of Edinburgh, Session 1879-80. 
725 
posterior generally very narrow. Both apertures at anterior end, 
sessile, not lobed. Surface smooth, with occasional transverse 
wrinkles, especially on posterior end. Colour light yellowish-grey, 
nearly white. Length, 2 cm, ; breadth, *7 cm. 
Test thin, especially at anterior end ; transparent. 
Mantle moderately strong. 
Branchial sac simple, transverse vessels of one width, bearing 
horizontal membranes ; no internal longitudinal bars ; stigmata 
short, elongate-elliptical. 
Dorsal lamina . — Languets of moderate size. 
Tentacles short and stout, about twenty in number, alternately 
long and short. 
Olfactory tubercle small, irregularly oval in outline. 
One colony from Bermuda. Shallow water. 
Clavelina enormis , n. sp. 
External appearance . — Individuals united by their bases to form 
an irregular mass. Shape rudely oblong, with both apertures at 
anterior end. Surface smooth but irregular, especially on the 
posterior part. Colour greyish, with a slight brown tinge. Length, 
3 cm. ; breadth, 7 cm. 
Test moderately thin on the anterior half ; posteriorly thicker, 
wrinkled, and encrusted with sand. 
Mantle well developed. 
Branchial sac . — Transverse vessels all one size, with wide hori- 
zontal membranes hanging from them. Stigmata regular, short, 
and narrow, with rounded ends. Fine longitudinal vessels (inter- 
stigmatic) strong. 
Dorsal lamina . — Languets large, close, and numerous. 
Tentacles stout, long and short alternately ; about twelve of each. 
A single colony of four adult individuals and several buds. The 
united posterior ends form an irregularly-shaped base, which adhered 
to the surface of a mass of Balani, Synascidice , &c. Two of the 
adult individuals are united together along one side, so that their 
tests form a common investing mass. 
I am convinced that this is a pathological specimen, that the 
adhesion of the two individuals is abnormal, that the irregular 
