A guide to the shell and starfish galleries

by British Museum . Department of Zoology; F. J. Bell; R. Kirkpatrick; E. A. Smith

The texture and consistency may be gelatinous, cartilaginous, horny and flexible, or stony.

The great majority of species are marine, but a considerable number inhabit fresh water. The Polyzoa are classified as follows:—

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Sub-order 1.—Chilostomata.

Cases A and B 1.

The Chilostomata, which contain many more species than all the other groups put together, are divided into three sections:—A. Cellularina, in which the cells are more or less boat-shaped or cornucopia-shaped, and joined together to form flexible branching colonies; B. Flustrina, in which the cells are typically shaped like oblong boxes with membranous front walls; and C. Escharina, in which the whole front wall is calcified.

Case A 1.

Fig. 6.
A, Bugula turbinata, natural size, B, portion × 50.
a, avicularia; m, mouth; o, ovicell.
[‘The Cambridge Natural History.’]