UMBRELLID&. 367 
of Pleurobranchea; anal opening behind the base of the gill; 
gill large, bipinnate, fully exposed on the right side, between 
the mantle and the foot. Distr.—K. obesa, Verrill. Atlantic 
Coast, United States. 
POSTEROBRANCH HA, d’Orbigny. 
Distr.—P. maculata, V’Orbigny (lxxxix, 91)... Coast of Chili. 
Animal shell-less;. oval, depressed, covered by a mantle 
broader than the foot; foot oblong, bilobed behind; branchial 
plume on the left side, projecting posteriorly ; reproductive 
orifice in front of gill, excretory behind; proboscis covered by 
a broad bilobed veil; no dorsal tentacles. 
Runcina (Forbes), Hancock. 
Syn.—? Pelta, Quartr. (not Beck). 
Distr.—On Conferve near high-water mark, Torbay; feeds 
apparently on Diatomacez. &. Hancochi, Forbes (1xxxix, 84; 
xei, 44). 
Animal minute, slug-like, with a distinct mantle ; eyes sessile 
on the front part of the mantle ; no tentacles ; gills three, slightly 
plumose, placed with the yent on the right side, at the hinder 
part of the back, beneath the mantle; gizzard armed ; reproduc- 
tive organs on the right side. Dentition (xiii, 70). 
Nepa, H. and A. Adams. 
Distr.—N. luniceps, Cuy. (Ixxxix, 85... South Europe. 
Animal shell-less; mouth terminating a proboscis, which is 
long and thin; oral veil half-moon shaped, with two lateral 
recurved tentacles. 
Susanra, Gray. 
Distr.—_S. testudinaria, Phil. (Ixxxix, 86). 
Mantle very large, broadly margining the foot, vesicular, 
deeply notched in front; frontal veil between the base of the 
tentacles and mouth large and oblong; foot oblong, rather 
narrow. Shell very small. 
‘Famity UMBRELLIDA. 
Shell depressed patelliform, thin, caleareous. 
Tentacles dorsal, ear-like, with plicate cavities at their bases ; 
mouth proboscidiform, retractile, covered by a small oral veil 
with moderate labial appendages, and concealed in the notch at 
the fore-part of the foot. Foot poet and abel a8 deeply fissured 
-- in front, the sides. tubercular. 
UMpretra:: Lam. 
Chinese ambrella: shell. 
eet -—Operculatum, Linn. (part). dene os astroplas, 
