TUNICATA. 11 
This little species of Boltenia seems distinct from all other known species. It 
differs from the two species of the ‘Charcot’ expedition in having but few bars in 
the interspace between two branchial folds, in the condition of the dorsal lamina, and 
in other details of structure; and from B. bouvetensis, Michsn., of the ‘ Valdivia’ 
Expedition, in the number of branchial folds and in the structure of the dorsal tubercle. 
The minutely spinose surface of our species is also a notable peculiarity. 
In the same bottle with these specimens of Boltenia is a single specimen of 
a flattened, smooth Cynthiid (Plate VIL, fig. 12) with 4-lobed apertures (fig. 13), 
which is in such bad condition that further identification is impossible. The muscles 
of the mantle are the only internal organs that can be seen under the microscope. 
Possibly the animal may have been dead and decaying when collected. 
MOLGULIDZ. 
MoLGuLA HODGSONI. 
(Plate IIL., figs. 7-13.) 
Locality.— Winter Quarters, in McMurdo Bay, 10 fathoms, 22.11.02 ; one specimen, 
4x 2°2 x 2 cm. 
External Appearance.—Body pyriform, with a wider anterior and a narrow pointed 
posterior end (Plate III., fig. 7). Apparently not attached, or only very slightly so, by 
the posterior end. Atrial aperture terminal. Branchial a short distance back along 
the dorsal edge (fig. 7); both are on prominent siphons. Right-hand side more 
flattened and left side more swollen and rounded. Whole surface slightly roughened, 
with a sparse coating of sponge spicules and occasional shell-fragments and other 
foreign bodies. Colour a warm grey, becoming browner at anterior end. 
Test thin and membranous, but moderately tough, translucent, free on left side, 
but attached to mantle over the more muscular right side. 
Mantle rather transparent, but moderately muscular, the bundles being few, but 
very distinct (figs. 8 and 9). 
Branchial Sac with seven folds on each side, with four very wide bars on the 
fold, and four or five bars in the interspace ; occasional very wide transverse vessels ; 
stigmata curved and irregularly arranged, but never forming spirals or infundibula 
(fig. 11). 
Tentacles much branched, of two sizes, six or seven of each. The tentacles 
rather slender, with long delicate branches. 
Dorsal Lamina a plain narrow membrane, with no ribs nor marginal teeth. It is 
short, and rather inconspicuous. 
Dorsal Tubercle broadly cordate in shape (fig. 10), with both ends turned spirally 
inwards and the opening between them directed posteriorly. 
VOL. V. 
