420 



CARNIVORA 



buffy grey or yellowish under fur, the two elements of the 

 pelage distinct and not intimately blending, the black more pre- 

 dominant in winter than in summer, the exact shade of underfur 

 ranging from a light buffy grey with pale ecru-drab bases to 

 the hairs to a clear buff-yellow throughout ; middle of belly 

 usually like back and sides and conspicuously lighter than inter- 

 crural region and chest ; chin, interramia and upper lip to 

 muzzle pad whitish tinged with buffy grey, this light area, some- 

 what dulled by admixture of brownish hairs, extending upward 

 posteriorly as a broad band running between ear and eye 

 (usually not reaching latter) and across forehead, where it curves 

 slightly forward ; face in front of light band dark brown to 

 muzzle ; ear whitish grey, the orifice covered by a tuft of dark 

 brown hairs. 



Skull. — The skull is robust and strongly built, rather flat, 

 with short rostrum, short, broad brain-case, and long, nearly 

 parallel-sided postorbital constriction. D.orsal profile nearly flat 

 from slightly overhanging lambda to between postorbital 

 processes, then abruptly bent downward at an angle of about 

 30°, the slanting portion less than half as long as the horizontal. 

 Occiput squarely truncate, the condyles sometimes visible from 

 above, sometimes concealed by the lambdoid crest. Brain-case 

 ovate when viewed from above, its outline obscured by the 

 strongly developed angularly projecting mastoid region ; sagittal 

 crest low or obsolete except in fully adult individuals, joining 

 lambdoid crest at middle of a shallow median concavity in out- 

 line of latter ; lambdoid crest well developed, slightly over- 

 hanging. Floor of brain-case with slight median longitudinal ridge 

 and shallow lateral depressions ; a transverse depression in front 

 of lip of foramen magnum. Auditory bullae moderately inflated, 

 especially along inner edge, about three-quarters as wide as long ; 

 the general outline triangular with anterior border shortest, the 

 meatus not tubular ; anterior extremity of bulla not in contact 

 with hamular, and separated from foramen ovale by an oblique 

 ridge which is marked off from glenoid process by a deep 

 conspicuous notch, the distance between bulla and foramen 

 about one-third that between foramina. Postorbital region form- 

 ing a conspicuous nearly parallel-sided neck between brain-case 

 and postorbital processes, a character peculiar to this species and 

 to Lutra lutra among European Mustelidse. Interorbital region 

 slightly broader than rostrum, moderately convex longitudinally, 

 a little more convex laterally ; postorbital processes short but 

 distinct, directed slightly backward. Rostrum short and heavy, 

 the width across canines equal to distance from gnathion to 

 anteorbital foramen. Orifice of anteorbital foramen moderately 

 large, over anterior root of carnassial, and wholly beneath 

 anterior rim of orbit, the plate dividing foramen from orbit fully 

 as wide as foramen. Zygomata compressed, moderately spreading, 

 widest apart posteriorly, the orbital process short but distinct, 



