CLASS ANNULATA.
We cannot better describe the Annulose animals than in the words of Lamarck; he calls them,
“Animals with soft bodies, lengthened, worm-shaped, naked, or inhabiting tubes, with the body divided into segments, or at least transverse wrinkles, often without head, without eyes, and without antennæ, unfurnished with articulated limbs, but the greater number having, instead, small protuberances, bearing spines, and capable of being retracted at pleasure, disposed in rows along the sides, though not continued quite to the extremity of the body, and assuming various forms. They have also red blood circulating by veins and arteries; this separates them from the Worms, properly so called, which have white blood. This colour of the blood is a singular fact, since the animals are much less complex in their organization than the Mollusca, which have colourless blood. The Class of Annulose animals has been separated into three Orders, namely, Annulata sedentaria, which are fixed to other substances; Annulata antennata, possessing antennæ, or feelers; and Annulata apoda, without projecting members answering as feet, serving solely to attach the animal to rocks, stones, &c.”
Shells of various sedentary Annulose Animals.
ORDER ANNULATA SEDENTARIA,
(Sedentary Annulose Animals.)
The creatures which form this order are generally found attached to rocks, shells, &c. and are usually of small size. The engraving represents a variety of species of these animals. Of the genus Serpula there are many species, but as it is in general merely the shell that is found in collections, they are but ill defined; some of the species are found in almost all climates. The animal of the Serpula has great power of contracting its body, but it never leaves its shell or tube; this tube is gradually lengthened by the inhabitant, who always occupies the most recently-formed portion of it; its operculum, the lid with which it closes the opening of its tube, is very prettily formed; it is something like the mouth-piece of a trumpet, but of course not perforated, and it closes the opening with great accuracy.