AND STAR-FISH. 171 



and I saw its limbs escaping through every mesh 

 of the dredge. In my despair I seized the largest 

 piece, and brought up the extremity of an arm with 

 its terminal eye, the spinous eyelid of which opened 

 and closed with something exceedingly like a wink 

 of derision !" The true " Brittle-stars " are dis- 

 tinguished by having their central disk covered 

 with a series of calcareous plates, in which is 

 situated the stomach. We have already mentioned 

 that the arms contain neither prolongation of the 

 stomach, nor ambulacral or sucking-feet. The arms 

 seem to be the special organs of locomotion, and 

 these are endowed with great flexibility, and are 

 able to twist and contort themselves in every possible 

 position, and pull themselves along. These arms 

 are defended by four rows of calcareous plates, one 

 row on each side, one above and one below. All 

 the internal organs are placed in the disk, except 

 the nerves, which ramify up each arm. The 

 Ophiura is a very short-lived species, and frequently 

 goes by the distinctive name of " Sand-star." The 

 true " Brittle-star " is Ophiocoma, which is much 

 longer-lived when it has the opportunity of 

 hiding up. 



There are several British species of the last 

 mentioned genus, among which Ophiocoma rosula is 

 the prettiest, and perhaps commonest, although the 

 " Granulate Brittle-star " (Ophiocoma granulatd) is 

 also very widely distributed. The latter lives in 

 deep water, and crawls along the sea-bottom by 



