706 Suborder Heterosomata 
of flounders, having the ventral fin of the eyed side extended 
along the ridge of the abdomen. The eyes and color are, how- 
ever, on the right side. The eyes are separated by a narrow 
interorbital ridge. In most of these forms the body is broad 
and covered with rough scales. The species are mostly less 
than six inches long, and nearly all are confined to the warmer 
parts of America, many of them ascending the rivers. A very 
few (Aseraggodes, Pardachirus) are found in Japan and China. 
Some are scaleless and some have but a single small gill-open- 
ing on the blind side. The principal genus is Achirus. Achirus 
fasciatus, the common American sole, or hog-choker, is abun- 
dant from Boston to Galveston. Achirus lineatus and other 
species are found in the West Indies and on the west coast of 
Mexico. Almost all the species of Achirus are banded with 
black and the pectorals are very small or wanting altogether. 
All these species are practically useless as food from their very 
small size. 
Fia. 609.—Hog-choker Sole, Achirus lineatus (L.). Potomac River. 
The European Soles (Soleinez).—The European soles are more 
elongate in form, with the ventral fins narrow and not extended 
along the ridge of the abdomen. The eyes are on the right side 
with no bony ridge between them. No species of this type is 
