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 Cellipora is inferior to the last in height and breadth, 

 of a more delicate fabric, and whiter in colour. 



6. CELLIPORA 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. Char, Polypidom calcareous or membrane-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- 



