254 
Z. ASCIDIOIDA. 
Yalkeria. 
the stones in them” — “ Among many other marine substances re- 
ceived fresh from the sea, in September 1753, this object happened 
to present itself under my magnifying glasses ; when, to my surprise, 
I found those grape -like bodies were a cluster of polypes, each hav- 
ing eight claws or tentacula, very lively, extending themselves about 
in pursuit of prey ; and upon their dying, the animals contracted 
themselves into their vesicles, which closed at the top : What we 
discover as a spot, is only the intestines of the polype with its food 
in it.” Ellis. 
3. V. imbricata, cells in dense clusters irregularly scattered 
on the polypidom. Adams. 
Plate xxix. Fig. 5, 6. 
Sertularia imbricata, Adams in Lin. Trans, v. xi. pi. 2. fig. 5 — 11. Turt . 
Gmel. iv. 683. Turt. Br. Faun. 216. Stew. Elem. ii. 450. Thomp. 
Zool. 111. 94. pi. 1. fig. 1-4 — Valkeria glomerata, Coldstream in Edin. 
New Phil. Journ. ix. 235. ph 2. fig. 1,2: and in Edin. Journ. Nat. and 
Geog. Sc. iii. 53 Serialaria imbricata et S. verticillata, Templeton, 
in Mag. Nat. Hist. ix. 467, fig. 66. 
Hab. Parasitical on various littoral Fuci. On Fucus nodosus 
in Milford haven, Adams . In small pools, at low- water, near Leith, 
Dr Coldstream. “ On the Fuci and Confervse, on the shore of 
Belfast Lough, near White-House Point,” Templeton. In the harbour 
of Cove, one of the most obvious and common species, J. Thompson . 
“ Stem simple, slightly branched, partly creeping, partly erect : cells 
ovate, lengthened, with the mouths slightly compressed quadrangu- 
larly, scattered over the stem in irregular groups. Before the polype is 
evolved, the cell is closed at the dislal extremity by a conical covering. 
Polypi with ten tentacula, finely ciliated : they extend considerably 
beyond the mouths of the cells, to the margins of which each is at- 
tached by a membrane, which is protruded before the tentacula when 
the polype is about to expand itself. When alarmed, it contracts 
very rapidly.” Dr Coldstream. — According to Mr Thompson this 
species creeps over the surface of the Fuci by means of its tubular 
ramifying roots, and throws off numerous flaccid irregularly branched 
shoots to the length of from one inch to one and a half or more, 
often so densely clustered as entirely to cover the plant on which it 
grow r s. 
4. V. pustulosa, vesicles clustered , unilateral . Ellis. 
Plate xxix. Fig. 7-9. 
Dichotomous tubular Coralline, Ellis, Corall. 54. pi. xxvii. fig. b. B — 
Sertularia pustulosa, Ellis and Soland. Zooph. 54. Turt. Gmel. iv. 
680. Bose, Vers, iii. 113. Stew. Elem. ii. 444. Turt. Brit. Faun. 
