200 DIVISION I. VERTEBRAL ANIMALS.—CLASS IV. PISCES 
always remains uppermost when the animal is swimming, while all other 
fishes swim on the belly. The upper side is, in general, deeply colored, 
while the other side is whitish. The body, from the head backwards, though 
formed nearly as usual, partakes a little of this peculiarity. The two sides 
of the mouth are not equal, and the pectoral fins are rarely so; the body is 
depressed, and elevated in the direction of the spinous processes ; the dorsal 
extends along the whole back; the anal occupies the lower edge of the body, 
and the ventrals are sometimes united with it. The fins are thus lateral 
fins, in respect of the swimming of the fish when in motion; and the action 
of the spine is vertical, in respect of that position, and not lateral, as in 
other fishes. They have six gill-rays; the abdominal cavity is small, but 
extends in a cavity embedded in the flesh on the two sides of the tail, for 
the purpose of containing some of the viscera; they have no air-bladder, 
and they seldom rise far from the bottom. Notwithstanding the peculiarity 
of the cranium, by that twist of the neck which brings both eyes to one 
side, the bones are the same as in other families, but very differently pro- 
portioned. They are found along the shores of almost all countries, and 
are, generally speaking, wholesome and agreeable eating. 
“Some individuals have the eyes placed in the opposite side to that in 
which they are generally found in their species, and these are said to be re- 
versed. Others have both sides colored alike, in which case they are called 
‘Doubles.’ It is usually the colored side which is doubled, though occa- 
sionally it is the white one.” 
P. Platessa. —The Plaice. These fishes have a row of sharp teeth in 
each jaw, and very often pavement teeth in the pharynx; the dorsal does 
not advance more forwards than the upper eye, and both it and the anal 
terminate and leave smooth spaces before the base of the caudal; they gen- 
erally have two or three small cceca, and six gill-rays. DP. vulgaris (com- 
mon Plaice) has six or seven tubercles, forming a line between the eyes, and 
spots of aurora red over the brown on the upper side of the body. The 
height is but a third of the length; and the flesh is soft, and soon decom- 
poses. P. jflesus, the Flounder, similar, but with the spots lighter ; some 
tubercles on the head, and some on the base of the dorsal and anal fins, and 
have rough scales on the lateral line. They ascend a considerable way up 
rivers, and reversed individuals are not unfrequently caught. 2. Uimanda, 
the Dab, has the eyes large, the lateral line curved above the pectoral, the 
scales rough, and the upper side brown, with whitish spots. 2. md¢croceph- 
alus, the Laminder, with the eyes smaller, nearer each other, and the back 
finely mottled with brown and yellow. Both these are found in the salt 
water, as is also P. leménoides, the Long or Rough Dab, which has the 
body elongated, something like a saw, and it approaches that species in 
