88 ECIIINODERMATA. , 



by innumerable tubes and orifices. Some are universally or partially 

 covered with tufts, warts, scales, or spines. A kind of protecting mail 

 seems to prepare a number for resistance, while rugosities or asperities 

 yield to slightest pressure. Long and unmanageable rays, though subject 

 to ine^^table mutilation, entangle a certain division among foreign sub- 

 stances, at the same time that the strong, clumsy, thick and short ap- 

 pendages of another appear to defy violence. 



Amidst the great diversity distinguishing the external parts of the 

 star-fish, the use of a few may be explained ; but regarding the real pur- 

 pose to which the majority shall be converted, naturalists are still pro- 

 foundlv ignorant : Na}-, in some the external structure and appearance 

 are altogether unintelligible. It is continually changing during inspec- 

 tion, so that what forms the permanent, the principal, or the accessory, 

 can be scarcely ascertained. We behold a coriaceous, squamous, entire, 

 or porous integument, with innumerable shelly internal bones or joints, 

 besides rows of feet or suckers below. 



Equally singular ai'e the external and internal formation of the tribe. 

 Every comparative anatomist has found it so, as may be seen in the 

 works of Monro, Tiedrmann, Drllc Chiaie, and others. 



These animals are provided with numerous extensile suckers, some- 

 what of a cartilaginous nature, for the most part occupying a channel in 

 the under surface of each of the rays, and performing the office of feet 

 more obviously than attaching the body to the plane of position. By 

 their means specimens secure themselves to soUd substances, or pass 

 along from place to place. As the suckers in front affix, those behind 

 are relaxed from their hold, so as to allow progression. Though much 

 exceeding the specific gravity of the water, star-fish of various kinds 

 have a swift gliding motion, as if nearly buoyant. By means of absorp- 

 tion, the bulk of these creatures is considerably increased, and its specific 

 gravity diminished. But their hold is generally lost on privation of the 

 circumambient fluid, although some may be seen adhering to rocks on 

 recess of the tide, from inequalities retaining humidity. If the vessels 

 in our cabinets containing specimens be emptied, they soon fall from the 

 sides to the bottom. Thus, without \'iolence, which is alwavs attended 



