94 . III. DIST. CHAR. Form. 



c. ) 72. CORPORAL (corporate) a reliquium taking 

 the general form of the body of the original ; 



rendered moveable at the will of the animal through the 

 other, the tentacula of the animal are occasionally protruded. 

 (v. ambulacra.} 



Foramina (foramina) apertures distinct from those of the 

 mouth and vent, and only present in some certain species. 

 In the compressed or flat echini they are often large pervi- 

 ous holes, formed by the local coalescence of the opposite 

 sides of the shell their number varies from two to six. 

 Sutures (suturte) are the lines which mark the juncture of one 

 part of the shell with another part the crtist being composed 

 of many pieces, joined or articulated together the sutures 

 are dentate, serrate, &c. 



?.) Ambulacra (ambulacra) lines consisting of two or more series of 

 pores, disposed in regular forms, so as to divide the surface 

 of the shell into compartments or areas. 



Areas (areee) the parts which lie between the ambulacra. These 

 two last terms have been adopted by Linnaeus , with a reference 

 to the supposed resemblance between the surface of the shell 

 and a garden, divided by walks into beds or areas. The 

 number and disposition of the ambulacra and areas afford the 

 leading specific characters of the greater part of the echini. 



The APPENDICES (appendices} are parts attached to the crust: 

 these are the spines and teeth of the echinus. 



c.)Spines (spince} long, hard, moveable bodies, affixed by one end 

 to the surface of the crust They vary greatly in number 

 and shape are frequently marked with tubercles and lines 

 are obtuse or pointed; fusiform, subulate, clavate, c. 

 &c. On the death of the enclosed animal they usually 



