Fam. 6. Kracken-Snails, Buccinidæ.
Like the preceding family, but their mantle has a groove, and there is a horny operculum. Here belong the Conidæ and Volutidæ, Buccinidæ, Muricidæ, Strombusidæ. Almost all live in the sea and are of sanguisugal habits. They antetypify the Cuttle-fish.
Sixth Class.
Cardiac, Nephritic Animals—Kracken.
3498. Body cylindrical, without sole or foot; frequently venous hearts together with the arteriose hearts, and a kidney-like organ.
Such are the proper Cylindrical Snails, which are either sessile or fixed, or move themselves by fins and what have been called arms—Sessile and Natant Kracken. Here belong the Salpæ, Cirripedia, Brachiopoda, Pteropoda, Heteropoda, and Cephalopoda. They all live in the sea.
Branchiæ and sexual relations very varied.
They divide likewise into two orders, in accordance with the two circles of Mucus-animals and Conchozoa; the former are spathiform, mostly gelatinous, and firmly sessile or fixed; androgynous, without head and rudders or fins. The branchiæ trellis-like and filiform—Ascidiæ, Cirripedia and Brachiopoda.
The others have a kind of head with arms and eyes, or fin-shaped steerage-organs upon the body; branchiæ pectiniform, reticular, and leaf-shaped—Pteropoda, Heteropoda, and Cephalopoda.
Order 1. Protozooid Kracken—Rumpfkracken.