264 NATURAL HISTORY OP 



Hab. : Shetland {A. M. N.), Northumberland (Aid.), 

 Isle of Wight (Busk), Isle of Man, Devon, Cornwall 

 (T. E.), Dublin (Hassall), 



The cells are more or less rhomboidal, and regularly 

 arranged in straight rows. The orifice is circular, with 

 a notch or sinus. Below this is an avicularium of 

 varying shape, often mounted on a mucro or boss. The 

 cells are separated by distinct margins, and are usually 

 much punctured. Above the orifice are 2 — 4 prominent 

 spines. 



The colonies are red in colour, and are found on 

 shells and stones at varying depths. 



12. S. UMBONATA, Bush. 



Lepralia umbonata {Buslc, McA.). 

 Hab. : Shetland (Barlee). 



Described by Mr. Busk in the Q. J. M. S., viii., 143. 

 It appears to resemble very closely 8. auriculata. 



13. S. DiscoiDEA, Bush. 



Lepralia discoidea [Bush, McA., Hincks), Alysidota 

 conferta (BusJc). 



Hab. : Shetland, Hastings {Miss Jelly), Guernsey 

 (T.K). 



The cells are squarely ovate, distinctly punctured, 

 having a somewhat triangular orifice with a raised 

 margin. The cells are armed with six or seven spines, 

 and there is one (and sometimes a second) avicularium 

 on the front of the cell a little below the orifice. 



The smallest cells are in the centre of the colony. 

 This gives the zoarium a hollowed or depressed 

 appearance, which makes the species readily recog^ 

 nizable. 



The ocecia are hooded and punctured like the cells. 



14. S. siNuosA, Busk. 



