ECHINODERMATA. 383 



empty shells, and, as is believed, devouring larger 

 ones out of their shells. So destructive is this 

 animal considered to Oysters, that in some old Ad- 

 miralty regulations, among other protective statutes, 

 a penalty is denounced against every one who, on 

 seeing the " Five-finger," does not either crush it 

 beneath his feet, or throw it out of the reach of 

 the tide. It appears from some observations of M. 

 Deslongchamps, that it pours into the shell some 

 poisoning fluid, and that then the animal is sucked 

 out by the insertion of some fleshy tubes which 

 project from around the mouth. 



The rays gradually becoming longer and more 

 slender, we are brought to those in which they are 

 so lengthened as to resemble the tails of so many 

 serpents, whence they are named Ophiurus.* The 

 feet are found only upon the small central part or 

 body ; but the long rays being very flexible are 

 used as legs to crawl upon, or even as fins, support- 

 ing the animal for a short time by a waving motion. 

 In succeeding genera, such as that called Medusa's 

 head, (Gorgonocephalus^ the central part is still 

 further diminished, and the rays are divided into 

 branches of great length and number. Each ray, 

 soon after its commencement, separates into two 

 branches, each of which, at a short distance, divides 

 into two more ; these again into two others, and so 

 on, to an astonishing extent. Upwards of two 

 thousand five hundred ramifications have been count- 



* "O<p/j, ophis, a serpent, and at>, owra, a tail. 



t Topyovts, Gorgones, the Furies, and xs<paX!, kephale, the head. 



