﻿ix, D.i Day: Ophiocephalus striatus 45 



Ceratobranchials (63). These are concave below and convex 

 above. The condyles or glenoid surfaces of the proximal ends 

 are much larger than those of the distal ends. All are at least 

 slightly concave. Those of the 1st, 2d, and 3d branchial arches 

 articulate with the hypobranchials (24) proximally and distally 

 with the epibranchials (74) of the 1st branchial arch and (64) 

 of the 2d and 3d branchial arches. As there are no hypo- 

 branchials (24) of the 4th branchial arch, the ceratobranchials 

 of this arch articulate proximally with the hypobranchials (24) 

 of the 3d branchial arch, the 4th basibranchial, and the proximal 

 end of the inferior pharyngeals (25). Distally the articulation 

 is with the distal end of the epibranchials (64) of the 4th 

 branchial arch. All of the ceratobranchials are covered, on the 

 convex surface, with detachable patches of cardiform teeth; the 

 same as are spoken of in the descriptions of the hypobranchials 

 (24) and the epibranchials (74) of the 1st branchial arch. 

 The margins of the concavity on the ventral side of each of 

 the ceratobranchials are fringed with branchial lamellae. (Plates 

 XV and XVI.) 



Epibranchials (74) of the first branchial arch. These bones 

 form a part of the accessory branchial apparatus. Each con- 

 sists of a dorsal vertical portion, about two-fifths of the total 

 length, which articulates dorsally with the margin of the flat 

 ventral portion of the pterotic (38), where the pterotic forms 

 a part of the roof of the accessory branchial chamber. Contin- 

 uous with the dorsal spinous portion and at the internal angle 

 of the more ventral lamellar part is a thickening or reinforce- 

 ment which becomes thicker at the ventral end where this epi- 

 branchial articulates with the ceratobranchial (63) of the first 

 branchial arch. The lower portion is lamellar, with a broad 

 internal more ventral part at an angle of about 60 degrees to an 

 external lateral portion, which extends farther dorsally into the 

 accessory branchial chamber. Ventrally the broad edge of the 

 posterior portion and the narrow ventral part of the flange at 

 an angle are continuous with the posterolateral end of the first 

 ceratobranchial (63), helping to form the first branchial arch. 

 The whole ventral margin and, also, the ventral part of the in- 

 terior angle are provided with the detachable patches of cardiform 

 teeth (133), as in the ceratobranchials (63) and the hypobran- 

 chials (24). In Plate VI, fig. 1, the right is seen from the outer 

 side, in Plate XVI both are seen from the inner side, disarticu- 

 lated, and in Plate XV the left is but indistinctly seen. 



Epibranchials (64) of the 2d branchial arch. These artie- 



