92 MICR0TU9. 



Microtus scirpensis liailcv. Hioloolcal Survov collortion. 



North Amer. Fauna, X.>. 17, i>\>- !•''>, ■>^--V-\ .Iiiiicd, U)00. 

 fsail- Skin and skull. Adult female. Aniarg'O.sa River, InyoCounty, 

 California. Fel)ruarv 26, 1SJ>1. Collected hy V. Bailey. Oricri- 

 nal number 2.5"2o. 



AVi'll-inade skin in <.'()()(1 condition; .skull jK^rtVct. 



Microtus serpens Merriam. Biological Sui'vcy collectif)n. 



Proc. Biol. Soc. Waf^h., XI, i*. 75, Aj.ril 21, 1897. 

 76303. Skill and skull. Adult male. Agassiz, British C'oluinltia. 

 December 2. LSS)5. Collected by C. P. Streator. Orio-ina! nuin- 

 ))er :>m)S. 



Well-made skin in <;ood condition; skull ])erfect, except for siijxht ju'rforation 

 in ])rain case. 



Microtus sitkensis Merriam. Biological Survey collection. 



Proc. Biol. Soc. Wash., XI., p. 221, July lo, 1897. 

 73839. Skin and skidl. Young adult male. Sitka, Alaska. August 



3, 1895. Collected l)y C. P. Streator. Original number 4745. 

 Well-made skin in jrood condition; skull perfect. 



Arvicola trowbridgii Baird. 



Mammals of North America, p. 529, 1857. 

 = Microtus californicus (Peale). See Bailey. North Amer. Fauna, No. 17, p. .So, 

 .June 6, 1900. 



T'Vs'i- Mounted specimen and skull. ]\Ionterey, California. Col- 

 lected by Lieut. W. P. Trowbridge, U. S. A. Catalogued January 



4, 1855.' 



The mounted specimen is a poor-looking object, with patches devoid of hair on 

 eacli side. The skull is in fair condition; both malars, left pter\-goid, and right 

 last lower molar are missing. 



Microtus tshuktshorum Miller. 



Proc. Biol. Soc. Wash., XIII, p. 11, January :!1, 1899. 

 sVeiVi- In alcohol, skull removed. Adult female. Plover Bay, east- 

 ern Sil)eria. Collected by Lieut. John Davison. Catalogued 

 January 12, 1S66; skull, November 10, 1898. 



Specimen is fairly well preserved; hair rather loose, and a considerable patch 

 on right side devoid nf hair: skull perfect. 



Microtus umbrosus Merriam. Biological Survey collection. 



Proc. Biol. Soc. Wash., XII, p. 107, April :;0, 1898. 

 68480. Skin and skull. Adult female. Mount Zempoaltepec, Oax- 

 aca, Mexico. July 10, 1894. Collected by E. W. Nelson and E. A. 

 Goldman. Original number 6412. 



Well-made skin in good condition; skull i)erfect. 



