EEPOET THE TUNIC AT A. 
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Locality. — Station 48, May 8, 1873; lat. 43° 4' N., long. 64° 5' W. ; depth, 51 
fathoms ; bottom, rock. 
There is only a single specimen (obtained on the Le Have Bank, off Nova Scotia, from 
a depth of 5 1 fathoms) of this species in the collection, and I am inclined to think that it 
is probably a stunted and abnormally shaped colony (PL XXVIII, fig. 11). From the 
small base of attachment it expands upwards to form a rudely pear-shaped mass, slightly 
flattened laterally, and connected with another mass of somewhat similar shape and 
about the same size by a narrow bar about 4 mm. in lenglh and 2 mm. in thickness. 
Possibly the colony was placed in an irregular crevice between stones. The colour is a 
dirty favm, upon which the pale brown bodies of the Ascidiozooids are scarcely fusible 
(PL XXVIII. fig. 11). 
The bodies of the Ascidiozooids are short, and are not distinctly dhdded into regions. 
They are usually about 1'5 mm. in length, and are quite opaque. Their anterior ends 
occupy shght eminences on the surface of the colony, which give it in places a somewhat 
roughened appearance. 
The test is rather remarkable in its minute structure. It is densely crowded with 
test cells, most of which are of very large size (PL XXVIII. fig. 12, t.c.). All the usual 
shapes are present, but circular and ovate forms are the most abundant, and many of 
them are very regular in their outlines. The opacity of the test is in all probability due 
to the presence of these cells. In the outer layers of the test a good many small sand- 
grains and minute fragments of shells, &c., may be found imbedded. 
The chief muscle bands in the mantle run longitudinally. There are only a very few 
muscle fibres in each band. The sphincter at the branchial aperture is rather feeble. 
The branchial sac occupies nearly half the length of the body, but it is narrow and in a 
lowly developed condition, the stigmata being few in number and of small size (PL XXVIII, 
fig. 13). The stigmatic cells are rather conspicuous. 
The ahmentary canal is not large, and it forms a short loop. The w’all of the stomach 
is folded. The post-abdomen does not extend far beyond the intestinal loop, and is not 
separated from it by any constriction. The vas deferens is a wide tube, which is 
conspicuous running along the dorsal edge of the post-abdomen and abdomen. 
In one of the Ascidiozooids examined, a single very large tailed larva (about 0*75 mm . 
in diameter) of nearly globular form was found in the dorsal part of the petibranchial 
cavity. 
Aplidium fumigatuin, n. sp. (PL XXVI. figs. 8, 9), 
The Colony is of ovate or elongated form, and is attached by the narrower end. 
Several masses may be united by their lower ends or by a short thick stolon. The upper 
end is broad and rounded, sometimes laterally compressed. The colour is a dull greyish- 
