136 Proceedings of the Biological Society of Washington. 



Skull measurements (c? ad. type). — Basal length 326 mm.; occipito- 

 nasal length 323; palatal length 175 ; zygomatic breadth 208 ; interorbital 

 breadth 82. 



Ursus chelan sp. nov. 



Type No. 205185 cJ* old, U. S. National Museum, Biological Survey 

 Collection. From east slope Cascade Mts. , northern Chelan Co., Wash- 

 ington. (Killed in Township 30 N, Range 16 East, Willamette Meridian, 

 Wenatche National Forest. ) Collected September 1, 1913, by D. S. Rice, 

 Forest Ranger. 



Cranial characters . — External characters unknown. Skull of old male 

 (the type): Size medium or rather large; facial axis strongly deflected 

 from basicranial axis; vault of cranium well arched, highest over posterior 

 frontal region ; sagittal crest long, high, arcuate, rising anteriorly above 

 general level of top of cranium. Affinities apparently with selkirki on the 

 one hand, and with shoshone and pervagor on the other. Frontal shield 

 narrow, flattened, short pointed posteriorly, ending about midway be- 

 tween fronto-parietal suture and plane of postorbitals, slightly sulcate 

 medially; postorbital processes rather broad, flat, outstanding horizon- 

 tally (not depressed or decurved); fronto-nasal region including posterior 

 two-thirds of nasals sloping strongly, forming part of long fronto-facial 

 plane; rostrum small, short, somewhat depressed, sloping anteriorly to 

 nares, gradually rising posteriorly into frontal plane; braincase long, 

 arched, frontal part keeled into sagittal crest; palate arched antero- 

 posteriorly, slightly concave ; postpalatal shelf broad ; zygomata broadly 

 spreading, rounded and outbowed posteriorly, vertically expanded and 

 strongly arched ; mastoids of medium length, spreading ; lower jaw mas- 

 sive ; ramus swollen on outer side over roots of 2d and 3d molars, bellied 

 under last molars; coronoid blade high, its anterior border rather strongly 

 recurved, the apex overarching high coronoid notch but barely reaching 

 plane of front of condyle; teeth rather small for size of skull (so badly 

 worn in type specimen that proportions of canines can not be deter- 

 mined). 



Cranial comparisons. — Old male Ursus chelan diSers from all its rela- 

 tives in the degree of deflection of the facial part of the skull, and exceeds 

 all except selkirki in the arching of the palate. Type skull of chelan corn- 

 pared with the type skull of pervagor : Basal length slightly less; zygomatic 

 breadth greater ; frontal shield shorter-pointed and flatter ; postorbitals 

 flatter and apparently broader; sagittal crest longer, liigher anteriorly 

 and more convex; rostrum shorter and more strongly sloping anteriorly; 

 nares more truncate; zygomata more strongly outbowed, more arched, 

 more expanded vertically, squamosal arm longer (squamoso-jugal suture 

 much longer); palate shorter and more strongly arched; lower jaw 

 shorter, its inferior ramus much shorter ; coronoid blade slightly higher 

 and more falcate. Some of these diff"erences may be due to age, the skull 

 of the type of chelan being very old, while the type of pervagor is only 

 adult. However, the type of chelan differs rather conspicuously from an 



