Among the flatfishes the plaice is like the halibut and unlike the 
flounder and its relatives in having a very large mouth with well 
developed teeth, the mouth indeed being so large that its angle is 
well back to the middle of the eye. Unlike the halibut it has along 
the middle of the body an almost straight ‘lateral’ line, which is 
without any arch near the head, and it differs from both the halibut 
and turbot in having the end of the tail rounded instead of concave 
or hollow. Finally the plaice differs from the window-pane, which 
also has a rounded tail and a large mouth, in having the eyes on 
the right side of the body instead of on the left side, and in not 
having a distinct arch in the ‘lateral’ line near the head. It alone 
of our flatfishes has these three characters combined—large mouth, 
almost straight lateral line, and rounded tail (see figure 2). The 
Nearly straight 
lateral line 
Rounded tail iit bh ; Large mouth 
Fic. 2.—Plaice fifteen inches long from Le Have bank, off Nova Scotia. After H. L. Todd. 
colour of the plaice is a uniform light or dark reddish-brown, 
although there is a series of from three.to five dark spots along 
each side of the body. These are, however, usually distinct only 
in the young (see figure 1), but occasionally they are to be seen in 
quite large and old fish. Another character that is familiar to any 
one that handles the fish is the very distinct roughness of the sur- 
face, which is caused by the small, but sharp teeth on the free edge 
of each scale (see figure 11). 
