412 



U. S. P. R. R. EXP. AWD SURVEYS ZOOLOGY GENERAL REPORT. 



List of specimens. 



i Light yellowish red: D. ordii. 

 s More dusky : D. montamu. 



3 Dusky ; white tip to the tail ; type of Dipodomyt montamu. 



4 Rather dusky; tail dusky at the end. 

 6 Probably near Santa Catarina. 



DIPODOMYS PHILLIPII, Gray. 



Dipodomys phiUipii, GBAY, Annals and Mag. Nat. Hist. VII, 1840, 521. IB. Sill. Am. J. So. XLII, 1842, 335. 



(Real del Monte.) 



WAGNER, Suppl. Schreb. Ill, 1843, 295. 

 LECONTE, Pr. A. N. Sc. VI, 1853, 224. (San Diego.) 

 Dipodomys ptiittippsii, ACD. & BACH. N. Am. Quad. Ill, 1853, 137 ; pi. cxxx. (The figure derived from Gray's 



specimen ; description uncertain.) 



? Macrocolus hahicus, WAGNER, Wiegm. Archiv, 1846, i, 172. IB. Abhandl. K. Baier. Akad. XXII, 1845, 319. 

 GIEBEL, Saugt. 1855, 599. 



Above yellowish brown. Tail very long, much exceeding the body ; the upper caudal dusky 

 stripe extending to the tip, although the hairs here are only dusky at their extremities, the 

 principal portion being white ; in some specimens entirely white, the lower stripe becoming 

 obsolete near the tip. 



Two specimens of what I refer to this species were caught at Posa creek by Dr. Heermann and 

 preserved. They are in the state of moult or change of hair, and it is consequently impossible 

 to describe accurately their color. The essential conditions of the species appear to consist in a 

 thin tail, much longer than the body, the hairs quite close pressed till on the terminal third, 

 when they gradually elongate on the upper side to the tip, where they measure an inch in 

 length. They elongate somewhat on the under side near the tip, but do not stand out in a 

 crest as on the upper. 



