SkuU of Gouoihywchns Greyi. 365 



between the ethmoid region of the craninra and the maxilla, 

 nor between the ethmoid and the premaxilla. Neither 

 maxilla nor premaxilla bears teeth; there is no surmaxilla. 



The mandil)nlar ramns (PI. XVI. figs. 1 and 5) is of remark- 

 able shape, since the articular and dentary components o£ the 

 coronoid ])rocess are widely separated, the deutary component 

 standing high and being situated near the anterior end of 

 the jaw. The lower margin of the gape is nearly at right 

 angles to the long axis of the mandibular ramus. The 

 dentary is but slightly larger than the articular and bears no 

 teeth. * The angular is distinct from the articular, and there 

 is a sesamoid articular lying on the buccal side of the 

 articular (fig. 1, sar). 



The hyomandibular articulates with the cranium by two 

 barely separated heads, the anterior one small and the poste- 

 rior one broad. The diminution in the size of the mouth 

 appears not to have affected the hyomandibular, the main 

 axis of which is about vertical (figs. 1 and 5, hin) : the sym- 

 plectic, however, is sharply bent forward. The metapterygoid 

 is reduced to a thin rod of bone which runs from the lower 

 end of the hyomandibular to the hind end of the ento- 

 pterygoid. 



The entopterygoid bears at its posterior end a circular 

 patch of stout bluntly conical teeth, reminding one of those 

 of Osteoglossum ; but although the entopterygoid steadies 

 itself against the side of the parasphenoid, there is no definite 

 articulation with that bone such as occurs in Osteoglossum. 

 The ectopterygoid is straight and does not run down the 

 anterior edge of the quadrate. The hyopalatine arch is very 

 thin at the junction of the palatine with the entopterygoid 

 and ectopterygoid, and there is a ligamentous attachment 

 here with the prefrontal. The palatine is curiously inflated 

 and comes close to the surface of the head in front of the 

 preorbital bone in such a manner as to simulate one of the 

 cheek-plates. The bulk of the palatine lies in advance of 

 the dentary symphysis (figs. 1 and 5, pi). 



The lower or liorizontal part of the preopercular is larger 

 than the upper or vertical part (fig. 5, pop). There are four 

 branehiostegal rays, the two posterior ones considerably 

 larger and flatter than the other two. They are all attached 

 to the outer face of the epihyal. 



The lower hypohyal is larger than the upper. The urohyal 

 is moderately small, and is broadened out in front into a 

 horizontal plate. The glossohyal is narrow and tipped by a 

 hemispherical cartilage (text-fig., ffh). The first basi- 

 branchial is cartilaginous ; the second is large and bears on 



