86 Miller — Synopsis of the Voles of the Genvs Phenacomys. 



Teeth. — The teetli of Plienacnmi/s longicaudus differ from those of the 

 other species in the reduction in width of the inner triangles of the upper 

 molars. This tendency is especially marked in the posterior inner tri- 

 angles of the first and second teeth. In these tlie anterior face of the 

 prism is nearly parallel with the anterior side of the second external re- 

 entrant angle. The anterior transverse loop of the posterior upper molar 

 is narrower tlian in other members of the genus and the tei-minal loop of 

 the same tooth is considerably shortened. In the lower jaw the enamel 

 pattern shows no characters beyond a general tendency to narrowness of 

 all loops and triangles. 



Measuremctits.— Type specimen "(from skin): total length, 148; tail 

 vertebra', 58; hind foot, 20.2" (True). Lane County si)ecimen : total 

 length, 165; tail vertebrae, 63; hind foot, 20.8 (from fresh specimen )jy 

 the collector, A. Todd). 



General, reniarks. — I'henaromiis longieaiidni< differs so strikingly in propor- 

 tions and color from all other inembers of the genus that it canncjt be 

 compared with any. Its appearance is unique among the voles, though 

 faintly suggested by some of the Asiatic species of A/ticola. 



BiBMOGKAPHY OF TlIK GkNCS PhEXACOMYS. 



1889. Merriam, C. Hcirt. — Description of a New Genus {Phenacomys) and 



Four New Species of .lr/7'co///*a'. <North American Fauna, No. 2, 

 pp. 27-35, pi. ii-vii. October 30, 1889. Genus defined and four 

 species named, P. intermedins, P. celatus, P. latimanus, and P. 

 ungava. 



1890. True, F. W. — Description of a New Species of Mouse, Plicnacomys 



loiigicaudus, from Oregon. <Proc. U. S. National Museum, xiii, 

 pp. 303, 301. Author's separates issued November 15, 1890. 



1891. Merriam, C. Hart. — Results of a Biological Reconnoissance in South- 



central Idaho. <North American Fauna, No. 5, pp. 1-114. 

 July 30, 1891. Plienacomgs oroptuliis described on pages 65, 66. 

 1891. Todd, Aurelius. — An Oregon Mouse. <We.st American Scientist, 

 vii, pp. 240-242. September, 1891. Account of the arboreal 

 habits of Phenacomgs longicaudus and copj' of original descrip- 

 tion of the species. 



1891. Flower, William H., and Lydekker, R. — An Introduction to the 



Study of Mammals, Living and Extinct. Genus Phenacomys 

 mentioned on page 466. 



1892. Merriam, C. Hart.— The Geographic Distribution of Life in North 



America with Special Reference to the Mammalia. <Proc. 

 Biological Soc. Washington, vii, pp. 1-64. April, 1892. List of 

 species of Phenacomys on page 25. Arvicola. boreaUs Richardson 

 provisionally referred to this genus. 

 1894. Nehring, A. — [Review of North American Fauna, Nos. 1-5.] 

 ■<Naturwissenschaftliche Wochenschrift, Berlin, p. 346. July 

 15, 1894. Bones from cave in southern Hungary referred to the 

 genus Phenacomys. 



