471 
of Edinburgh, Session 1879 - 80 . 
surface. Brancliial aperture at the edge, slightly to the right of the 
anterior end, 1 2 to 14 lobed ; atrial 8 or 9 lohed, both sessile. 
Surface smooth. Colour very light-grey, transparent. Length, 
6 cm.; breadth, 4 cm. 
Test thick, rather solid, transparent ; no vessels. Consists of hyaline 
matrix and small fusiform cells, no bladder cells. 
Mantle very thin, endostyle and viscera seen through distinctly. 
A few large distant muscular bands run round the right edge, and 
extend over the left side nearly as far as the endostyle. Atrial 
tube prominent and having fine muscle bands. Branchial also 
muscular, but not projecting. 
Branchial sac large, fills the whole mantle cavity. Every second 
transverse vessel slightly larger than the intermediate ones ; here and 
there the stigmata extend from the one large vessel to the other, 
cutting through the intermediate smaller one. The internal longi- 
tudinal bars widen at each intersection with a transverse vessel. 
Stigmata rather wide, three in each mesh. ISTo papillae at the corners 
of the meshes. Tusk-shaped ducts, to which horizontal membranes 
are attached, connect the transverse vessels with the swellings on 
the internal longitudinal bars. 
Dorsal lamina reduced to a series of conical processes (languets). 
Tentacles few, distant, small, and filiform. Two at each side of 
the anterior end of the endostyle, and a few others in the usual 
circle, but separated by nearly their own length from each other. 
Viscera on the right side of the branchial sac, at the posterior end, 
relatively small. 
Alimentary canal narrow. (Esophagus opens near the base of the 
branchial sac. Stomach short, wide, and barrel-shaped. 
Reproductive organs forming a large rounded mass on the right 
side of the intestinal loop at the ventral end. The ovary occupies 
the centre, and the spermatic vesicles are arranged round the peri- 
phery. The oviduct and vas deferens emerge from the dorsal and 
posterior end of the mass, and course along the superior (anterior) 
margin of the intestine to their termination. 
One specimen from Station 160 (South of Australia), 2600 
fathoms. 
This interesting form belongs undoubtedly to the AsciDiADiE 
