216 M. R. Thorpe — New Species of 



both. Its basal length is about intermediate between 

 the two species above mentioned, while the prosthion- 

 nasion dimension is bnt 3.5 mm. above that of H. 

 primcevus. The prosthion-bregma dimension is only 

 2.5 mm. below that of H. robustus. The cranial region 

 is lower than in H. robustus by 13 mm., and lower than 

 in H. primcevus by 6 mm., which gives the skull a mark- 

 edly different configuration. The bizygomatic diameter 

 is greater than that of II. robustus by 6 mm., although 

 the breadth of the anterior nares is less. Again, the 

 diameter of the postorbital processes of the frontals is 

 greater than in H. robustus by 6 mm., but the bimastoid 

 diameter is less by 1.5 mm. The palatal length is 



' Fig. 3. 



Fig. 3. — Hoplophoneus latidens, n. sp. Paratype. Eight ramus, two- 

 thirds natural size. 



12.5 mm. less than that of H. robustus. One important 

 feature is the difference in shape of the anterior zygo- 

 matic pedicle. The measurement from the inferior 

 orbital margin to the alveolar margin is 24 mm., in H. 

 robustus it is 18 mm., while the distance from the infra- 

 orbital foramen to the posterior margin of the zygomatic 

 process of the maxilla is 28 mm. and in H. robustus, 

 32.5 mm. The conventional index of these measure- 

 ments for this specimen is 117, for H. robustus, 162,5, 

 and for H. primcevus, 143. The superior canine is 

 slightly greater in its maximum diameter at the parapet. 

 The postorbital constriction is less than that of H. 

 primcevus by 3 mm. 



Summing up the broad differences of the skull, it is 

 found that this specimen, in comparison with H. robustus, 

 is shorter and broader, has a much lower parietal region, 

 and the diameter of the postorbital constriction is less 

 than that of even H. primcevus, while that of the bimas- 

 toid is about equal to that of H. primcevus and much less 



