LEPEALIA. 321 



from which its name has been taken, is a thick strong 

 spine, which turns up, nearly at right angles, from the 

 lower end of the cells. Two equally thick and strong 

 spines stand up in the same position, one on each side of 

 the mouth ; the two mouth-spines and tail not being per- 

 fectly upright, but inclining slightly towards eacli other. 

 The resemblance of many of the cells to a cockchafer or 

 tailed-beetle is very striking. I have only found L. melo- 

 lonfha on i\\Qflat shells of native oysters, and usually near 

 the joint end, in some little dip or hollow, where the polype 

 perhaps hoped to have his house and himself secure from 

 injury. But if so, we must admit that he is a very bad 

 judge of such matters, for the flatness of his favourite shell 

 exposes him to so many rubs and injuries that it is hardly 

 possible to find a specimen in which the tail and mouth- 

 spines are perfect; in so many cases they have been broken 

 off, leaving an aperture in their place. These accidents 

 have perhaps been the cause of the peculiarity of this 

 species not having been sooner noticed; for, deprived of 

 the mouth-spines and tail, it is difficult to discover any 

 difference between L. melolontha and L. 7iitida, except the 

 fact of L. melolo7itha growing in a branched figure, instead 

 of in alternate rows, as is the usual Lepralia fasliion." 



Y 



