVIII, 1857. (From Racine, Wis.) 

 Sorex thompsoni Baird, Mammals N. Am., 34-35, PL XXVII. (From Burlington, Vt.) 



Type locality. — Eacine, Wisconsin. 



a eneral characters. — Size small (hind foot 10.5 mm.) ; tail considera- 

 bly shorter than body without head; third unicuspidate tooth minute, 

 scarcely visible between second and fourth. 



iTMs cusplet may be seen also in Sorex peirsonatns, though commonly less devel- 

 oped. It is figured by Miller on page 42 of this number of X. Am. Fauna (fig. Ic). 



