Series Plectognathi 



427 



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 



FIG. 365. Rosefish, Sebastes marinus Linnaeus. 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 3^ gills and no slit behind the last. 



FIG. 366. Skull of Scorpcenichthys 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 



