~ 154 — 



bone, and also on the mesial edge of the grooved portion posterior to it, rests the slender pointed 

 liind end of the posterior, process-like portion of the lachrymal. This end of the lachrymal is grooved 

 on its dorso-external surface, and participates in the articulation with the ectethmoid, the articulation 

 thus representing the lachrymo-ethmoid articulation of the other fishes described. The dermo- 

 ectopterygoid, completely ankylosed with the ectopterygoid, thus fulfils the fuuction of the posterior 

 ethmoid process of the palatine of both Scorpaena and Trigla; but nevertheless the bone does not 

 seem to be a palatine element, its relations to the ectopterygoid being much more intimate than 

 those to the palatine. 



The PALATINE is a slender rod of bone with an enlarged and flattened anterior end. The 

 ventral surface of the hind end of the rod-like portion of the bone rests against the dorso-mesial 

 surface of the dermo-ectopterygoid, as just above described. The lateral surface of this end of the 

 palatine, or the lateral surface of the covering dermo-ectopterygoid, and the lateral surface also of the 

 anterior portion of the palatine, rest against the internal surface of the posterior, process-like portion 

 of the lachrymal, the slit-like opening between these two surfaces of contact lodging the lateral portion 

 of the nasal sac. In the angle between the rod-like part of the bone and its enlarged anterior end, 

 on the mesial surface of the bone, there is a concave articular surface, with a slight process at its 

 anterior edge. This articular surface hooks around and articulates with the anterior edge of the 

 little anterior palatine eminence of the ethmoid cartilage. Anterior to this articular surface, the 

 anterior end of the palatine widens, its mesial edge being slightly concave and its anterior edge 

 rounded and capped with cartilage. This part of the palatine forms its maxillary process, and fits 

 in the depression and groove, already described, on the ventral surface of the base of the spatula- 

 like anterior portion of the lachrymal. Between the curved mesial edge of this maxillary process 

 of the bone and the lateral portion of the anterior edge of the vomer, a semi-oval space is enclosed, 

 through which the ascending process of the maxillary projects from below upward; this process of 

 the maxillary articulating by one surface with the vomer and by the other with the palatine, and 

 being bound to both bones by connective tissue. 



The OPERCULAR has the irregulär shape shown in the figures. On the inner surface of the 

 anterior edge of the bone there is a deep depression which receives the opercular articular process 

 of the hyomandibular. Dorso-posterior to this depression there is a larger depression on the inner 

 surface of a dorsal, process-like portion of the bone, this depression giving Insertion to the adductor 

 operculi. Dorsal to the surface of Insertion of this latter muscle, in a narrow line along the dorsal 

 edge of the bone, the levator operculi has its Insertion. The dilatator operculi is inserted on the 

 anterior edge of the bone, immediately lateral to the articular facet for the hyomandibular. On the 

 outer surface of the bone there is a horizontal ridge which terminates posteriorly in a spine, this spine 

 being double in one of my specimens. Dorsal to this spine there is, on the hind edge of the bone, 

 a second spine. 



The SUBOPERCULAR is a deUcate bone that lies along the inner surface of the hind edge 

 of the opercular, projecting dorsally beyond the dorsal edge of that bone. 



The INTEROPERCULAR lies along the inner surface of the preopercular, considerably anterior 

 to, and wholly detached from the opercular and subopercular. Its antero-ventral end is slender and 

 rod-like, and almost reaches, and is bound by ligament to, the hind end of the mandible. Its dorso- 

 posterior portion is flat and broad, and lies against and is firmly bound by ligament to the lateral 



