322 ME. T. ATTHEY OX ANTHEACOSATJEIJS ETJSSELLI. 



united to the dentary in front ; from its upper margin arises a 

 low, rather rounded, coronoid process, and from its upper and 

 posterior part the articular process, bearing the glenoid cavity 

 for the reception of the condyle of the cranium. This cavity is 

 supported by the descending process, which forms the posterior 

 edge of the ramus, and articulates below by a broad surface with 

 the angular piece. The articular cavity faces upwards and some- 

 what inwards and forwards ; it measures two inches and a quar- 

 ter in length, an inch in width, and two-tenths of an inch in 

 depth. Its neck is strong and devoid of postarticular processes. 



Third, the angular. This, from its suture with the articular, 

 extends along to the anterior end of the ramus, forming its lower 

 border and the remaining half of the symphysis. It articulates 

 by its upper edge with the splenial behind and at about the 

 middle of its length, and with the dentary in front. 



Fourth, the splenial. This lies along a great part of the inner 

 surface of the ramus, attached along the upper edge to the arti- 

 cular and the dentary pieces ; below, both behind and in front, 

 it is connected with the angular, in conjunction with which it 

 forms two unequal elliptical openings, the anterior much less 

 than the posterior, which during life were filled by membrane ; 

 these openings are separated by a long obliquely descending- 

 process of the splenial, which articulates with a small upward 

 projection of the angular: thus the splenial has three connexions 

 with the angular piece. 



The inner surface of the right ramus of the mandible is repre- 

 sented in Plate VIII. fig. 1, one third of the natural size. 



It measures sixteen inches in length, and, at four inches in 

 front of the posterior margin, four inches and three-quarters in 

 breadth. It bears nineteen teeth, nearly all of which are in a 

 good state of preservation. The first in front is half an inch in 

 length; the second and third are a little longer; and the fol- 

 lowing thirteen are three-quarters of an inch, the last three 

 being somewhat shorter than that. 



The teeth succeed each other as follows : the first is a quarter 

 of an inch behind the anterior termination of the ramus, the 

 second an inch and a quarter behind the first ; at the same 



