226 MEMOIRS OF THE UNIVERSITY OP CALIFORNIA. 



The palate is relatively broad, and the posterior palatine foramina are set 

 relatively far back. The posterior end of the vomer extending backward between 

 the vertical plates of the palatines commonly reaches very slightly beyond the 

 posterior nasal opening. This is in decided contrast to the Recent wolves, in 

 which the broad posterior end of the vomer reaches well beyond the posterior 

 nasal opening. In most of the specimens of Canis dims the posterior nasal 

 opening is relatively wider at the anterior end than in wolves of the C. occi- 

 dentalis type. 



The occipito-sphenoidal region of the skull exhibits a tendency to shortening, 

 the distance from the posterior border of the glenoid fossa to the posterior 

 side of the occipital condyles averaging slightly less than in other forms. On 

 the basal occipital the uneven surfaces corresponding to the attachment of the 

 longus capitis muscle are marked by very rough areas which commonly do 

 not extend as far forward as in the timber wolves. In other forms these areas 

 extend forward for a considerable distance anterior to the tympanic bullae. 

 In the space between the tympanic bullae and the anterior end of the inferior 

 notch of the foramen magnum the median ridge extending from the basal 

 occipital to the basal sphenoid is usually relatively prominent and acute, while 

 in the timber wolves it is commonly a low, broad, horizontally truncated ridge. 



The posterior aspect of the skull presents in general a very different form 

 from that of the Recent wolves. The two ridges which form the lamboidal 

 crest tend to converge sharply above the occiput, while in most Recent forms they 

 sweep outward rather widely before uniting at the inion. On the other hand, 

 the short processes formed at the lower ends of the transverse ridges and 

 immediately behind the superior side of the posterior root of the zygomatic 

 arches average smaller than in the modern species. In the superior region of 

 the occiput the two lateral depressions in which the attachments of the rectus 

 capitis posticus are situated average extraordinarily deep, and are separated 

 by a narrow ridge which is relatively prominent with reference to the occiput 

 as a whole. The backward projection or overhanging of the inion is extraor- 

 dinary, as are also the height and thinness of the sagittal crest rising above it in 

 posterior view. 



The lower jaw tends to be relatively longer than in most wolves and is also 

 relatively higher and thicker below the inferior carnassial. Although the coro- 

 noid process is not unusually high, the masseteric fossa is generally very deep 

 and rough, indicating an unusually strong muscular attachment. 



Although the foramina of the skull do not in general vary greatly in form or 

 position from those of the Recent species, certain minor modifications are 

 usually noticeable. The posterior palatine foramina are commonly situated 

 farther back than in the Recent American species, and are nearly opposite 

 the posterior borders of the superior sectorials. The openings of the optic 

 foramen and the anterior lacerated foramen are situated very near together in 



