PERCIFORM FISHES — GOSLINE 



45 



fishes are the trichonotid Crystallodytes, notograptids (fig. 8d), con- 

 grogadids, and possibly the zoarceoid Ptilichthys (Makushok, 1958, 

 p. 66, fig. 38b). 



The mesopterygoid is developed variously. In Trachinus, it is 

 broad and in T. draco, it bears teeth. Another family in which, so far 

 as known, it is consistently broad is the Trichonotidae. On the other 

 hand, the mesopterygoid appears to be narrow throughout the 

 zoarceoids. 



Gill arch system. — The gill arch system of the Blennioidei is 

 basically percoid, with the lower pharyngeals always separate. Only 

 two modifications in the Blennioidei will be noted. The first, occurring 

 in the congrogadoid Notograptus, is that the posterior basibranchials 

 have dropped out. The second, which recurs repeatedly, is that the 

 three upper pharyngeal tooth patches become reduced to two or, 

 in blenniids, to one. 



Dorsal portion of the head (fig. 9). — The frontals usually are 

 paired in the Blennioidei; however, in at least the tropical blenny 

 Runula, the frontals of the two sides seem to have fused. 



ns pb po le me a I 



Figure 9. — Diagram of certain structures in Prolatilus jugularis (al = anterior level reached 

 by the body musculature extending over the cranium, le = lateral extrascapular, ns = upper 

 end of neural spine, pb = predorsal bone, po = posterior rim of supraoccipital, pt = pteryg- 

 iophore of first two dorsal spines). 



On the dorsal surface of the cranium posteriorly, the Blennioidei in 

 general differ from the typical percoid in that the body musculature 

 does not extend forward over the skull, and the supraoccipital and 

 frontal-parietal crests, which, in part, form surfaces of attachment 



