10 



back of, the posterior molars. This terminal shelf, representing the 

 emargination between the pterygoids, is always broad and quite trans- 

 verse ; but the edge varies greatly in detail. It is commonly transverse, 

 with a small median, backwardly-projecting point, producing a double 

 emargination. It may be simply a broad curve, or it may present a 

 median nick. The latter case is oftenest observed in specimens from 

 the West, and constituted a chief character upon which M. occidentalis 

 rested ; but, with a larger series than Professor Baird examined, it is 

 shown to be wholly fortuitous. The general shape of the palate is tri- 

 angular; including the teeth, its greatest width behind is about as 

 much as its length ; anteriorly, it presents broad but short incisive fora- 

 mina, scarcely reaching opposite the molars. The depth of the pterygoid 

 emargination is considerably less than the length of the palate. The 

 pterygoids are simply laminar, with strongly hamulate ends. They are 

 usually parallel, but sometimes converge a little posteriorly, making 

 the inclosed space club-shaped. The general surface of the base of the 

 skull behind is quite flat, owing to slight inflation of the bullae. These 

 are decidedly convex only at one place, interiorly, elsewhere flat, and 

 outwardly produced to form a tubular meatus. Traces of separation 

 from surrounding parts long persist ; at least, in front. About the bullte 

 are seen the following foramina: one in advance, just inside the 

 glenoid fossa; two at the anterior extremity of the bulla; three along 

 its inner border ; one more exterior, near the mastoid ; one far posterior, 

 in the occipital. The basi-sphenoid suture, early obliterated, is straightly 

 transverse in advance of the middle of the bullie. The general basilar 

 area is flat, narrowing forward, unmarked, or with merely a slight median 

 ridge. The border of the foramen magnum represents a deep emar- 

 gination of the posterior border of this area, with the condylar pro- 

 tuberance on either side. 



All the bones of the skull finally co-ossify, excepting, of course, the 

 mandible, and most are joined at a comparatively early age. The 

 periotic and iuternasal sutures persist the longest ; the latter after the 

 nasals are consolidated with the maxillaries, and the former after the 

 basi-spheno-occipital suture is obliterated. When found separate, the 

 nasals are seen to be regularly concave along their exterior border, 

 truncate anteriorly, with a produced anterolateral corner, and received 

 by a pointed process in a recess of the frontal. The inter maxillar}^ 

 bone forms less than half of the general naso-maxillary suture. The 

 maxillary extends within a short distance of the supraorbital protuber- 

 ance. The malar is rather small, and fuses early with the rest of the 

 zygomatic arch. The occipital bone is rather late to co-ossify ; the supra- 

 occipital is then seen to represent most of the lambdoidal crest, reaching, 

 on either hand, from the median line half-way to the mastoid process ; 

 thence crossing this crest to the paroccipital, whence the suture runs on 

 the floor of the skull along the border of the periotic by the foramen 

 lacerum posteriusto the basl-sphenoid; thence straight across the median 

 line. 



The lower jaw in MepldtinK is never locked, as far as known, in the 

 glenoid by the clasping of the condyle in the embrace of the fossa, as is 

 the rule, in adult life, in Meles and in Taxidea, and as sometimes occurs in 

 the Otters, {Lutrince.) The ramus of the mandible is stout, and nearly 

 straight along the tooth-bearing portion ; the symphysis is thick, short, 

 abruptly ascending obliquely forward. Between the ramus proper and 

 the angle of the jaw, the lower border is decidedly emarginate, and the 

 angle itself is scarcely or not at all exflected {qf. Conejyatus). The angle 

 itself is obtuse, and there is a decided neck in the outline thence to the 



