156 ALUS. [Vol. XVIII. 



anterior cartilaginous remnant of the arch, and articulates with 

 the cartilage that caps the ventro-lateral, or septo-maxillary, proc- 

 ess of the ethmoid. The anterior edge of the facet always pro- 

 jects upward as a short process, and gives insertion to part of the 

 articular fibrous tissue that binds the palatine to the skull. 



Along the ventral edge of the palatine there is a tall, tlat, thin 

 ridge, or fin of bone, the ventral edge of which is lined with small 

 sharp teeth. This fin of bone occupies about the middle three 

 fifths of the length of the palatine, is tallest at or near its anterior 

 end and from there diminishes gradually in length until it dis- 

 appears, at its posterior end, in the general level of the ventral 

 surface of the bone. 



The large middle cartilaginous remnant of the palato-quadrate 

 arch is a flat block of cartilage with a straight, transverse, anterior 

 end, and a shelving posterior end. The dorsal edge of the latter 

 end rises as a flat, transverse, pointed process, which is directed 

 upward, forward and laterally. It forms the hind edge of a large 

 but shallow transverse articular surface, which is held up against 

 the ventral edge of the postero-ventral arm of the preorbital ossi- 

 fication by a strong ligament that has its insertion on the cartilagin- 

 ous process. This ligament arises from the posterior surface of the 

 preorbital ossification, and allows a swinging and sliding, latero- 

 mesial motion of the palato-quadrate. The fact that this strong 

 ligament has its insertion on a cartilaginous process, and not on 

 bone, should be noted as indicating that the ossifications of the 

 palato-quadrate have probably not been developed in any relation 

 to the attachments of muscles or ligaments. 



The Mandible (Figs. 4 and 35) consists of three ossifications, 

 the articular, angular and dentary, and a cylindrical rod of carti- 

 lage representing Meckel's cartilage. 



The Articular (ART) has a broad, straight portion, convex 

 externally and concave internally. From the hind end of this 

 portion two large processes arise, one projecting dorso-anteriorly 

 and the other ventro-anteriorly, giving to the whole bone a dart- 

 like appearance. Into the angle between the ventral process and 

 the body of the bone the hind end of the ventral arm of the dentary 

 fits, a space usually being left between the ventro-posterior end 

 of the dentary and the adjoining edge of the articular. The ven- 



