Hippoglossus. fishes. MALACOPTERYGIOUS. 199 
107. P. Eyes on the left side ; the left eye subver- 
tical. 
Pleuronectes Cyclops, Don. Brit. Fishes, t. xc.~ At Aberfraw in Angle- 
sea, Captain Merrick. 
Length l|th inches. Body broad, with dusky spots, surrounded by a 
whitish ring, smooth. Middle rays of the dorsal and ventral fins longest. 
Head protruded ; the left eye placed in the middle of the lateral edge. La- 
teral line curved over the pectorals — This is probably the fry of some of the 
preceding species, belonging to a reversed variety. 
Gen. XLIX. HIPPOGLOSSUS. Holibut. — Teeth nu- 
merous, slender, pointed. A spine in front of the anal fin. 
Tail lunated. 
108. H. vulgaris. Common Holibut. — Body lengthened, 
smooth. Lateral line bent over the pectorals. 
Passer Britannicus, Merr. Pin. 187. — Bhombus Isevis, Sihb. Scot. 24. — 
Hippoglossus, Will. Ich. 99 — Pleuronectes Hipp. Linn. Syst. i. 456. 
Penn. Brit. ZooL iii. 226 — Common. 
Upwards of 2 feet in length, and in weight sometimes exceeding 200 pounds. 
Colour above dusky-brown, beneath white ; free from spots. Body tapering 
towards the tail, D. 105, P. 15, V. 6, A. 79, C. 17- — The flesh of this species 
is not held in high estimation. It is generally called Turbot in the Edin- 
burgh market. 
Gen. L. ANGUILLA. Eel. — Gill-opening under the pec- 
torals. Anal, dorsal, and caudal fins continuous. 
w 109. A. vulgaris. Common Eel. — Colour of the dorsal and 
anal fins uniform. 
A. Merr. Pin. 189, Sibb. Scot. 25, Will. Ich, 109, — Mursena unicolor, 
maxilla inferiore longiore. Art. Ich, Syn, 39,— Mursena Anguilla, Linn. 
Syst, i, 426. Penn. Brit. ZooL iii. 142.— Common in rivers and estua- 
ries. 
Length from 1 to 3 feet. Colour, above, dark olive-brown, whitish on the 
belly. In the variety called silver eel.^ the belly and sides are silvery and sub- 
translucent. The head is depressed ; the lower jaw longest. Eye imme- 
diately above the gape ; irides reddish. Nostrils with two openings on each 
side ; one a simple pore near the eye, the other a tubular wart on the snout. 
GiU-opening immediately in front of the temporal fin. This species spawns 
in the sea ; for which purpose it leaves the lakes and rivers, descending 
from August to November. It migrates in greatest numbers in dark stormy 
nights. The young ones begin to appear on the shore in March, April, or 
May, and proceed in myriads towards the mouths of rivers for the purpose 
of ascending to the lakes and marshes. In their ascent, where eel fisheries are 
of value, the young are assisted in surmounting obstacles, such as the barrier 
of a mill-dam or a cascade, by straw-ropes, so placed that the young eels can 
twist themselves round, and reach the summit. The migrations of the eel 
were first pointed out with accuracy by Redi (Opus, part iii. p. 99, ed. 1729). 
Some good observations by the Rev. George Mack, are recorded in the Sta- 
tistical Account of Scotland, vol. xvi. p. 388, in reference to the eels of th^ 
Dee, 
