tu 
FLAT-FISHES 47 
a mirror at the bottom the 
under-surface was found in 
many cases to be very largely 
coloured. But the colour of 
the upper surface is by no 
means constant. On the con- 
trary, the flat-fish appears to 
possess the power, in common 
with all other fishes, of chang- 
ing its colour so as to harmon- 
ise with the tone of its sur- 
roundings. Thus on a light 
sandy ground the exposed 
surface of the body becomes 
pale, while on a dark muddy 
bottom it is almost black. 
By this power of changing 
the colour of the exposed : : 
portion of the body so as to Photo by HW’, Saville-Kent, F.Z.S.] LMiferaren* Sea 
harmonise with the surround- BRILL 
ings, the fish is enabled to Tew 
: A As in the turbot, the eyes are on the left side of the head, instead of on the right side, as in the 
become in a large measure : ‘Vakibus 
invisible, and in proportion 
to the effectiveness of the change to escape its enemies. Some soles are quite invisible. 
The most important of the flat-fishes are the PLAICE, FLOUNDER, Dab, HALIBUT, SOLE, 
TURBOT, and BRILL. 
The PLAICE is one of the commonest of the British flat-fishes, and may be distinguished 
by the numerous orange or red spots which are scattered over the upper surface of the body. 
From 15 to 18 inches in length, specimens are occasionally captured which have attained a 
length of 28 inches. Plaice feed on shell-fish, such as mussels or scallops, which they crush 
by means of strong, blunt teeth in the throat; but worms are also eaten. 
The eggs of the plaice are amongst the largest fish-eggs known. 
The FLOUNDER is a smaller fish than the plaice, and lacks the red spots. It differs from 
the other flat-fishes in the preference it shows for the mouths of rivers, ascending these, 
indeed, so far as to enter fresh-water. 
The HALIbuT is the largest of the flat-fishes, specimens of as much as 20 feet in length being 
on record, while examples of from 6 to 7 feet long are not uncommon in Grimsby market. 
This fish has a wide distribution, occurring on both sides of the North Atlantic and North 
Pacific, being most abundant in deep water. The halibut which are brought into the markets 
of Grimsby and Hull are chiefly caught off the coasts of Iceland and the Farées with 
long lines. 
The SOLE is a shallow-water fish, feeding chiefly upon worms, crabs, and shrimps. These 
it apparently hunts by smell, gliding over the sea-bottom, and tapping with the lower side 
of its head, which is provided with sensitive organs of touch in the shape of filaments. By day 
it conceals itself by burrowing in the sand, coming out after dark to feed. 
The TURBOT resembles the brill, from which it may be distinguished by the greater breadth 
of the body in proportion to the length, the absence of scales, and the presence of large bony 
tubercles scattered over the surface. In Great Britain the turbot is most abundant in the 
English Channel. 
The BRILL closely resembles the turbot not only in general form, but in the numerical 
superiority of the females, and in the habits of the young, which, like the turbot, are surface- 
feeders and possess an air-bladder. 
