REPORT ON THE TUNICATA. 
291 
Both ova and a testis were found in the abdomen of the Ascidiozooids. The vas 
deferens is coiled spirally around the testis. Several very large tailed larvae (PL XL. 
fig. 13) were also found in the colony. In these the young test is very distinctly broken 
up into a network by numerous polygonal bladder cells (see PI. XL. figs. 13, 14). The 
tail and its urochord are both very distinct, although the larva figured is evidently in 
an advanced stage of development ; the three rows of stigmata in the branchial sac 
are already formed. Two pigmented sense organs are present, and the larva is pro- 
vided at its anterior end with three weU-developed adhering organs (PL XL. figs. 13, 15; 
the latter fismre shows the termination of one of the adhering organs on the surface 
of the test, highly magnified). 
I have given these details in regard to the specimens from Tangier Bay, as they may 
possibly turn out to be distinct from Verrill’s variety, although they are certainly closely 
alhed to it. To decide the matter both forms would require to be examined in the living 
condition. 
Lejptoclinum albidum, var. grande, nov. (PL XXXV. figs. 11-14). 
Tlie Colony is a large incrusting mass prolonged at its edges into considerable 
lobes and ridges with rounded ends. It is attached by the entire lower surface. The 
upper surface is uneven and is slightly rough all over. The colour is opaque whitish- 
grey. 
The length is 8‘5 cm., the greatest breadth is 6‘5 cm., and the thickness varies from 
1 mm. to nearly 1 cm. 
The Ascidiozooids are very numerous but small. They are arranged so as to form a 
close reticulum over the whole surface. A few common cloacal apertures are visible. 
The Ascidiozooids are placed vertically in the test. In the thickened portions they only 
occupy the outer layer of the colony. Their branchial apertures occupy slight rounded 
projections on the surface. 
The Test is hard and firm. It is relatively of large amount. It is of a dull greyish- 
white colour, and is quite opaque throughout. The matrix is densely crowded with 
calcareous spicules in all parts except in the immediate neighbourhood of the branchial 
apertures. Test cells are also abundant in the matrix ; they are of very small size, and 
are mostly rounded in form. No bladder cells are present. The spicules are large and 
are of regular stellate shape. The rays are long and have sharp points. 
The Mantle is rather thick and muscular. The branchial sphincter is well developed, 
and there are retractor muscles on each side of the body. 
The Branchial Sac is small. The stigmata are short, but regularly arranged. 
The Endostyle is narrow. Its course is straight. 
The Alimentary Canal is of small size. 
