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TRANSACTIONS OF THE AMERICAN PHILOSOPHICAL SOCIETY 



Although the skull of ceratioids is highly and diversely specialized, there is a curious 

 constancy in the general features of the opercular, hyoid and branchiostegal series, as far 

 as I could ascertain on stained preparations (Figs. 272-278) of various ceratioids in Doctor 

 Beebe's collection (including especially Cryptosparas, Melanocetus niger, Oneirodes, Lopho- 

 dolus, Lasiognathus, Haplophryne hudsonius). The two heads of the hyomandibular are 

 very pronounced, as is also the pedicle for the opercular; the latter is thin and membranous 

 but is stiffened by a short upper and a long lower bony fork; the opercular stands out laterally 



Lophodolu: 



Fic. 274. Lopkodolus. From stained preparation by Miss Gloria Hollister for Dr. William Beebe. 



and supports the membrane, which continues backward over the excessively long branchio- 

 stegals; these overlap the base of the pectoral fin. The preopercular is curved and very 

 slender; the cerato- and epihyals are usually large and connected with the hyomandibular 

 by a slender, rather short interhyal. The interopercular is a long delicate tracker connected 

 as usual with a ligament fastened to the posterior angle of the mandible. The latter is 

 frequently stout, especially at the posterior end. The palatine usually has a normal 

 process projecting over the maxilla and fused with the reduced lacrymal, — all these features 

 being easily derivable from the Antennarius type as described above. 



Even in antennariids the supraoccipital had already worked its way to the middle of 



