MOLLUSCOIDA. 
55 
after storms, and also under stones between tide-marks. 
Evinces considerable and spasmodic muscular contractions. 
Ascidia sordida , Aid. & Hanc. 
[Plate IX. figs. 1 & 2.] 
Very plentiful in the deeper water attached to stones, shells, 
sticks, and seaweeds. One has placed itself on the anterior 
end of an empty tube of Pectinaria helgica and quite tilled it up 
(Plate IX. figs. 1 & 2). An elongated (club-shaped) variety 
is not uncommon. 
Ascidia depressa , Aid. & Hanc. 
Not uncommon on the under surfaces of large stones in tide- 
pools. In November specimens are often loaded with a 
pinkish-white creamy fluid, which appears to be made up chiefly 
of ova. The cellular border of each ovum is faintly greenish 
by transmitted light. 
Genus Molgula, E. Forbes. 
Molgula arenosa , Aid. & Hanc.; Alder, op. cit. p. 160. 
Abundant in deep water, and in the stomach of the cod and 
haddock. 
Genus Cynthia, Sav. 
Cynthia , n. sp. 
A nodulated Ascidian like a raspberry or small bramble 
occurred on the West Sands after a storm. Mr. Alder stated 
that it was not C. morns , but a species unknown to him. 
Cynthia grossularia , Van Beneden ; F. & H. Brit. Moll. 
i. p. 40. 
Very common on the roofs of rocky ledges, between tide- 
marks, where it becomes incrusted by many parasites. The 
development of this species is easily observed. 
