THE BLIND-FISH 
275 
The skeleton of the Leptocephalidse, or Glass Eels as they are termed, from their Eel-like 
shape and singular translncency, is very imperfect, merely consisting of cartilage, and so 
slight that even in the head, where the greatest strength is required, the brain can be seen 
through the translucent skull in which it lies. Their bodies are always extremely compressed 
and mostly leaf -like, so transparent that when lying in a vessel containing water they would 
hardly be noticed, and the lateral line is formed by the intersection of the muscles. 
The Pig-nosed Glass Eel may be known by the lengthened form of its head and snout, 
which are far longer in proportion to the dimensions of the fish than in any other member of 
the family. The generic term Hyoprorus literally signifies swine-beaked, and in former days 
was applied to a certain kind of galley which had a long and slightly turned-up beak. The 
sudden height of the body just behind the head is very remarkable, and on close examination, 
a row of mucous pores will be found along the jaws and on the head. The eyes are not very 
large, and the general length of the species is between four and five inches. As its specific 
name imports, it has been taken at Messina. 
The Hair-tailed Glass Eel is much longer in proportion than the last-mentioned 
species, and its body is so extremely compressed that it is hardly thicker than the paper 
on which this account is printed. This species is also found at Messina. The jaws are slioit 
and round, the eye rather small, and the tail tapers away to a hair-like point. The length 
of this fish is rather more than a foot, and a row of minute points runs along each edge of the 
body. 
The typical genus Leptocephalus is a rather large one, containing more species than the 
four preceding genera together. 
The Hound-headed Glass Eel derives its specific name of Tsenia, or tape-worm, on 
account of its resemblance to that unpleasant internal parasite. Its head is, as its name 
denotes, short and much rounded, and the eyes are globular, projecting, and extremely 
large. The jaws are tolerably well furnished with small teeth. In shape it is long and 
rather rounded, and the absence of fins renders its resemblance to a tape- worm extremely 
striking. It seems to be an Asiatic species, having been captured in India and the neighboring 
islands. 
In the Anglesey Morris ( Leptocephalus morrisi), another example of this genus, the 
head is blunt, the eye moderate, the body much compressed, and deepest at the latter third of 
its length. When living, its polished surface reflects gleams of iridescent light as it winds its 
graceful way through the sea weeds among which it loves to sojourn, like a ribbon of animated 
nacre. But when dead and placed in spirits, all the delicate opalescence of its body fades, and 
soon deteriorates into an opaque dull whiteness like wet parchment. 
THE BLIND-FISH. 
The reader will remember that on several occasions it has been deemed expedient to give 
examples of remarkable deviations from the ordinary system, and to call attention to the 
wonderful economy of nature, which is most averse to wastefulness, and declines to expend its 
powers on organs that if existing would be in abeyance. A recent example of such modifica- 
tion has been given in the proteus, on page 186, that curious reptile, or semi-reptile, which 
inhabits caves wherein penetrates no ray of light, and which, having no need of external eyes, 
is altogether devoid of such useless organs. 
The Blind-fish of America affords another instance of similar economy in structure. 
Living, like the proteus, in a subterranean and perfectly dark grotto, it needs no eyes, and 
in consequence possesses none, their place being merely indicated by two minute black dots 
on the sides of the head. The head is naked, but the body is covered with scales and the jaws 
are furnished with some small but sharp teeth. Its color is whitish-gray, as is, indeed, mostly 
the case with animals that have been long deprived of the color- giving sunlight. The grotto 
which contains this very remarkable little fish is in Kentucky. 
Of the Blind -fishes, family Amblyopsidce , living in caves, three genera are now known. 
