788 CLASS XIII. 
Sp. Acera carnosa Cuv., Ann. du Mus, 1.1. p. 10, Pl. 1. figs. 15—19, Mém. 
s. 1, Moll. 1.1. Pl. 2, figs. 15—19, R. Ani., éd. il., Moll, Pl. 35, fig. 2. See 
on another species from the Mediterranean, CANTRAINE op. cit. pp. 73, 74- 
Bulla L. (in part), Brug. Velum of head large, separated from 
mantle by a transverse furrow, in some produced into four laciniz 
or tentaculiform appendages. Vent, orifice of generation, branchiz 
and heart placed at the right side. Foot shorter than body, with 
lateral margin produced, undulato-plicate, Shell thin, convolute, 
with aperture large. 
Bullea Lam. (Philine Ascay., Lobaria Mvruu., GMEL., species of 
Bulla \..). Shell very thin, concealed, not affixed by muscles, with 
very wide aperture, and lip alone slightly involute. 
Sp. Bulla aperta L., GM. (in part), Lobaria quadriloba MUELL., GMEL., 
MuEtueR Zool. Danic. Tab. 100, figs. 1—5, Cuv. R, Ani., éd. ill., Moll., 
Pl. 35, fig. 1; in the Mediterranean and North Sea. 
Bulla Lam. (Scaphander Montr., Alicula Enrens., &c.) Shell 
external affixed by muscles, involute, with spire little exsert or 
depressed. 
Sp. Bulla ampulla L., Rumen. Amb. Rariteitk. Tab. 27, fig. ¢, BAIN. 
Malacol. P1. 45, fig. 12 ;—the apex is somewhat projecting in Bulla A plustre 
(Bulla Amplustre L.), Encycl. méth., Vers. Pl. 359, fig. 2, Buatnv. Malac. 
1.1. fig. 10, &c. There are also fossil species of this genus, almost all 
from the tertiary formations. 
Note.—Posterobranchea D’Ornieny. A genus related to the 
Acere, shell none, but differing from its congeners by the branchiae 
placed on the /e/t side. 
Sp. Posterobr. maculata D’ORBIGNY, Voyage dans VAmér, mérid. (reprinted in 
Oxen’s Jsis, 1839, pp. 526, 527; comp. also TRoscHEL, WiEGM. Archiv, 
1838, II. p. 282). 
The new genera Lobiger and Lophocerus Kroun, if indeed they 
belong to this family, must as it seems be placed near Aplysia. 
Comp. Kroun, sur deux nouveaux genres de Gastéropodes, Ann, des Se. 
nat. 3e Série, VII. pp. 52—60, Pl. 11. 
Family VII.  Cyclobranchiata. Gasteropods with branchiz 
foliaceous or pyramidal, arranged in rows on each side under the 
margin of mantle. Sexual organs without organs of copulation. 
