222 VERTEBRATE REMAINS, PORT KENNEDY BONE DEPOSIT. 



the line of the anterior border of the last' inferior molar. The inferior border is 

 flared out below it, descending to the external plane of the ramus below the middle 

 ofthe second molar. This character is best seen in a separate ramus to be referred 

 to later. 



The superior incisors are perfectly preserved in a nearly complete left premax- 

 illary bone, which is adherent to a part of the maxillary which contains the left 

 canine ; and they are less perfectly preserved in a left side of the face which contains 

 nearly all of the teeth. The large external incisor has a triangular section at the 

 base ofthe crown. The apex is turned a little externally but the base is continued 

 as a ledge close to the second incisor from the posterior to the anterior face of the 

 crown. The anterior face of the crown is not grooved, but there is a sharp longi- 

 tudinal groove dividing that of both of the other incisors. 



The superior canine is very robust, especially at and below the base of the 

 crown. The latter is compressed oval in section, and has rounded anterior and 

 posterior faces, with or without a fine median keel. There is a ridge-like ledge on 

 the internal side of the crown, just posterior to the plane of the anterior border. 

 The anterior three premolars are one-rooted. The (irst is the largest, and has a 

 short, obtuse and compressed crown ; it is situated close to the canine. The third is 

 close to the fourth, while there is a short space anterior and posterior to the third. 

 The fourth or sectorial has two subequal cusps, the anterior more conic, the posterior 

 more compressed. The internal cusp is a well-developed cone which is less elevated 

 than the external cusp, and is opposite the emargination between them. Both this 

 tooth and the two superior true molars are biconvex externally, the groove of the 

 external wall marking the posterior boundary of the metacone. The first true molar 

 has a parallelogrammic outline, the long diameter anteroposterior. The metacone 

 and ectocone are subequal and more elevated than the protocone and hypocone. A 

 curved ledge extends from the protocone forward and outward to a small paracone, 

 which is appendicular to the metacone in front. The protocone is opposite the 

 posterior part of the metacone, and, like the hypocone, is strongly compressed. As 

 in U. simus and the South American forms, there is a series of broad obtuse conules 

 on the middle of the grinding surface of the crown. The anterior is opposite the 

 metacone, the middle opposite the space between the latter and the ectocone, and the 

 posterior near the posterior border of the crown. These conules do not occur in the 

 species of the group No. 2 of the key given above. The last or second true superior 

 molar is remarkable for the recurvature of the grinding face at its posterior 

 extremity nearly to the base of the crown. This tendency is exhibited by several 

 species of bear, but it is nowhere carried so far as in the present one. The protocone 

 is represented by the internal angular border of the crown, which continues as an 

 inconspicuous ledge around the anterior border to the anterior base of the metacone. 

 The latter is an angulate ledge compressed to a crescent-shaped edge. It is sepa- 

 rated by a transverse fissure from the similar but every-way smaller ectocone. The 

 hypocone is a slight prominence of the border of the crown. The heel, measured 



