68 
Proceedings of the Royal Society 
Tentacles simple, there are twenty long ones with occasional 
small intermediate ones. 
Olfactory tubercle heart shaped, both horns turned inwards. 
Two specimens from Station 150 (south of Kerguelen Island), 
150 fathoms. 
Styela lactea , n. sp. 
External appearance .- — Shape nearly rectangular, from oblong to 
spherical, erect, not compressed ; anterior end straight and wide ; 
posterior end straight and nearly as wide ; dorsal and ventral edges 
slightly convex. Attached by the whole of the posterior end. Aper- 
tures both anterior, nearly sessile, four cleft ; branchial at the ven- 
tral edge of the anterior end, directed ventrally ; atrial at the dorsal 
edge of the anterior end, directed anteriorly and dorsally. Sur- 
face smooth, but seamed with tranverse creases and slight folds, 
longitudinal ones here and there. Colour creamy white. Length, 
4*5 cm. ; breadth, 3’5 cm. 
Test thick, but soft and flexible, quite opaque. 
Mantle closely attached to the test. Musculature fine, longitu- 
dinal and transverse bands intersecting at right angles. 
Branchial sac with four folds on each side. Internal longi- 
tudinal bars rather few ; about six on a fold, few and distant in the 
interspace. Meshes greatty elongated transversely, some of those 
near the endostyle containing thirty to forty stigmata, they are 
occasionally divided by a narrow horizontal membrane. 
Dorsal lamina plain, no ribs, margin even. 
Tentacles filiform, about thirty very long thin ones, with inter- 
mediate shorter ones. 
Olfactory tubercle large, transversely elliptical; both horns rolled 
inwards and forming large spiral coils. 
Three specimens from Kerguelen Island, 10 to 100 fathoms. 
Styela exigua , n. sp. 
External appearance. — Shape quadrangular, a little longer than 
broad, somewhat compressed laterally ; anterior end broad and 
nearly flat ; posterior rather narrower and more rounded. Attached 
