24 PROCEEDINGS OF THE NATIONAL MUSEUM vol. hm 



dibular branch being posterior and more or less internal to the 

 hyomandibular bone (fig. 4: ho). After exiting from the skull, the 

 hyomandibular branch enters the medial face of the hyomandibular 

 bone and passes downward within it. In the gadoids (Stannius, 1849, 

 p. 33), the hyomandibular branch has the same cranial exit as the 

 main facialis trunk, after which it swings backward and penetrates 

 the front of the hyomandibular bone. 



Branchiostegal rays. — The ophidioids are said to have six to 

 eight branchiostegal rays (Kegan, 1912d, p. 277); in Gadopsis there 

 are seven. This is a rather high number for percoid derivatives. In 

 the stichaeoid blennies (Makushok, 1958, p. 21), these are rarely 

 seven, generally fewer. 



Pelvic fins and pelvic girdle. — The filamentous fins and their 

 presumed function in Gadopsis, the ophidiids, brotulids, and certain 

 gadids already have been discussed. (Zoarcids never have filamentous 

 pelvics.) Despite the general similarity between the pelvic fins of the 

 Ophidioidei and certain of the Gadiformes, there are minor differences, 

 some of which suggest different ancestries for the two groups. Thus, 

 even when, as in the gadoid Laemonema, the pelvics become reduced 

 to two main filamentous rays, there are rudimentary rays medial to 

 these; in the ophidioids, when there is a rudimentary structure in 

 addition to the filaments, it is a small ossicle lateral to the main rays 

 and presumably represents a reduced spine (as in the Blenniidae and 

 Zoarcidae) . At the other extreme, however, the maximum number of 

 soft pelvic rays in gadoids is twelve, but the ophidioids never have 

 more than two. The pelvic fins of the Gadiformes, when present, are 

 wide set and articulate with pelvic bones that are never attached 

 directly to the cleithra; the pelvic fins of ophidioids, when present, are 

 close set and articulate with pelvic bones that are usually, though not 

 always (D. M. Cohen, pers. comm.), attached directly to the cleithra. 



Freihofer (1963, p. 141) recently has noted the similarity of the 

 ramus lateralis accessorius pattern in the gadoids, ophidioids, zoarcids, 

 and (in litt.) nototheniids. In all of these, the pelvic branch of the 

 ramus lateralis accessorius extends downward across the base of the 

 pectorals instead of downward along the postcleithrum behind the 

 pectorals and thence forward to the pelvics. But all four groups of 

 fishes mentioned have the pelvics far forward, where the normal 

 percoid nerve course would be highly circuitous. Furthermore, all four 

 are groups living near the bottom, which may or do (Phycis, see above) 

 use their pelvic fins to locate food. That the shorter and presumably 

 more efficient course of the ramus lateralis to the pelvics developed 

 independently in these groups is suggested by the fact that Gadopsis, 

 herein considered to be at the base of the ophidioids, and the Bathy- 

 masteridae, at the base of the zoarcids, have a perfectly normal percoid 



