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 MS in rtifa ; 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 <-/m/w/<r.x. Small upper premolar very large, at least twice as 

 large as in rufa or major, molars actually as large as relatively much 

 larger than in rufa. 



Meaxiii'tmt-ntx. 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 f^f <^ ad. Merriam 

 Coll. Collected August 1, 1886, by C. A. Allen. Grig. 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 rufa ; zygomata spreading but less bowed out than 

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

 angle ; rostrum slender ; nasals short, abruptly narrowed posteriorly, and 

 ending considerably in front of posterior plane of prema^illse ; interorbital 

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

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

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

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



Measurements. Type specimen: Total length 330; tail vertebra? 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, 1897, by R. T. Young. Original No. 309. 



diameters. 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 A. olympica differs from that of A. rufa 

 in the following characters : interorbital constriction decidedly narrower 

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

 the narrowest of the rufa series) ; zygomata standing out more strongly 

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

 panded but developing a postorbital ridge or process which forms the 

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

 formed by the thickened anterior end of the squamosal, being absent ; 

 audital bailee, particularly the long bony tubes, much smaller; auditory 

 meatus much smaller and more nearly a complete circle, with notch on 

 upper side smaller and narrower. 



Measurements. Type specimen: Total length 350; tail vertebrse 35; 

 hind foot 55. 



