ME. a. BUSK ON THE EXISTING SPECIES OF HT.ENA. 67 



the average 644 — and in -ff. striata 590, in which species the 

 maximum is 650, and minimum 510, whilst the corresponding 

 numbers in S. hrunnea are 680, 570. Another particular in 

 which the two species differ is in the interorbital width, which is 

 considerably greater in S. hrunnea (206 to 181), the maximum 

 and minimum being in H. striata 200 and 165, and in H. hrun- 

 nea 215 and 190. The occipital condyles also, measured from 

 outside to outside, show a width of 159 in S. striata, and of 200 

 in IT. hrunnea. In the height of the orbit the two species arc 

 pretty nearly alike, and both have it considerably less than H. 

 crocuta. The nasals are smaller in H. striata than in H. hrunnea, 

 in which species those bones are larger even than in S. crocuta. 

 Passing to the maxilla we find that the width measured from the 

 outside of the 3rd premolars is in H. striata 308, and in H. hrxmnea 

 350 (the maximum in the former species being 335, and in the 

 latter 380), whilst' the least transverse measure of the upper jaw 

 in H. striata is 198, ^nd in H. hrunnea 221, showing that in tlie 

 latter case it is rather more constricted in front. Again, passing 

 on to the teeth, the length of the upper incisor series in H. striata is 

 on the average 127, and in H. hrunnea 139; but when looking to the 

 maximum and minimum in each case, it will be seen that no -h&xj 

 great difference in this particular really exists. With respect to 

 the length of the molar series, however, it is widely different ; the 

 mean figure for this in H. striata is 271, and in H. hrunnea 312 

 — the respective maxima being 285 and 320. 



As regards the individual teeth, those in which the greatest 

 differences are perceptible are the 3rd incisor, the canine, the 3rd 

 premolar, and the 4th premolar, the last two exhibiting consi- 

 derably greater dimensions in H. hrunnea. 



In the mandible a coi'responding want of size wiU be found in 

 H. striata, the maximum length of the jaw, measured from the 

 back of the condyle to the incisive border in front, being in that 

 species 660, and in S. hrunnea 740 — the condyle in the former case 

 measuring 145, and in the latter 170 in transverse diameter. And 

 the other dimensions of the mandible are in agreement with these, 

 as will be seen from the Table. 



As to the teeth, the lowerincisor series isof about the same length 

 in both species ; but the molar series, as a matter of course, cor- 

 responds with that of the upper jaw in its gi'eater length in H. 

 hrunnea (309 to 268, or in the maximum, 320 to 288). The third 

 incisors are about equal, but the canine is considerably larger in 

 H. hrunnea— -the maximum size of that tooth in B. striata being 



7* 



