1916] Taylor: Two New Aplodontias from North America 499 



four (no. 94348, Biol. Surv. Coll., and nos. 6822, 6824, and 6825, Mus. 

 Comp. Zool., all taken by A. C. Brooks) from Chilliwack, British 

 Columbia; one (no. 6823, Mus. Comp. Zool., taken by A. C. Brooks) 

 from Mount Baker Range, British Columbia; one (no. 7388, Field 

 Mus. Nat. Hist., taken by L. M. Turner) from Ravenna, Washington; 

 three (nos. 3749-3751, Mus. Vert. Zool., taken by Prank Stephens) 

 from Renton, near Seattle, Washington; four (nos. 7385-7387, Field 

 Mus. Nat. Hist,, taken by E. C. Starks, and no. 3748, Mus. Vert. Zool., 

 taken by Frank Stephens) from Seattle, Washington. 



Measurements. — Of type (adult female): total length, 330 mm.; 

 tail, 25 ; hind foot, 55 ; basilar length, 59.1 ; length of nasals, 26.7 ; 

 width of nasals, 11.7; length of audital tube, 19.6; length of incisive 

 foramen, 7.2; zygomatic width, 57.5; greatest width of interpterygoid 

 fossa, 5.3 ; mastoid width, 52.5 ; alveolar length of superior cheek teeth, 

 19.6; distance between infraorbital foramina, 15.2; mandible, trans- 

 versely across angular process, 22.3 ; greatest length of mandible, 49.5. 



Remarks. — Aplodontia rufa grisea of the Puget Sound and Sumas 

 districts is apparently nearest to A. r. olympica of the Olympic 

 Mountain region. The characters of the Puget Sound form intergrade 

 not only with those of A. r. olympica but also with those of J., r. rufa 

 of the lower Columbia River. 



Specimens referred to Aplodontia rufa grisea from Sumas, Chilli- 

 wack, and the Mount Baker Range, British Columbia, show tendencies 

 toward greater dimensions in some respects, and are otherwise un- 

 typical, indicating a slight geographic variant in that region. 



Although Aplodontia rufa grisea is not strongly marked at best, 

 its relationships would seem to be indicated more accurately by its 

 recognition as a subspecies of rufa than by its direct reference to that 

 form. 



Aplodontia californica columbiana, new subspecies 

 British Columbia Mountain Beaver 



Type.— Male adult; no. 1899, Coll. E. A. and 0. Bangs, Mus. Comp. 

 Zool.; Roab's Ranch, Hope, British Columbia, June 14, 1894; col- 

 lected by W. C. Colt; stuffed skin, with skull and jaws, in good con- 

 dition, except skin with foreleg injured in trap, skull with left audital 

 tube, region of foramen magnum, and hamulars somewhat injured. 



Diagnosis. — Similar to Aplodontia californica rainieri, but larger; 

 males having white patches beneath; nasals tending to be longer and 



