GELATINOSI. 433 



animals are united in more or less considerable number on a common 

 base, sometimes in the form of a creeping stem*, and sometimes 

 having a broad surface |-. 



LuCERNAUIA, Mull. 



The Luccrnaricie should apparently be approximated to the Actiniae, 

 but their substance is softer; they fix themselves to fuci and other 

 marine bodies by a slender pedicle, and their superior portion dilates 

 like a parasol, in the centre of which is the mouth. Numerous tenta- 

 cula united in bundles are arranged round its edges. Between the 

 mouth and these same edges are eight organs resembling cocca, \)VO- 

 cccding from the stomach and containing a red and granulated sub- 

 stance, In the 



S. quadricorms, Miill., Zool. Dan., XXXIX, 1, 6, the edge is 

 divided into four forked branches, each of which bears two groups 

 of tentacula. In the 



L. auricula. Ibid., CLII, the eight groups are equally distri- 

 buted round an octagonal margin :|:. 



ORDER II. 



GELATINOSI. 



The gelatinous Polypi, unlike the preceding ones, are not invested 

 with a firm envelope, neither is there a ligneous, fleshy, nor corneous 

 axis in the interior of their mass. Their body is gelatinous and more 

 or less conical ; its cavity supplies the want of a stomach. 



Hydra, Lm. 



Of all the animals of this class, these are reduced to the greatest 

 degree of simplicity. A little gelatinous horn, whose edges are pro- 

 vided Avith filaments that act as tentacula, constitutes their whole 

 apparent organization. The microscope discovers nothing in their 

 substance but a diaphanous parenchyma filled with more opaque 

 granules. Nothwithstanding this, they swim, crawl, and even walk 

 by alternately fixing their two extremities in the manner of Leeches 

 or of the caterpillars called Geometrae. They agitate their tentacula 

 and use them for seizing their prey, which can be seen being digested 



* Ilijdra sociata, Gm. ; Ell. and Soil., CoralL, I, i ; Encyc, LXX, 1. 



f Alcyonium mammiUosum, Ell. and Sol., loc. cit., 4 ; — Ale. diijitalum, Id. lb., 6. 



These last form the genus Palythoe of Lamouroux, and lead to the Alcj'oniae. 

 This genus appears to have been characterized from desiccated specimens. Sec the 

 great work on Egypt, Zool., Polyp., pi. ii, f. 1 — 4. 



+ Add Lucer. fusckularis, Fleming., Werner. Soc, II, xviii, 1, 2; — Luc, campa- 

 nula, Lamouroux, Mem, du Mus., II, xvi. The Lucernaria phrygia, Fab.; Faun. 

 Groenl., 345, should, apparently, form another genus. See the Memoir of M. La- 

 mouroux on these Zoophytes, in the Mem. du Mus., II. 



