452 DR. W. G. RIDEWOOD ON THE CRANIAL [DeC. 13, 



and in an external view is barely visible between the quadrate 

 and the preopercular. This concealment of the symplectic is 

 titilised as a family character by Boulenger (Ann, Mag. Nat. 

 Hist. (7) xiii. 1904, p. 164). The palatine is short and com- 

 pletely ossified, and has two distinct articular heads, one for the 

 mesethmoid and vomer, and one for the prefrontal ; its ventro- 

 external surface enters into extensive synovial articulation with 

 the maxilla. There are four or five minute teeth on the palatine, 

 but none on the pterygoid bones. 



a 



pop mpi ^y ^^ 



Cliirocentrus dorab, hyopalatine avcli, opercular bones, and mandible, left side, 

 mesial aspect. For explanation of lettering see p. 493. 



OjJercular Series (text-figs. 119 and 120). — The opercular bone 

 is of normal proportions ; the subopei'cular is of small vertical 

 extent, and has at its anterior end a strongly developed process 

 rising against the anterior edge of the opercular. The branchio- 

 stegal rays are eight in number. The front four are shaped like 

 the blade of a scythe, and there is a fairly regular transition in a 

 backward direction to the larger and lamellate posterior members 

 of the series. The first five are attached to the outer surface of 

 the ceratohyal, and the other three to the outer surface of the 

 epihyal. 



Hyohranchial Seines (text-fig. 121, p. 453). — The interhyal is 

 ossified. The upper hypohyal is considerably smaller than the loAvei-. 

 The glossohyal is small and bears a few minute teeth on its supero- 

 lateral edges. The first basibranchial is short, the second and 

 third are exceptionally long. A long dentigerous plate overlaps 

 the three basibranchial bones, and a similar plate, of large size, 

 but readily removable, and not shown in the figure, overlies the 

 common cartilage of the fourth and fifth basibranchials. The 

 dorsal parts of the branchial skeleton appear short in proportion 

 to the ventral, but the disparity is j)robably to be accounted for 



