Suborder Heterosomata 



495 



The Soles : Soleidae. -The soles (Soleidcz) are degraded flounders, 

 the typical forms bearing a close relation to the plaice tribe, 

 from which they may be derived. There are three very differ- 

 ent groups or tribes of soles, and some writers have thought 

 that these are independently derived from different groups of 

 flounders. This fact has been urged as an argument against 

 the recognition of the Soleida as a family separate from the 

 flounders. If clearly proved, the soles should either be joined 

 with the flounders in one family or else they should be divided 

 into two or three, according to their supposed origin. 



The soles as a whole differ from the flounders in having the 

 bones of the head obscurely outlined, their edges covered by 

 scales. The gill-openings are much reduced, the eyes small 

 and close together, the ventral fins often much reduced, and 

 sometimes the pectoral or caudal also. The mouth is very 

 small, much twisted, and with few teeth. 



The species of sole, about 150 in number, abound on sandy 



FIG. 440. Starry Flounder, Platichthys stellatus (Pallas). Alaska. 



bottoms in the warm seas along the continents, very few being 

 found about the Oceanic Islands. The three subfamilies, or 

 tribes, may be designated as broad soles, true soles, and tongue- 

 fishes. 



The Broad Soles: Achirinae. The American soles (Achirina), 

 or broad soles, resemble the smaller members of the turbot tribe 



