392 PROCEEDINGS OF THE ACADEMY OF [1896. 



This species differs from Liitra canadensis in two conspicuous 

 points ; first, the inferior border of the mandible is a nearly straight 

 line to the angle ; second, the third premolar is nearly transverse to 

 the long axis of the jaw in position, in consequence of the much 

 shorter mandibular symphysis. 



The coronoid process is at right angles to the horizontal ramus 

 and its anterior and posterior borders are straight and of equal in- 

 clination to the obtuse apex ; the posterior border is convex in L. 

 canadensis. The angle is opposite the base of the sectorial ; in 

 L. canadensis, it is opposite the apices of the cusps of the sectorial. 

 The anterior border of the masseteric fossa is below the middle of 

 the tubercular molar. The inner side of the ramus is flat and not 

 grooved, except immediately above the angle. The mental foramina 

 are below the middle of the first, and the anterior root of the second 

 premolars. 



Both the internal and external borders of the inferior tubercular 

 molar are elevated, the former as a low cusp. The crown is hori- 

 zontal in position and is not tipped forward as in L. canadensis. 

 An external basal cingulum on both this tooth and the sectorial. 

 In the latter the metacouid is well developed ; the protoconid and 

 paraconid are broken away. The basin of the heel has the form of 

 of that of L. canadensis, and the external cutting edge is notched 

 in front. The first premolar is longitudinal in position, but the 

 anterior root of the second premolar is interior to the middle line. 

 The internal root of the third premolar is near the middle of the 

 superior face of the ramus, but the interior root is anterior to the 

 internal border of the anterior root of the second premolar. Both 

 are close to the canine alveolus. The crown of a premolar was dis- 

 placed and adherent in the alveolus of the root of the paraconid of 

 the sectorial. The crown probably belongs to the second premolar. 

 It has no lobe on its posterior edge, and is expanded posteriorly at 

 the base. The superior tubercular has lost its paracone and meta- 

 cone. The interior part of the crown is a broad table with the 

 protocone as an obtuse cusp on the interno-anterior border, with a 

 cingulum at its base. This part of the tooth is much like that of 

 L. canadensis, but is not so convex posteriorly. 



Unoia mercerii Cope. Proceeds. Academy Nat. Sciences Phila., 1895, p, 448. 

 Crocuta inexpecUtta Cope, 1. c, ji. 449. 



Additional material of this large feline confirms its distinctness. 

 The sectorial tooth referred to the genus Crocuta as above cited, 



