!20 Merriam — Descriptions of Six New Rodents. 



skull IS decidedly smaller and narrower, the rostrum longer and much 

 more slender ; the zygomata very narrow, not spreading or bowing out- 

 ward as in rafa ; audital tubes very much more slender and much shorter ; 

 frontal platform between orbits and rostrum (seen from above) very 

 much smaller, narrower, and more rounded laterally— less flattened. 



Denial cha7-aciers.— Small upper premolar very large, at least twice as 

 large as in rnfci or major, molars actually as large as— relatively much 

 larger than — in rufa. 



Measurements. — Type specimen: Total length 304; tail vertebrae 22; 

 hind foot (in dry skin, moistened) 48. 



Aplodontia phaea sp. nov. 



Type from Pt. Reyes, Marin Co., California. No. ||f| (^ ad. Merriam 

 Coll. Collected August 1, 1886, by C. A. Allen. Orig. No. 142. 



Characters. — Size small; coloration (in July and August specimens) re- 

 markably uniform grizzled bister brown without rufous or fulvous; ears 

 much smaller (shorter) than in A. pacifica.. 



Cranial characters. — Skull of medium size, larger than that of pacifica, 

 smaller than that of riifa ; zygomata spreading but less bowed out than 

 in rufa, the anterior root standing out squarely with a well developed 

 angle ; rostrum slender ; nasals shoi't, abruptly narrowed posteriorly, and 

 ending considerably in front of posterior plane of premaxillae ; interorbital 

 region broad ; audital bulUe and tubes intermediate in size between those 

 of rufa and pacifica, the tubes of same length as in pacifica — much shorter 

 than in rvfa; incisive foramina small and compressed or 'pinched in' ; 

 small upper premolar about as in rufa — decidedly smaller than in pacifica. 



Measurements. — Type sjiecimen: Total length 330; tail vertebrae 30; 

 hind foot (in dry skin, moistened) 55. 



Aplodontia olympica sp. nov. 



Type from Queniult Lake, Olympic Mts., Washington. No. 89549 (^ 

 yg.-ad. U. S. National Museum, Biological Survey Coll. Collected July 

 24, 1.897, by R. T. Young. Original No. 309. 



Characters. — Similar to A. rufa but larger and darker; upper parts less 

 ' reddish ' or fulvous ; nose darker ; white spot at base of ear absent or 

 poorly developed. 



Cranial characters. — The skull of .1. o/y»!^«ca differs from thatof ^. rufa 

 in the following characters : interoibital constriction decidedly narrower 

 (measuring from 8.5 to 10 mm. in 8 adults as contrasted with 11 mm. in 

 the narrowest of the r\ifa series) ; zygomata standing out more strongly 

 anteriorly with a thickened elbow at the angle; jugal not obliquely ex- 

 panded l)ut developing a post orbital ridge or process which forms the 

 only upward projection from the arch — tlie posterior projection in rufa, 

 f(jnned by the thickened anterior end of tlie squamosal, being absent ; 

 aiulital biillre, particailarly the long bony tubes, much smaller ; auditory 

 jneatus much smaller and more neai'ly a complete circle, with notch on 

 upper side smaller and narrower. 



Measarements. —Ty])Q sjiecimen : Total length 350; tail vertebra^ 35; 

 hind foot 55. 



