224 DR. R. W. SHUFELDT ON [Apr. 1, 



found a short longitudinal gutter with a foraminal pit at either end 

 of it, Meckel's cartilage, as usual, is eiislieathed by the anterior 

 portion of the articular element of the mandible, from whence it 

 proceeds forwards to the symphysis, being exposed along the inner 

 side of the dentary for its anterior moiety. The umjular, pointed 

 behind and truncated in front, occujiies nearly the middle third of 

 the ventral border of the ramus. The two bones thus far alluded 

 to are designated by Hoffmann as the articulare and the a7i(julare, 

 respectively. And it is my intention in the present connection to 

 use the nomenclature for the ramal elements given us by that 

 distinguished anatomist (see Bronn's ' Thier-Reichs,' Kept. 22-24 

 Lief. 1881, Taf. Ixvii. figs. 4-.5), as his account of these ossifications 

 is far more satisfactory than any other that I happen to have at my 

 hand at the present moment. Tlie coronoideum occupies its usual 

 position, developing upon its mid-dorsal border a strong quadrate 

 coronoid process, which takes on an upward and backward direction. 

 This element articulates with the dentale, the complementare, the 

 operculare, and the articulare. Forming the base of a fossa be- 

 tween the bifurcations of the coronoideum, upon the mesial aspect 

 of the ramus, occurs a thin splint-bone, the complementare, and this 

 is probably the " splenial " element of some authors. Beyond the 

 ossifications thus far described we find an operculare ; it is a flat, 

 irregular shaped bone that stands between the dentale on the one 

 hand and the coronoideum, complementare, and the angulare on the 

 other, forming a fair share of the mid-portion of the surface of the 

 inner aspect of the ramus. 



Still more important is the dentale, which, as we know, bears the 

 teeth. This is here cpiite a powerful bone forming the distal moiety 

 of the mandible, being markedly concaved upon its mesial aspect, 

 and correspondingly convexed both vertically and antero-posteriorly 

 on its external surface. As I have already said, the symphysis of 

 the two dentary elements is notably weak ; indeed, the bones of the 

 two sides are little more than in contact at the point in question. 



Two small foramina pierce the operculare upon its inner aspect, 

 as does one the angulare posterior to these. Externally there is 

 also an opening of this character which is found in the suture 

 between the coronoideum and the articulare, being vertically below 

 the coronoid process. 



The hyoid apparatus. — At its hinder extremity the slender basi- 

 hi/al is just sufficiently enlarged to admit of its articulation with 

 the anterior and posterior cornua. Posterior to this point it does 

 not send back any median process, while in front its delicate 

 cartilaginous rod is continued forwards into the tongue. Uj)on 

 either side of its hinder and slightly enlarged end it has articulating 

 with it the mesial heads of the anterior cornua. These latter have 

 their slender shafts at first directed, upon either side, forwards and 

 outwards, when at a certain distance they are bent upon themselves, 

 and then are directed outwards and backwards. At the point of 

 Hexion there appears to be some sort of a simple joint present. 



The jiosterior cornua are represented by paired bony rods of a 



