MOLLUSCOIDA. 
45 
Membranipora Lacroixii, Sav.; Busk, Catal. p. 60, pi. 69, 
pi. 104. f. 1. 
On the inner surface of a valve of Gyprina islandica from 
deep water. 
Membranipora spinifera , Johnst.; Alder, Catal. Zooph. p. 53, 
pi. 8. f. 2, 2 a. 
Abundant on the under surface of stones between tide- 
marks. 
Membranipora Dumerillii , Aud.; Alder, Catal. Zooph. p. 56, 
pi. 8. f. 5. 
Not uncommon on bivalves from deep water. As Mr. Alder 
observes, it may occasionally be seen in company with M. 
Flemingii . 
Membranipora unicornis , Flem.; Alder, Catal. Zooph. p. 56, 
pi. 8. f. 6. 
On bivalves from deep water; not very common. 
Membranipora craticula , Alder; Catal. Zooph. p. 54, pi. 8. f. 3. 
Occasionally in deep water. 
Genus Flustrella, Gray. 
Flustrella hispida , Fab.; Johnst. Brit. Zooph. p. 363, 
pi. 66. f. 5. 
Abundant on the stems of Fuci and other seaweeds, and on 
stones between tide-marks. 
Genus Lepralia, Johnst. 
Aud.; Busk, Catal. p. 65, 
L. f. 1-5. 
Bather plentiful on laminarian roots thrown on shore after 
storms. Often forms a basis for other growths, and may be 
seen on their under surface when detached from seaweed or 
rock. 
Lepralia Brongniartii , 
pi. 8 
