of Edinburgh, Session 1879-80. 
465 
Ascidia meridionalis , n. sp. 
External appearance. — Shape somewhat variable, generally oval, 
the anterior end being slightly narrower than the posterior, flattened 
laterally, base rounded ; attached by posterior end and part of left 
side. Branchial aperture terminal, placed on a large conical papilla 
of which the apex is inclined ventrally and to the right. Atrial 
aperture to the right of or on the dorsal edge, and about one-third 
of the way down, slightly projecting. Surface slightly velvety, with 
minute processes scattered over it. Colour light brown or horn- 
coloured. Length about 12 cm.; breadth about 8 cm. 
Test softish, tears easily, from 1 ’5 to 6 mm. thick, the left side 
being thicker than the right. Vascular trunks enter about the 
middle of the left side near the ventral margin, large vessels visible 
on the inner surface, which is smooth and shining. 
Mantle moderately muscular. 
Branchial sac minutely undulated longitudinally. Three small 
transverse vessels between each pair of large ones. Papillae, and 
generally smaller intermediate ones present. 
Dorsal lamina broad, ribbed transversely. 
Tentacles simple, filiform, about 60 in number, placed long and 
short alternately. 
Olfactory tubercle semilunar, horns pointing anteriorly. 
Several specimens from Station 320 (off the coast of Buenos Ayres), 
600 fathoms, and two specimens from Station 313 (Strait of Magellan), 
55 fathoms. 
Ascidia mentula , O. F. Muller. 
This species was obtained at four localities at Kerguelen Island, in 
depths of from 10 to 60 fathoms. 
Ascidia vasculosa , n. sp. 
External appearance. — Shape very irregular, somewhat quadran- 
gular, depressed ; anterior end a little prolonged and narrowed. 
Attached by the left side near the base. Branchial aperture net 
quite terminal, being on the right side of the anterior extremity. 
Atrial aperture also on the right side, nearer the dorsal than the 
