Natural History of British Zoophytes. 319 



appearance it closely resembles C. semidecandrvm, but is at once 

 distinguished by its very slightly membranous bracteae and reflex- 

 ed fruit. It is probably C. semidecandrum of Loiseleur, Fl. Gall. i. 

 323. 



IV. — The Natural History of British Zoophytes. By George 

 Johnston, M. D., Fellow of the Royal College of Surgeons of 

 Edinburgh. (Continued from Vol. i. p. 447.) 



Class— ZOOPHYTA, Solancler. 



(Polypes, Olivier. — Polypi, Lamarck. — Z. polypifera, Grant.} 

 Order I. Hydroida. 



Character. — Polypes compound, rarely single and naked, the 

 mouth encircled with roughish filiform tentacula ; stomach without 

 proper parietes ; intestine ; anus ; reproductive gemmules pul- 

 lulating from the body and naked, or contained in external vesicles. 

 Polypidoms horny, fistular, more or less phytoidal,fixed, exter- 

 nal. 



" As for your pretty little seed-cups or vases, they are a sweet 

 confirmation of the pleasure Nature seems to take in superadding an 

 elegance of form to most of her works, wherever you find them. How 

 poor and bungling are all the imitations of art I When I have the 

 pleasure of seeing you next, we will sit down, nay kneel down if you 

 will, and admire these things."* Thus did Hogarth — our great mo- 

 ral painter — write to Ellis in evident reference to the zoophytes of 

 the present order ; and he must indeed be more than ordinarily dull 

 and insensate who can examine them without catching some of the 

 enthusiasm of the artist. They excell all other zoophytical produc- 

 tions in delicacy and the graceful arrangement of their forms, some 

 borrowing the character of the prettiest marine plants, others assum- 

 ing the semblance of the ostrich-plume, while the variety and ele- 

 gance exhibited in the figures and sculpture of their miniature cups 

 and chalices is only limited by the number of their species. 



The Hydroida vary from a few lines to upwards of a foot in height. 

 They are all, with the exception of the hydra or fresh-water polype, 

 marine productions, and are found attached to rocks, shells, sea-weed, 

 other corallines, and to various shell-fish. Many of them appear to 

 be indiscriminate in their choice of the object, but others again make 

 a decided preference. Thus Thuiaria thuja prefers the valves of old 

 shells, Thoa helecina is more partial to the lai'ger univalves, Antennu- 



* Lin. Corresp. Vol. ii. p. 44. 



