﻿66 



NORTH AMERICAN FAUNA. 



[Xo. 10. 



with grayisli asli; tail bicolor: dusky above, tiesh color below; feet 

 flesli color. Brown pelage: Everywhere dull chestnut brown, paler 

 below; tail and feet as in other pelage. 



Cranial and doit a J characters. — Skull similar to that of 8. richardsonij 

 but averaging slightly sraaller; rostrum and brain case lower; con- 

 striction flatter and broader; interpterygoid notch slightly broader; 

 anterior opening of infraorbital canal large and covering nearly whole 

 of m^ ; opening of lachrymal canal over interspace between m^ and 

 (instead of over middle of m\ as in ricliardsoni). Molariform teeth 

 much more deeply excavated; unicuspids A^ery much smaller and less 

 swollen, but with a well developed vertical ridge on inner side. 



Measurements. — Average of 6 specimens from Peterboro, X. Y. (type 

 locality): Total length, 116 mm.; tail vertebrc^e, 15.4 mm.; hind foot, 

 13.2 mm. Average of 1 specimens from Eenovo, Pa.: Total length, 

 108.5 mm.; tail vertebriB, 13.5 mm.; hind foot, 12.3 mm. Average of 3 

 specimens from Lake George, N. Y. : Total length, 118.7 mm. ; tail 

 vertebra^, 17 mm. ; hind foot, 13 mm. 



General remarl^s. — Sorex fumeus is the larger and more boreal of the 

 two species of Sorex inhabiting the northeastern United States and the 

 higher Alleghenies farther south. It does not require close com]3arison 

 with any other species. Specimens from the Adirondacks, the moun- 

 tains of Xew England, and Eoan Mountain, Xorth Carolina, are larger 

 and have higher brain cases than the typical form from central Xew 

 York (Peterboro) and Pennsj^lvania (Eenovo). The two pelages in this 

 species are very different and are clearly seasonal — the plumbeous is 

 the winter coat, the brown the summer. This is well shown in a series 

 of 18 specimens from Eoan Mountain, on the boundarj- between ISTorth 

 Carolina and Tennessee. Eight of these are in the plumbeous pelage, 

 and were collected from October 11 to May 3 ; and ten are in the chest- 

 nut-brown pelage, and were collected from June 2 to September 11. 



Sorex fumeus of the northeastern States resembles S. trowhridgii of 

 the Pacific coast of Oregon and Washington in many resx^ects. In 

 color both are plumbeous or dark slate, in which particular they differ 

 from all other members of the genus inhabiting the United States. 

 Their skulls and teeth also are very much alike, though S. troichridgii 

 has the small third unicuspid characteristic of most west American 

 Shrews. The skull of fumeus is somewhat the larger, but the tooth 

 rows are of approximately the same length. The molars are essentially 

 the same in both, but the i)remolar and. unicuspids are materially larger 

 in fumeus — the premolar larger in every way and the unicusi^ids broader. 

 The last upper molar, on the other hand, is largest in troivhridgii. In 

 fumeus the large i^remolar is much more deeply excavated posteriorly. 



Specimens examined. — ^Total number, 27, from the following localities : 



New York: Peterboro (type locality), 1; Lake George, 3. 



New Hampsliire : Ossipee, 1. 



Penusylvauia : Renovo, 4. 



North Carolina : Eoan Mouutaiu, 18. 



