HOLOTHURIA. ECHINODERMATA. 397 



tubercular ; mouth terminal, surrounded with dilated tenta- 

 cula at the summit, the flattened part divided or dentated ; 

 anus at the posterior extremity. 



The FistulariiE are in general more tubercular than the Holothuria), and differ 

 from them besides in the particular form of the tentacula surrounding the mouth. 



F. elegans, Lam. With spreading, flattened, and divided tentacula 

 at the apex ; body papillose Lam. iii. J5. 



F. tubulosa, Lam. (H. tremula, Soland.) With spreading, flatten- 

 ed, and divided tentacula at the apex ; body slightly elongated^ 

 papillose above, and below with retractile tubes Lam. iii. 75. 



F. digitata, Lam. With digitated tentacula at the apex ; body cy- 

 lindrical ; papillae small, in the form of points. Lin. Trans, xi. 

 pi. 4, fig. 6. 



Gen. 4. HOLOTHURIA, Lam. Mull. 



Body free, cylindrical, thick, soft, very contractile ; skin coria- 

 ceous, generally papillose ; mouth terminal, surrounded with 

 tentacula divided laterally, branched or pinnated ; five calca- 

 reous teeth at the mouth ; anus at the posterior extremity. 



The animals of this genus are found on the shores of the sea among the rejecta- 

 menta. In some species, besides the papillae, are found retractile tubes, which are 

 supposed to serve for attaching them to marine bodies ; and in others holes around 

 the mouth for the same purpose. The body of the Holothuriae is perforated at both 

 ends, and the anterior extremity, in the centre of which is the mouth, is flattened. 

 From the posterior opening water is frequently projected. These animals are very 

 contractile, and have the power of withdrawing easily all their exterior organs, such ' 

 as their tentacula, their mouth, the papillae and tubes ; and their figure is often so 

 much changed by these contractions as to appear like an unformed mass. 



m.frondosa, Lam. Tentacula leafy ; body smooth. Lam. iii. 73. 



H. phantapus, Lam. Tentacula branching ; body narrowed poste- 

 riorly, and rough below with points Lam. iii. 73. 



H. doliolum, Lam. (Actinia, Pall,) With villose bipartite gra- 

 nular tentacula j body pentagonal, papillose.-r-.Law2. iii. 74. 



SECTION II. ECHINIDES. 



Crust immoveable and solid ; body subglobular or depressed, 

 without radiating contractile lobes ; anus distinct from the 

 mouth ; spiniferous tubercles immoveable on the shell, but 

 the spines moveable. 



In the animals of this section the intestinal canal has two openings. The mouth 

 consists of five double flattened solid columns striated transversely, with a dentated 

 edge towards the centre, and terminated anteriorly in an oblique point. These ten 

 plates, joined in pairs, are strengthened exteriorly at their base, towards the bottom of 

 the mouth, by fifteen narrower pieces, in such a manner that the twenty-five pieces 

 which compose this organ present the appearance of a reversed cone, of which the base 

 is interior, while the apex forms the entrance of the mouth with five oblique points. 

 This apparatus is calculated to break the food introduced into the mouth. The co- 

 vering is solid and immoveable, covered with tubercles, upon which are articulated 

 moveable spines of various form and size, according to the species. When the ani- 

 mal is dead the spines fall off, and the shell is found pierced with a number of small 

 holes, from which issue in the living animal rectractile tubes, which are projected at 

 will. These holes form on the shell porous bands disposed in pairs, which diverge 



