Page:Natural History, Mollusca.djvu/112

 therefore, to pass through a metamorphosis before it attains its permanent condition.

LARVA OF EOLIS.

The eggs in all the species are numerous. They are deposited, during the spring and summer, commonly in the form of a broad ribbon of clear jelly, attached by one of its edges to some solid substance, and generally coiled, or irregularly twisted, or frilled. The eggs themselves are arranged in close-set rows, crossing the gelatinous belt, and giving an opaque white appearance to the mass, which would otherwise be colourless.

In general each egg-shell (chorion) contains but a single yolk, but in some of the Dorides each contains two or three; and in the elegant Antiopa cristata, a specimen of which lately spawned in my possession, I found, upon the average, the extraordinary number of sixty yolks in each egg shortly after deposition. The yolk, which is contained within a delicate, transparent, membranous