174 Scientific Proceedings, Royal Dublin Society. 



is grooved for the symplectic and anterior process of the hyoman- 

 dibular. The base articulates with the quadrate, and in front it 

 touches the ectopterygoid. 



The ectopterygoid is a splint of bone, somewhat expanded 

 behind, where it articulates with the quadrate. A small strip of 

 cartilage persists between the two bones. In front it articulates 

 with the palate ; above and internally, with the entopterygoid. 

 Its postero-siiperior angle articulates with a small portion of the 

 metapterygoid, the latter overlapping it externally. 



The entopterygoid is a nearly flat, ovate-oblong scale of bone, 

 the broader end being anterior. It lies on a plane internal to the 

 ectopterygoid, to which it articulates by its lower edge. In front 

 it joins the palate. Behind it tapers to a blunt point, which does 

 not quite reach the metapterygoid. From the anterior end above 

 and from the cartilage in front of this, a strong ligament passes to 

 the prefrontal, being attached to a point below the lachrymal arti- 

 culation. ~ 



The palate bone consists of an irregularly quadrilateral plate 

 or body behind, and a sub-cylindrical process in front. The pro- 

 cess does not continue the axis of the body, but bends downwards 

 and slightly outwards. Its anterior end articulates with the upper 

 end of the maxilla, and the lower surface of the lachrymal slides 

 over it above. From its upper border, where it joins the body, a 

 strong ligament connects it to the apex of the anterior superior 

 process of the premaxilla of the opposite side. Just behind and 

 internal to this it is excavated, to articulate with a cartilaginous 

 eminence on the junction of the prefrontal and vomer. It articu- 

 lates behind with the ento- and ecto-pterygoids — with the former 

 above and internally, the line of union being straight, and partly 

 occupied by cartilage; and with the latter below and externally, 

 by a splintery, serrated suture. From the inner side of the ante- 

 rior part of the body a strong ligament is given off to a groove in 

 the side of the anterior end of the vomer. 



In front of the ethmoid is a piece of cartilage which supports 

 the maxilla and premaxilla: it will be spoken of as the pre-eth- 

 moid cartilage for convenience of reference.^ 



^ I have not met witli any name for it in the English text-hooks. Cuvier (Leijona 

 d'Anatomie Comparee, vol. ii., page 652) calls it "un cartilage spherique sur lequel 



