654 POLYPI. 



the ovaries are attached in the form of tiuii^led threads. The intervals between the leaflets 

 have communications with the tcntacula; and it should seem that water enters by these, per- 

 vades tlie space between the leaflets, and ultimately escapes by small openings in tlie circum- 

 fereuce of the mouth ; at least, some of the Actinia; eject water in this manner. 



Actinia. 

 These have the body fleshy, often brilliantly coloured ; and the tentacida are arranged in several 

 rows round the mouth, somewhat like the petals of a doable flower, for which reason they have been 



Vlh'' I ■/[''/' called " Sea-anemonies." They are very sensitive to hght, and expand or close 



^..^^^ !■[■[('/'/{ ^{'/^-^ their tcntacula according to the fineness of the day. When the tentacula are 



^^-- V- .-^--.-^r^ retracted, the aperluru from which they proceed closes like tlie month of a purse, 



'^^.Z .■'- '_,:-r and the ani:nal appears a simple fleshy tubercle, adhering to the rock. Their 



/^" "" ''",T,,,; _. -_i— y' reproductive powers are scarcely inferior to tliose of the Hydra. Amputated 



'v-:v/,il7'rl'. lA ^' liarts are speedily re-i)rodiiced ; and tlie numbers niav Ijc niuhjplied hv simplv 

 /'J'm^wV^ 1 .- I ^ . 1.1. 



'' iJ'M di\iding; llie hod}' ; thuugli their u^ual moile of I'cprodnction is l)y bringing forth 



FiE- 142.— A.uiii^. ^ii^ yiiung alivc. These young pass from the ovary into the stomach, make their 

 escape iiy tlie ninutli of ihe parent animal, and find localities for themselves. There are several dis- 

 tinctions among them, besides those of size and colour. All the Actinia; are voracious, and miscel- 

 laneous feeders. Small Fishes, Crustacea, and shelled Mollusca are, however, their usual food, and 

 they very speedily extract the contents, and eject the empty crusts and shells. 



Adhtia proper, lix themselves by a broad and tlat base. There are very many species, especially in ilie ^varme^ 

 seas, where some of them are of large size, and equal in briUiancy of colour to any tlovvers of tlie ji^arden. The 

 species most common in Europe are, among others, A. senilis, which is three inches wide, with a leathery and 

 rug'ged envelope of an orange colour, and two rows of tentacula of moderate leng'th, marked with a ring- of 

 rose-colour. It is found on the sands, into which it sinks if disturbed. A. equini. — Skin soft, finely striated, of a 

 bright purple, often spotted with green ; hody smaller than the last, but the tentacula longer and more numerous. 

 It abounds on the coasts of the Channel, and has a beautiful appearance, xi. pi umoso .—Whxtt, more than four 

 indies wide, mouth in lobes beset with small tentacula, and with a row of larger ones \\ithin the lobes. A. ejj'a'ia. 

 — Light brown with wdjitish streaks, smooth, lengthened, and often thickest at the upper part. Inhabits the Medi- 

 terranean, and usually fixes itself to shells. Those wdiich have been enumerated are a mere specimen out of many 

 species, the distinctions of which are, however, often obscure. 



Thalnssianlha and Discosoma of Ruppel, are Actiniie, the first with branched, and the second with very short 

 tentacula, 



Zoanthus, have tlie same texture, mouth, and tentacula as Actinia, and ilifi'/r little in tlieir general ori.'-anization ; 

 but they occur in groujis adhering to a common base, wiucli is sometimes hruad and flat, and at other times a sort 

 of creeping stem. 



LUCERNARIA, 



Resemljle Actinia, but are of softer substance. They fix themselves by a slender peduncle to sea-weeds 

 and other I)odies. The ujiper part expands like a parasol, and is surrounded by numerous tentacula, 

 arranged in bundles; and between these are eight cojca proceeding from the stomach, and containing 

 a red granulated matter. 



L. quadricorna, has the edge in four forked branches, with two bundles of tentacula in each. L. auricula^ has 

 the border octagonal, with a bundle of tentacula in each division. 



THE SEGOXD OllDER OF THE POLYPI. 



GELATIXOSI. 



These have no firm envelope, and no ligneous, fleshy, or horny axis within the body. Thej' 

 are wholly gelatinous, more or less couieal, .and the simple cavity serves for a stomaeh. 



IIvDKA, 



These are the simplest of all animals in their organization, the "nhole of wliich consists of a sm.all, 

 gelatinous liorn, beset with filaments which serve as tentacula. Even the niicmseope finds notliiug in 

 their bodies but a transparent parenchyma, containing mere opaque granules ; still they can swim and 

 crawl, and even walk, by attaclung the ends of the hody alternately in a manner similar to Leeches and 

 geometrical Caterpillars. They disturb the water with their tentacula, and thus bring their prey within 



