196 THE AQUARIAN NATURALIST. 



on oyster-beds, and some frequent the sand nearer to 

 the shore. On the whole they are extremely nume- 

 rous, and from the vast multitudes continually de- 

 stroyed, their race would seem to be inexhaustible. 



/ ' 



Some of the Ophiuri will feed voraciously on the 

 flesh of the mussel, which they seem to prefer to 

 the oyster, although the latter is by no means re- 

 jected ; nay, sometimes, so voracious is their appetite, 

 that, after a full meal, the centre of their disc may 

 be observed stuffed out like a cushion by repletion. 

 They have not, however, been observed to swallow 

 the shells of bivalves, although their mouth is suscep- 

 tible of considerable dilatation, and the capacity of 

 the stomach sufficient for their reception ; but when- 

 ever a part of the flesh of the mussel is within reach, 

 the extremity of one of the rays is soon twined 

 around it, and it is carried to the mouth and greedily 

 devoured. However ravenous at times, they will 

 occasionally pass many days without food. 



Mutilation is inevitably concomitant on impurity 

 of the water; but without any obvious cause we 

 witness it continually, and that to the most de- 

 structive extent. Piece by piece falls off from the 

 rays, until nothing but the disc remains, and yet the 

 animal still lives. After a specimen had been pre- 

 served some time, only a very short fragment of the 

 rays continued entire ; still the animal fed greedily, 

 nor was motion utterly extinct even when the disc 

 itself was partly decomposed. 



Early in April, the disc is seen remarkably full, 

 plump and round in the margin the space inter- 

 mediate between the rays being occupied by spawn, 



