Series Plectognathi Aaa 
percoid in almost all respects, save in the presence of the sub- 
ocular stay. Their scales are ctenoid and well developed. 
The dorsal spines are numerous and strong. The ventral fins 
are complete and normally attached; the anal has three strong 
Fic. 365.—Rosefish, Sebastes marinus Linneus. Cape Cod. 
spines. The cranium shows only a trace of spiny ridges, and 
the five spines on the preoperculum are not very different from 
those seen in some species of bass. The gill-arches are, however, 
different, there being but 34 gills and no slit behind the last. 
Fic. 366.—Skull of Scorpenichthys marmoratus Girard, showing the suborbital stay (a). 
Otherwise the mouth and pharanx show no unusual characters. 
In the extremes of the group, however, great changes take 
place, the head becomes greatly distorted with ridges and 
grooves, the anal spines’are lost, and the dorsal spines variously 
modified. The scales may be lost or replaced by warts or 
