of Simple Ascidians. 365 
papille. Apertures tubular, short, yellowish, with red ocelli ; 
branchial one terminal, anal at a short distance down the 
ventral margin. Test soft, smooth, gelatinous, perfectly hya- 
line. Mantle delicate, pale yellow, and extremely transparent, 
all the visceral organs being distinctly seen through it; tubes 
short, cylindrical, and more highly coloured than the rest of 
the mantle. Branchial sac long, narrow, cylindrical, with 
rather long papille, non-plicate. Tentacular points of the 
ventral margin long, slender, numerous. Tentacular filaments 
numerous, long and slender, with short intermediate ones, set 
1n a single row on a narrow scalloped fold or collar. Length 
from 2 to 3 inches, breadth about 4 an inch. 
For specimens of this very distinct and interesting species 
we are indebted to Mr. A. G. More, who collected it in con- 
siderable abundance in Kilkieran Bay, Connemara, in 1869. 
The specimens were for the most part united towards the base 
into dense bundles, the upper portions being quite free. The 
aggregation is produced by the agency of the papille that 
clothe the sides of the basal extremity of the test; the attach- 
ment is consequently lateral. The common mass had appa- 
rently been fixed by the same means to some foreign body. 
The papille at the posterior extremity of the test, the pecu- 
liar ifiodé of aggregation, and the narrow cylindrical form of 
the body distinguish at once this species from C. intestinalis, 
from which it also differs in the respiratory tubes being further 
apart. 
Molgula simplex, Alder & Hancock. 
Body globular, subpellucid, nearly smooth, free, or very 
slightly attached. Apertures nearly terminal, not far apart, 
slightly tubular and retractile. Test rather soft, but tough, ge- 
nerally rather thinly clothed with linear fibrils, which are rarely 
forked, and seldom with any sand or shell adhering to them. 
Tentacular filaments branched, irregularly tripinnate; there 
are about eleven, with minute ones interspersed. Branchial 
sac with six folds on each side, the meshes distinctly but 
irregularly convoluted. Ventral plait smooth, broad below. 
Intestine forming two loops, confined to the lower half of the 
sac. Reproductive organs forming a slightly arched mass on 
each side, with the margins divided into numerous irregular 
lobes, that of the right,side within the second intestinal loop. 
Diameter 4 to 2 inch. 
A few specimens were found by the late Mr. Alder at Ply- 
mouth and Oban; it has also been obtained at Lough Strang- 
ford and Ballywater, Ireland, by Mr. W. Thomson. It has 
considerable resemblance to Ascidia ampulloides of Van Be- 
neden, which is undoubtedly a Molgula. That species appears 
