﻿HYAENA CROCUTA. 9 



as there is in Felis (see PI. IV, fig. 1). The canines are less powerful than in Ursus and 

 Felts, and are oval in transverse section, without any longitudinal groove or angle 

 separating the inner third. Pm. 3, pm. 3, and pm. 4, the large and powerful bone- 

 crushing teeth, are very characteristic, as is the form of the carnassial teeth. The features 

 of the teeth will be now more fully described. 



(2) Permanent Dentition of the Upper Jaw (see PI. IV). — I. 1 and 2 show a 

 prominent anterior cone or cusp separated by a groove from a depressed posterior area, 

 which is divided by a second groove into right and left cusps. These teeth have wide 

 laterally compressed and somewhat squarely truncated roots. 



I. 3 is a much larger caniniform tooth, with a marked ridge specially developed antero- 

 externally where it encroaches on the crown. The root is massive and subcylindrical. 



C. The canine has the usual form. Its crown forms about one third of its length, 

 and is not traversed by grooves, as in the Felida?. It is thickest in the middle, and 

 tapers nearly as rapidly towards the end of the root as towards the tip of the crown. It 

 is not always easy to distinguish between an upper and a lower canine, but Dawkins 

 remarks that the upper differs from the lower by the absence of the lateral curvature 

 of the root. 



Pm. 1 is a small one-rooted tooth. Its crown forms a low, somewhat incurved cone 

 traversed by a longitudinal ridge. 



Pm. 2 is a stout tooth with a low cone and small accessory cusps placed internally 

 and posteriorly. The base of the crown is surrounded by a well-marked cingulum, and 

 the tooth is fixed in the jaw by a pair of stout, subequal, and only slightly divergent roots. 



Pm. 3 is a far larger and stronger tooth than pm. 2. The crown forms a stout, 

 slightly incurved cone. The cingulum is strongly developed, and is much thickened 

 posteriorly and antero-internally, sometimes forming irregular cusps from which marked 

 ridges ascend the cone. The tooth forms a powerful bone-crusher. 



Pm. 4 is the upper carnassial, and is larger than any other molar or premolar tooth 

 in eitlier jaw. The long trenchant blade is divisible into three lobes : an anterior one, 

 the smallest of the three, and forming little more than a large cusp ; a middle one which 

 rises into a point ; and a posterior one which is the longest of the three, and is divided 

 from the middle one only by a deep narrow notch. On the inner side of the first lobe 

 is a large but low inner tubercle. There are three roots, two smaller ones placed side 

 by side anteriorly, and a very large laterally compressed posterior root. 



M. 1 is not represented in the British Museum set figured on PI. IV. Dawkins 

 describes it as follows •} — "Very small, equilateral-triangular, and supported by two fangs, 

 of which the anterior and outer is by far the smaller; the posterior supporting the two 

 posterior angles is enclosed in an alveolus with very delicate walls, which would soon 

 disappear by absorption after the loss of the tooth." 



(3) Permanent Dentition of the Lower Jaw (see PI. IV). — The three incisors are all 



1 ' Nat. Hist. Eev.,' n.s., v, 1865, p. 90. 

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