210 DESCRIPTIOX OF A SPECIMEN 



point. The siqoerior surface is convex both longitudinally and laterally. It is bounded 

 behind by a curved ridge, concave backward, which connects the nasal and zygomatic pro- 

 cesses, and which overhangs the anterior internal angle of the orbital plate. The nasal 

 process is the continuation of the internal part of this surface. It begins so gradually that 

 the length cannot be given ; at its posterior end it is 5 inches broad. Below its smooth 

 upper surface it consists of a number of very delicate plates to articulate with others from 

 the frontal. The zygomatic process is directed outward, downward and backward. The 

 outer border runs in a straight line to the tip, but the internal is concave towards its poste- 

 rior end, so as to increase the breadth of the nasal opening. This upper surface is marked by 

 seven foramina on the left bone, and twelve on the right ; the latter, however, are smaller. 

 They present no regularity except in opening forward and outward, and in being confined 

 to less than the posterior half of the bone. 



The internal surface is nearly at right angles with the superior, and is also triangular. 

 Posteriorly it runs into the nasal process ; below and in front of which it forms part of the 

 wall of the nasal cavity, in which it begins to bear a prominent longitudinal ridge which 

 overlaps the lateral plate of the vomer, and is soon included between that and the inter- 

 maxillary. The lower part of the posterior border shows a curve corresponding to the an- 

 terior convexity of the palate bone. The inferior surface may be said to be concave in all 

 directions; it is marked by some twenty- four foramina and grooves; though very irregu- 

 lar these may be divided into two classes, the first consists chiefly of grooves running 

 forward along the median or vertical part of this surface, the second forms part of a circle 

 of foramina, pointing towards the periphery of the bone. They are in places arranged in a 

 double row, one opening just internal to the other. The internal posterior angle is free, 

 hanging under the orbital plate of the frontal, and a little external to the palatal ; the pos- 

 terior edge is irregular in outline ; just before reaching the outer angle it presents a small 

 concavity with which the jugal articulates very accurately. The concave hase, quite hidden 

 when the bone is in place, does not require a minute description, its chief peculiarity con- 

 sists in the large foramina communicating for the most part with one another, by w'hich 

 the canals begin which convey the nerves and vessels to the various openings already 

 mentioned. 



The Intermaxillary (PL vi, fig. 1 h, fig. 2^). — Greatest length 8 feet 11 inches, with 

 about one inch to restore. For about the anterior three-fourths of its length it presents 

 three surfaces and three borders. The superior is smooth and of denser structure than the 

 others ; it forms a continuous surface with the superior maxillary; the external surface is 

 in apposition with that bone and is in no way peculiar. The internal and inferior is con- 

 cave. At about two-thirds of the length of the bone from before, the edges cease to be 

 sharply defined, and the bone becomes thin and twisted upon itself in such a manner that 

 the superior surface becomes the internal, forming the outer wall of the nasal cavity. At 

 its extremity the bone ends in a few vertical scaly plates, which interdigitate with others 

 from the frontal. 



TJie Nasal (PI. vi, fig. 1 I). — This is a wedge-shaped bone with a concave base and a 

 blunted edge. The thin end which is directed backwards is rough to articulate with the 

 frontal. The internal surface, which is in apposition with that of the other bone, is smooth, 

 but marked by some curved lines naming downward and forward. The outer surfoce is 

 received into a depression chiefly in the frontal, but in part in the intermaxillary. Its 



