502 ECHINODERMATA, 



ORDER II. 



APODA.(l) 



Our second order of the Echinodermata, or the Apoda, comprises 

 but a small number of animals closely related to the Holothuriae, 

 but which want the vesicular feet of the preceding order. Their 

 body is invested with a coriaceous unarmed skin. Several points of 

 their internal structure are not well understood. In 



MoLPADiA, Cuv. 

 As in Holothuria, we find a coriaceous body fonning' a thick cylinder, open 

 at both ends, and a tolerably similar internal organization; but independ- 

 ently of the want of feet, the mouth is destitute of tentacula, and is provided 

 with an apparatus of bony parts, but less complicated than that of the 

 Echini. 



MlNVAS, Cuv. 



Where the body is also destitute of feet and open at both extremities; but 

 its form is that of a spheroid depressed at the poles, and furrowed like 

 a melon. 1 can find no armature about the mouth. 



M. cyanea, Cuv. A beautiful species of a deep blue colour that inhabits 

 the Atlantic ocean. 



LiTHODERMIS, CuV. 



Where the body is oval and compressed posteriorly; its surface has the 

 appearance of being covered with a layer of stony granules, which form 

 an extremely indurated crust. The mouth is surrounded with tentacula, 

 and the intestines seem to be analogous to those of the Holothuriae. 



L. cuneus, Cuv. Blackish, and two inches in length. From the seas of 

 India, and the only species known. In the 



SiPUNcuLUs, Gm. 

 The body is cylindrical and elongated, the skin thick and wrinkled in both 

 directions. The mouth is provided with a sort of a proboscis susceptible of 

 retraction and protrusion by the action of large internal muscles. 



These animals are found in the sands of the sea, like the Arenicolx and 

 Thalassemac, and like them are used as bait by the fishermen. 



S. edulis, Cuv. This species is eaten by the Chinese inhabitants of Java, 

 who procure it from the sands by means of slender bamboos prepared for 

 the purpose. Other and rather small species — Sip. Isevis, Sip. verrucosus, 

 •Cuv. — :perfora4;e submarine rocks and live in their cavities. 



CI) Footless. 



