400 



OORNULAEIA.- 



-RADIATA.- 



-Heli.vnthoida. 



the growlli of the mass — such are the Gorcjon'ias. 

 AVhcn the common mass is of a low, rounded shape, the 

 Bpicula in the suhstauce of the skin are strong enough 

 to support the mass^such wo see to be the case in the 

 Alcyonians, or Sea-fingers {Alcyonidce). 



Family— CORNULARIA. 



The family Cormdariidcc, which has a horuj- external 

 skin like that possessed by the genus Tuhularia, is 

 represented in Plate 1, fig. 1, by the pretty species, 

 Cuniularia (rugosa) rosea. 



Family-GOUGONIID^ {Gorgnnlas). 



In the Gorgonias or Bark-bcarhig Corals, the polype 

 mass is attached by a root, and is formed like a small 

 tree or shrub. Some of theGorgoniEe are very handsome, 

 much branched and reticulated. These species are com- 

 monly called " Venus' fans." In others the mass is not 

 much branched ; but the species are peculiar for having 

 the axis quite black and very hard, and are well known 

 by the common name of " Black Coral" {Anttpathea). 

 These were formerly much esteemed for their supposed 

 magical and medicinal qualities, but are now only used 

 for making riding whips and whisks, &c. The family 

 is represented in Plate 1, fig. 9, by the exotic species 

 Gorgonia palida. 



Family— TUBIPORID^ (or Organ Corah). 



The animals belonging to this family have at first a 

 tough skin similar to those of the last, which, however, 

 becomes in time so hardened by the continued deposi- 

 tion of calcareous matter within its substance, as to 

 assume the consistence of a hard coral. The animals 

 live iu groups side by side, and the shelly tubes formed 

 by them give the appearance of the pipes of an organ; 

 hence the English name for the family. These tubes 

 are of a vivid red, and the animals being bright green, 

 the mass forms a beautiful object when alive. The 

 family is represented in Plate 1, figs. 2-4, by the 

 species Tuhipora musica. 



Family— CORALLIID.E {The Calcareous Corals). 



In this family a larger quantity of calcareous matter 

 is deposited along with the horny matter, and this 

 forms a stone-like axis, instead of a horny one, as in 

 Gorgonia. 



Genl'S Corallium. — This genus is the type of the 

 family. To it belongs the celebrated red coral of com- 

 merce, Corallium rubrum, a native of the Mediterranean, 

 and represented in Plate 1, fig. 6 — Isis nohilis. This 

 coral, so much admired for its fine red colour, and the 

 high polish of which it is susceptible, is tlie article so 

 much used for making beads and other trinkets. It 

 forms a very profitable trade in the Mediterranean, and 

 is procured by dredging and diving, the fishery thus 

 giving employment to numbers of people. 



Family— HYALONEMID^ {The Glass-rope 

 Corals). 



In this family (consisting of only one genus and a 

 single species) the axis is composed of a bundle of thin 

 transparent fibres, looking exactly like a rope of spun 

 glass. These fibres are formed of nearly pure flint, 

 and are hard enough to scratch glass. This axis is 

 covered with a polypiferous crust as in Gorgonia. The 

 end of the axis is lodged in a species of sponge. Fine 

 specimens of the Hyalonema {mirahile f) from Japan 

 may be seen iu the British Museum. 



Family— PENNATULID^ (or Sea-pens). 



This family contains species which have the polype 

 mass free, floating in the sea, or having the naked part 

 of the stem sunk into the sand or mud on the coast. 



Genus Pennatula. — This genus contains those 

 species which float free, and which are well known 

 from their resemblance to a pen, by the name of " Sea- 

 pens." They have only a single axis, which pervades 

 their central stem, and tliis, which is called the shaft, 

 is subcylindrical. The animals come out from the 

 upper part of the side branches which emanate from 

 tins shaft, and which correspond with the plume of 

 the pen. These branches or plumes are twice pinnate. 

 This family is represented in Plate 1, fig. 12, by a 

 species belonging to the genus Renilla (i?. arnericana), 

 the polype mass of which is fleshy, with a kidney-shaped 

 expanded head, the animals coming out on the broad 

 flat sides. 



Genus Vikgularia. — This genus contains some of 

 the species which have the base of the stem sunk in 

 the sand. A beautiful species, the V. mirahilis, occurs 

 on our own coasts, the stem or polj'pe mass being 

 linear, elongate, like a rod or a quill deprived of its 

 feathers, the side branches being very small. 



Order III.— ANTHOZOA HELIANTHOIDA 



{Zoanthoid Polypes). 



The Zoanthoid polj'pes have the Polypes single, free, or 

 permanently fixed. They are fleshy, either naked or 

 encrusted with a calcareous polypidom, the upper sur- 

 face being crossed with radiating lamellie. The mouth 

 of these Polypes is encircled with tubulous tcntacula, 

 which, being disposed in regular circles and tinged with 

 various colours, represent not unaptly the petals of 

 some flowers. Their stomach is membr nious and fur- 

 nished with more or less numerous longitudinal folds. 

 They have no intestine, and no visible exit from the 

 stomach, except the mouth, by which the undigested 

 remains of the food are ejected, always enveloped in a 

 large quantity of a clear glairy fluid. They are ovipar- 

 ous, the ovaries being internal. 



This order contains an immense number of species, 

 some of which are well known to our readers by the 

 familiar name of Actinia-, and others by the not less 

 well known term of Madrepores and Corals. 



