442 E. T. NEWTON" ON A NEW FISH FEOM 



are mostly broken, but are evidently flattened and sharp -edged, like 

 those of the mandible, which they almost equal in size. 



The bone marked ju is probably a jugal ; it may perhaps be one 

 of the suborbital series ; but if the latter, one would expect to find 

 the centre of ossification towards its upper border, whereas it is 

 evidently towards the lower and hinder margin. 



Prcemaccilla. — The side view of the head (fig. 1) shows the prse- 

 maxilla in a foreshortened aspect ; from above (fig. 2) it is seen to 

 be about twice as long as broad, and of an ovoid form, the oral 

 border being rather wider than the opposite end, which is a little 

 broken. The external surface is convex. The alveolar border has 

 five tooth-sockets ; one of these still retains a perfect tooth : in two of 

 them there are roots only, the crowns having been broken off ; and 

 in two there are young teeth just appearing above the margin. The 

 broken roots are seen to be circular in section; and two or three of the 

 teeth seem to have been a little larger than those in the maxilla. 



Suspensorium and Pterygopalatine Arcade. — The upper part of the 

 hyomandihular (Jim) is widely expanded, and has apparently a very 

 elongated surface for articulation with the skull. The front of this 

 expanded part is attached to the sphenotic ; and its posterior angle 

 is connected with the operculum. The lower part of the hyoman- 

 dihular is only seen upon the outer surface as a long pointed style, 

 lying between the upper part of the prgeoperculum and the meta- 

 pterygoid. The bone marked sym, which is wedged into the back 

 of the quadrate, is without doubt the symplectic ; its upper part is 

 covered with pyrites, which prevents its relation to the hyomandibular 

 from being seen. 



The quadrate (qu) bone is a large fan-shaped expansion. Its an- 

 terior border and most of the articular condyle are hidden by the ex- 

 tremity of the maxilla and jugal bone. The border which articulates 

 with the preeoperculum is thickened ; and its hinder part is notched to 

 receive the symplectic element. The third or hinder border is thin, 

 and articulates with the metapterygoid, the junction forming a 

 regular slightly curved line. The upper angle, which is broken, 

 overlaps the entopterygoid (mesopterygoid of Parker). 



The metapterygoid (fig. 1, mt.pt) is a triangular bone, having the 

 lower border in close relation with the quadrate, and its hinder edge 

 articulated with the hyomandibular and symplectic. The front part 

 being broken, its extent in this direction cannot now be known ; 

 above and in front it overlaps the mesopterygoid, and sends inwards 

 a horizontal lamina, which forms part of the lower boundary of the 

 orbit. 



The mesopterygoid (fig. 1, ms.pt) is in place ; and its outer surface 

 is seen to have been somewhat semicircular in outline, although now 

 partly hidden by the matrix and surrounding bones. The upper 

 margin is slightly concave, and sends inwards a broad horizontal 

 lamina, which, with the similar plate of the metapterygoid, forms 

 the floor of the orbit. 



The palatine and pterygoid bones are not visible ; but the mass of 



