Page:Natural History, Mollusca.djvu/70

From Wikisource
Jump to: navigation, search
This page has been validated.


(Head-footed Mollusks.)

If we were to take a Poulpe or a Cuttle-fish from some hole or tide-pool in the rocks, and look upon its many flexible arms studded with sucking disks, its sack-like body, its green staring eyes, and its bird-like beak, we should be ready to say that such an animal presents but a slight analogy with the sluggish and almost shapeless creatures familiar to us under the name of shell-fish. And, in truth, the former do possess a higher rank in the scale of animal life, having their senses developed into greater perfection, and forming, indeed, the link by which the latter take hold of the races which, from their elaborate organization, are placed at the summit of the scale—the Vertebrata.

We shall better understand the connexion between the present Class and other Mollusca, by considering, with Cuvier, that "the mantle unites beneath the body, and thus forms a muscular sac which envelopes all the viscera. This body, or trunk, is fleshy and soft, varying in form, being either spherical, elliptical, or cylindrical, and the sides of the mantle are in many of the species extended into fleshy fins. The head protrudes from the muscular sac, and is distinct from the body: it is gifted with all the usual senses, and the eyes, in particular, which are either pedunculated or sessile, are large and well developed. The mouth is anterior and terminal,