The Apodes, or Eel-like Fishes 367 
cephalt, pass through a band-shaped or leptocephalous stage, 
as is the case with Albula and other Isospondyli. In the con- 
tinued growth the body becomes firmer, and at the same time 
Fig. 271.—Larva of Common Eel, Anguilla chrisypa (Rafinesque), called Lepto- 
cephalus grassti. (After Eigenmann.) 
much shorter and thicker, gradually assuming the normal form 
of the species in question. 
In a’ recent paper Dr. Carl H. Eigenmann has very fully 
reviewed the life-history of the eel. The common species live 
in fresh waters, migrating to the sea in the winter. They 
deposit in deep water minute eggs that float at the surface. 
The next year they develop into the band-shaped larva. The 
young eels enter the streams two years after their parents drop 
down to the sea. It is doubtful whether eels breed in fresh 
water. The male eel is much smaller than the female. 
The eel is an excellent food-fish, the flesh being tender and 
oily, of agreeable flavor, better than that of any of its rela- 
tives. Eels often reach a large size, old individuals of five or 
six feet in length being sometimes taken. 
Species of Eels.—The different species are very closely related. 
Not inore than four or five of them are sharply defined, and 
these mostly in the South Seas and in the East Indies. The 
three abundant species of the north temperate zone, Anguilla 
anguilla of Europe, Anguilla chrisypa of the eastern United States, 
and Anguilla japonica of Japan, are scarcely distinguishable. In 
color, size, form, and value as food they are all alike. 
Fossil species referred to the Anguillide are known from 
the early Tertiary. Anguilla leptoptera occurs in the Eocene 
of Monte Bolea, and Anguilla elegans in the Miocene of (Eningen 
in Baden. Other fossil eels seem to belong to the Nettasto- 
mide and Myride. 
Pug-nosed Eels.—Allied to the true eel is the pug-nosed eel, 
Simenchelys parasiticus, constituting the family of Szmen- 
chelytde. This species is scaled like a true eel, has a short, 
