Identifier: introductiontozo00dave Title: Introduction to zoology; a guide to the study of animals, for the use of secondary schools; Year: 1900 (1900s) Authors: Davenport, Charles Benedict, 1866-1944 Davenport, Gertrude Anna Crotty, 1866- Subjects: Zoology Publisher: New York, Macmillan company London, Macmillian and co., ltd. Contributing Library: MBLWHOI Library Digitizing Sponsor: MBLWHOI Library

View Book Page: Book Viewer About This Book: Catalog Entry View All Images: All Images From Book

Click here to view book online to see this illustration in context in a browseable online version of this book.

Stylactis, a tubularian rocks beneath seaweed, and hydroid

Text Appearing Before Image: ze,single individuals of Tubularia becoming six inches long.Other species grow 011 gastropod shells which are occu-pied by hermit-crabs (Figs. 194 and 195). So thickly dothey grow that they make a plush-like covering on theupper part of the shell, and they have the curious habit 1 Small Hydra. 2 Combining the qualities of Hydra and the corals. 3 From tubulus, a little tube. THE HYDRA AND TTN ALLIES 209 of building out the lip of the shell so as to enlarge theaperture. They do this in order that the hermit-crab, asit grows larger, shall not beforced to exchange the shellfor a larger one, leaving thehydroids on the cast-off shellto roll about on the beachand perish. Of the Campanularidae,1 orbell-hydroids, one of thecommon representatives isObelia,2 which may be foundat low tide hanging from -i i ,1 11 FIG. 1!H.—Stylactis, a tubularian rocks beneath seaweed, and hydroid> gl.0^ugou asn:iiL Nat. looking like delicate white size. Photo, of living animal by threads (Fig. 196). Observed

Text Appearing After Image: '

Note About Images