302 HISTORY OF BRITISH ZOOPHYTES. 
and Mr. Couch, the former of whom fell in with it in the 
northern, and the latter in the southern extremity of Britain, 
this Cedlipora is inferior to the last in height and breadth, 
of a more delicate fabric, and whiter in colour. 
6. Cettipora vitrina, C. W. Peach. 
Hab. Goran, Mr. Peach; Mount’s Bay, Mr. Couch. 
“This delicate and beautiful species is very small: it is 
encrusting, circumscribed, and rarely exceeding a quarter of 
an inch in diameter. The cells are small, transparent, 
vitreous or pearly in their appearance, and very irregularly 
arranged. The apertures are very minute and terminal, and 
cannot readily be seen even with a lens.” (Couch.) 
Genus XIII. LEPRALIA, Johnston. 
Gen. Ohar. Polypidom calcareous or membrano-calcareous, 
adnate, crustaceous, spreading circularly, formed of a layer of 
urceolate cells in juxtaposition, horizontal, and arranged in semi- 
alternating rows: aperture terminal, often covered with an oper- 
cular ovary.—Dr. Johnston. 
This is a very interesting genus, and a great favourite 
with zoophytologists, but it is an excessively puzzling one, 
owing to the minute points of distinction betwixt one spe- 
