468 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Test cartilaginous, transparent and smooth externally; 
stigmata very long and narrow, mostly in spirals; 
kidney broad but very short (Grand Banks only). 
intumescei^s. 
Body rounded, with diverging siphons; surface usually 
more or less covered with debris; intestinal loop bent 
in a very regular curve; stigmata long, forming many 
irregular curves and spirals in the spaces between as well 
as on the folds; six branchial folds, internal longi- 
tudinal vessels few manhattensis. 
Body longer than deep, thickly coated with debris; seven 
high branchial folds with many internal longitudinal 
vessels; stigmata long and fairly straight between the 
folds; kidney of moderate size, rather elongated. 
pannosa. 
Body covered with debris; seven branchial folds; stig- 
mata short and rather irregular in arrangement be- 
tween the folds; kidney elongated, very large (Grand 
Banks) septentrionalis. 
Caesira lutulenta, sp. nov. 
PI. 45, fig. 7-10; PL 73, fig. 168; text-figs. 2, 3. 
Body unattached, of elliptical outline, noticeably longer than deep, 
and not much compres.sed laterally, the largest specimen measuring 
Text-fig. 2. — Caesira lutulenta, sp. nov. X 3. 
about L5 mm. long by 12 mm. deep, and S mm. or more from side to 
side. Apertures rather near together on the dorsal surface and in 
the contracted preserved specimens generally projecting little if at all 
beyond the general outline of the body, though occasionally they are 
raised on small papillae. Branchial aperture with six, the atrial 
with four lobes. Test rather thin and soft though tough, of a deep 
greenish gray color in the alcoholic specimens and more or less trans- 
lucent, covered externally with vast numbers of fine soft moss-like 
branching processes which are best developed on the ventral portions 
