W.B. Davis 1935. Mammals examined from Idaho in the Chas. R. Conner Mus, Pullman, Wash. 459. Nov. 20, Thomomys (continued) last two teeth when viewed laterally as opposed to all of them being visible in fuscus). 7. Color much darker and more concentrated. Dorsal surface of tail brownish, that is, distinctly bicolor, as compared with Ellis' material the same cranial differences are found, but the difference in color is not so great. However this specimen is more chestnut than any of Ellis' material. 2659 Oldav Mts., W.S.C. Camp, 4000 ft.; coll. May 12, BeakLg H. 26. 9. Interorbital 6. 4 Zygo Br. 17. 9 L. Nasale 12. 0 B. Rostrum 6. 1 L. Rostrum 14. 4 May. Tooth R 6. 8 Mastoid br. 16. 7 Depth of skull 11. 7 1923 by W.T. Shaw; 177-49-23. Color not quite so concentrated as in above. However, darker than topotypes) of fuscus). No skull, tail bicolor at basal ½, distal ½ white, adult with 4? pair of mammae. Premaxillae project ½ mm. beyond nasals & are as broad as posterior part of nasals; character 6 holds in this skull, too. 9067 Near Cal de Sac; coll. April 16, 1927 by G. M. Jones. Found dead in road; 195-56-22. Measurements indicate adult, but no mammae visible). No skull.