160 ON TWO NEW SPECIES OF DORCOPSIS. 



Looking at the base of the skull of D. Mackayi, we see a 

 similar disposition of the 8 palatine folds to that of D. Beccarii. 

 The arrangement of the teeth of the upper jaw forms in the former, 

 less curved lines than in the latter, only the two posterior (4th) 

 molars standing a trifle nearer together than the two third molai's 

 of the same jaw. 



The lateral incisors are here also in proportion much smaller 

 than the median ones, the second lateral a little lai'ger than the first. 



The canines are of about the same size as the first lateral incisor, 

 but longer and much more pointed. The distance from the canine 

 to the premolar is 3 times the distance from the canine to the 

 posterior incisor. 



The breadth of the Premolar surpasses by a little the breadth of 

 the first and second molar together. On the internal surface the 

 posterior portion of the premolar presents a small roundish inflec- 

 tion of the size of a pins head. 



In the lower jaw, the incisors are narrow. The lyremolar com- 

 paratively smaller than in the upper jaw, its breadth being equal 

 to that of the first molar and a part of the second (corresponding 

 to the anterior portion of the tooth to the ridge of the second, or 

 posterior cusp). The posterior portion of the cutting edge is 

 elevated, a triangular tubercle which gives the tooth a characteris- 

 tical aspect, difierent from the lower premolars of other species of 

 Dorcopsis. 



EXPLANATION OF PLATE. XX. 



Fig. 1. — Skull of Dorcojysis Beccarii Maclay, from above. 

 Fig. 2. — A part of the same skull to show the dentitioa aud the palatine fold. 

 Fig. 3. — Under jaw of the same skull. 

 Fig. 4. — Sideview of both jaws of the same. 

 Fig. 5. — Skull of Dorcojjsis Macleayi Maclay, from above. 

 Fig. 6. — Palatine fold and dentition of the upper jaw of the same skull. 

 Fig. 7. — Under jaw of the same. 

 Fig. 8. — Side view of both jaws of the same. 



Fig. 9, — Diagram showing the direction of the hair on the neck of Dorcopsis 

 Macleayi. Centre of irradiation, 

 f All the tigures, with the exception of fig. 9, natural size. 



