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, 2. Q. Couch. 
Hab. On stones, Cornwall, R. Q. Couch. 
Cells urceolate, with longitudinal and transverse lines, 
giving a net-like or window-like appearance, covered with 
a transparent membrane, which Mr. Couch says is best seen 
when dry. 
26. Lepratia nitipa, Dr. Fleming. 
Hab. On shells and Laminaria, rare, Dr. Fleming; Isle 
of Man, Prof. E. Forbes; Scarborough, rare, Mr. Bean; 
Devonshire, common, Rev. T. Hincks; Cornwall, Mr. 
Peach; Strangford Lough, Mr. W. 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 LZ. annulata, so much and so 
