318 HISTORY OF BRITISH ZOOPHYTES. 



Greville from Orkney, and I have repeatedly got specimens 

 of it on the coast of Ayrshire and of Arran, covering a con- 

 siderable space of bivalve shells with cells of the purest 

 white. The cells are oblong, depressed, the space betwixt 

 them punctured. The aperture is sometimes with a sinus 

 on the upper lip, sometimes with a denticle; at times 

 with a plain margin, and at other times with two spines on 

 the under lip. 



25. Lepralia fenestralis, R. Q. Couch. 

 Hab. On stones, Cornwall, R. Q. Couch. 



Cells urceolate, with longitudinal and transverse lines, 

 giving a net-like or window-Uke appearance, covered with 

 a transparent membrane, which Mr. Couch says is best seen 

 when dry. 



26. Lepralia nitida, Br. Fleming. 



Hab. On shells and Lcunhiarice, rare. Dr. Fleming ; Isle 

 of Man, Prof. E. Forbes; Scarborough, rare, Mr. Bean; 

 Devonshire, common. Rev. T. Hincks; Cornwall, Mr. 

 Peach; Strangford Lough, Mr. AV. Thompson; Berwick 

 Bay, Dr. Johnston; coast of Ayrshire, coast of Devon, 

 coast of Ross-shire, D. L. 



This is perhaps the greatest beauty of this beautiful 

 family. It even surpasses L. amiulata, so much and so 



