150 Proceedings of the Biological Society of Washington. 



Old female (No. 205162) from St. Clair River, Yukon, collected Sept. 

 6, 1914, by A. Hoyt: Size very small; frontal shield remarkably broad 

 for so small a skull, convex and medially sulcate interorbitally ; fronto- 

 nasal region strongly dished; postorbitals small, outstanding; rostrum 

 short and depressed ; palate and postpalatal shelf short and broad ; 

 zygomata rather strongly outstanding, subtriangular. Lower jaw very 

 small and light; coronoid moderate, apex strongly recurved; teeth very 

 small, nearly as small as in nelsoni. 



Cranial comparisons. — Old male pallasi (the type) compared with old 

 male kluane (the type): Size decidedly smaller; skull about an inch 

 shorter and much less highly arched, with conspicuously shorter brain- 

 case and shorter sagittal crest; crest nearly straight instead of strongly 

 arched; postorbitals very much smaller, narrower, and less strongly de- 

 curved ; f ronto-nasal region much less elevated and more dished ; rostrum 

 much lower, depressed above instead of rounded ; palate much shorter, 

 less arched and less concave; lower jaw much shorter; coronoid lower. 



Adult female pallasi compared with adult female kluane: Size of skull 

 essentially the same or slightly smaller; canines smaller; molars very 

 much smaller. 



Skull measurements ( c? old, type). — Basal length 302.5 mm. ; occipito- 

 nasal length 279 ; palatal length 159 ; zygomatic breadth 209 ; interorbital 

 breadth 72.5. 



Ursus Selkirk! sp. nov. 



Type No. 205170 c? old, U. S. National Museum, Biological Survey Col- 

 lection. From Upper Columbia River, Selkirk Mts., B. C. Collected 

 June 4, 1914, by John Hurst. 



Characters. — Size medium or rather small ; skull long, low, flat, and 

 narrow; naso-frontal region elevated, sloping in same plane with frontal 

 shield ; postorbitals broadly subtriangular. 



Cranial characters. — Frontal shield narrow and flat, sloping gradually 

 into rostrum, only faintly depressed interorbitally, rather long-pointed, 

 ending posteriorly about 20 mm. in front of parietals ; postorbital pro- 

 cesses flat, very broad, concave anteriorly, convex posteriorly, not widely 

 projecting ; rostrum rather narrow, slightly rising posteriorly in frontal 

 plane ; nasals slightly elevated anteriorly ; sagittal crest short ; palate 

 arched anteroposteriorly and concave transversely; postpalatal shelf 

 broad and flat; zygomata moderately spreading, subtriangular; mastoids 

 rather short ; lower jaw rather weak ; coronoid blade low, the apex 

 abruptly recurved, defining a rather short coronoid notch. 



Cranial characters of old female, assumed to be selkirki. No. 203162 fe- 

 male old, Wallowa Mts., Oregon. Collected May, 1909, by J. K. Carper 

 and J. T. Jardine. — Size rather large in relation to male; cranium low 

 and flat; frontal shield medium, flat (slightly depressed medially), the 

 point ending at fronto-parietal suture; postorbitals large, rather broad, 

 and horizontally outstanding; rostrum rather narrow, high, and short; 

 zygomata subtriangular ; postpalatal shelf broad and flat ; ramus of jaw 



