Genl. Char. Larger and darker than S. personatus; tail about 

 equal to body. 



Color. Above sepia brown and dusky; posterior part of back 

 darkest; beneath ash gray; tail above dusky, beneath whitish. 



Measurements. Total length, 105-108. i ; tail vejtebras, 45.5-46.9: 

 hind foot, 12. 7-1 3. 4. 



b.—arcticios. {Si>rex), Merr. , Proc. Wash. Acad. Scien., 1900, p. 17. 



Type locality. St. Michael's, Alaska. 



Genl. Char. Similar to 5. personatus; tail longer, color paler. 



Color. Summer Pelage. Above pale drab brown; beneath ashy 

 white. 



Winter Pelage. Above dusky brown and white; beneath silverj' 

 white washed with very pale buff. 



Measurements. Total length, 108; tail vertebrae, 39; hind foot, 12. 



538. richardsoni. (Sorcx), Bach. Journ. Acad. Nat. Scien. Phil., vol. 



vii, 1837, p. 383, pi. xxlv, fig. 5. 



parvus. Rich, (nee Say), Faun. Bor. Am., 1829, p. 8. 



Type locality. Unknown. 



Geogr. Distr. Northern Minnesota and Saskatchewan Plains. 



Genl. Char. Size large; tail short. Skull similar to that of 5. 

 futneiis, but generally larger. 



Color. Above seal brown; sides ochraceous; beneath plumbeous 

 tinged with chestnut; tail above dusky, beneath brownish. Some 

 specimens have ashy sides, and under parts ash gray. 



Measurements. Total length, about 113; tail vertebrae, 40; hind 

 foot, 14. 



539. tundrensis. {Sorex). Merr., Proc. Wash. Acad. Scien., 1900, 



p. 16. 



Type locality. St. Michael's, Alaska. 



Genl. Char. Size large; pelage bicolor in winter, tricolor in 

 summer. 



Color. Summer Pelage. Top of head and back drab brown; sides 

 paler buffy brown; under parts whitish. Tail above brown, tip dusky, 

 beneath buffy. 



Measurements. Total length, loS; tail vertebra?, 32; hind foot, 13. 



540. sphagnicola. {Sore.x), Coues, Bull. U. S. Geol. and Geog. 



Surv., vol. iii, 1887, p. 650. 

 belli, Dobson, Ms. Merr. Proc. Biol. Soc. Wash., 1892, p. 25. 

 Type locality. Vicinity of Fort Laird, British Columbia, lat. 60°. 

 Geogr. Distr. British Columbia and Hudson Bay. 

 Genl. Char. Size medium; tail shorter than body; large, com- 



