Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/591

 Hyoena crocuta, and consequently still smaller than in Hyoena sinensis. The difference of size, however, between H. sivalensis and H. crocuta is much less than that between H. crocuta and H. striata; consequently the Siwalik Hyaena was larger than that now existing in Hindostan, although less than that which once roamed in China. In the shape of the chief cone, however, of p 3, upper jaw, H. sivalensis more resembles H. sinensis than it does either of the above- named existing species of Hyoena. I refer to the character of greater vertical convexity of the outer side of the crown of the chief cone. In the posterior talon and the antinternal ridge of enamel of p 3, H. sivalensis more closely conforms with the H. crocuta than does H. sinensis, and departs from the H. striata in a minor development of both posterior and anterior basal tubercles. The external basal cingulum is also wanting in H. sivalensis as in H. sinensis. The degree in which the Chinese Hyoena surpassed in size that from the Red Crag of Suffolk will be appreciated by comparing fig. 5, Pl. XXVIII., with fig. 6 in pl. viii. of Ray Lankester's able memoir on Hyoena antiqua, in the ' Annals and Magazine of Natural History,' third series, vol. xiii.

Differences of like kind and value are shown by the second lower premolar (p 3 of the type series) of Hyoena sinensis, as compared with H. crocuta, H. striata, and H. sivalensis. The crown is broader both antero-posteriorly and transversely, but is lower vertically, than in H. crocuta ; it is consequently a stronger cone : its qualities for cracking and crushing bone are intensified. The ridge continued upward from the anterior basal talon is stronger than in H. crocuta ; it is more completely an upward production of the talon itself; and this is less defined as an anterior tubercle than in H. striata. The superior size of H. sinensis to H. sivalensis is more marked in the comparison of the lower premolar than in that of the upper one. Besides the superiority of size, the inner side of the chief cone is more convex vertically and transversely, more bulging, in the Chinese than in the Siwalik Hyaena ; it more resembles, in this particular, the much smaller tooth of Hyoena striata.

The two fangs in both upper and lower premolars are deeply grooved along the surfaces turned towards each other; the hinder fang is entire in the specimen of the upper premolar from the cave near Chung-king-foo.

The canine has lost the apical half of its crown, but closely accords in form and in its transversely lineate back ridge with that of Hyoena. crocuta ; in size it conforms with the premolars above described.

Upper p 3. Lower p 3.

Hyoena sinensis.

H. crocuta. H. sivalensis. H. sinensis. H. crocuta. H. sivalensis.

Antero-posterior diameter

Vertical diameter

lines. 12 10

lines. 11 12

lines. 10-1/4 9

lines. 11-1/2 11

lines. 10 12

lines. 9-1/2 9-1/2