152 MEMBRANIPORID^. 



Localities. Antrim (Hyndman) : off Donaghadee, 32 

 fathoms (Mr. W. Swanston) ; Guernsey ; off the Deadman, 

 Cornwall, 60 fathoms ; South Devon (T. H.) : Birterbuy 



Bay (A. M. N.). 



The massive, often subclavate, spines and the avicula- 

 rium, which is of the Flustrine type, distinguish this fine 

 species from the other Membranipora. The avicularium 

 is always placed, as amongst the Flustra, immediately 

 above the zooecium, an a distinct area, which is in a 

 line with the cells. We have a similar form in M. corni- 

 gera. Through the present species and such a form as 

 Flustra denticulata, Busk, a very close relationship is 

 established between the families of the Flustridce and 

 Memhramjjorida. 



Membkanipora discreta, Hincks. 

 Plate XIX. figs. 8, 9. 



Membkanipora discreta, Hiiicls, Devon & Cornw. Cat., Ann. N, H. ser. 3, 

 ix. 200, pi. xii. fig. 1 (page 40, sep.). 



Zocecia ovate, separate, varying in size, and irregularly 

 disposed ; the margin cut into about twenty lobes, sup- 

 porting as many delicate, sharply pointed spines, which 

 bend slightly inwards. Omcia very small, globose, 

 frosted. 



In the only two specimens I have seen, the colonies con- 

 sist of very minute and inconspicuous groups of cells. 



Habitat. Shells from moderately deep water. 

 Localities. South Devon; Guernsey (T. H.). 



I do not identify the present species with Smitt's M, 

 lineata, forma discreta, which, so far as I can judge from 



