314 ESCHARID^. 



seems to be identical with the present, as " growing in 

 raised stems of a pumicose consistence," and mentions 

 that in one case a Serpula had " fixed itself upon such a 

 colony, where at last it was enveloped by the overgrowing 

 Bryozoon, and its calcareous shell, in the well-known 

 manner, was eaten away"*. The peculiarity in the mode 

 of growth exhibited by this Floridan form has not been 

 noticed either in Crag specimens or in those which have 

 been obtained on our own coasts. 



A species of Actinozoon presents us with a similar 

 habit to that of L. edax. This is a Zoanthus described 

 by Diiben and Koren under the name of MamiUifera 

 incrustata, which is commonly parasitic on shells tenanted 

 by a species of Pagurus. In all cases the shell is de- 

 stroyed after a while by some process of erosion or 

 absorption, the diffused basal crust of the zoophyte 

 forming a perfect cast of it, and affording shelter to the 

 crab f. 



An interesting peculiarity of the present species is the 

 special aperture with which the ooecium is furnished, and 

 which is placed at the upper end of the depressed area, on 

 its front surface. 



Another characteristic point is the extremely irregular 

 disposition of the zooecia. They lie in all directions, 

 without the least uniformity of plan — now turned this 

 way, now that, forming a confused medley, which con- 

 trasts strongly with the usually definite and methodical 

 grouping of the cells amongst this family. 



The first recent example of L. edax was obtained on 

 the coast of Devonshire ; and I have since dredged it off 

 Guernsey, where it has also been taken by Mr. Norman. 



* Floridan Bryozoa, pt. li. p. 64. 



t Hincks, Catalogue of Devon and Cornwall Zoophytes, Ann. N. H. ser. 3, 

 vol. ix. p. 304. 



