i a 
MOLLUSCA. 795 
lamellate or cellular organ situated in the respiratory cavity near 
the gills, and of which the interspaces are filled by a slimy fluid. 
This organ, however, occurs in the male, although less developed’. 
Phalanx I. Capuloidea. Shell conical or orbicular, scarcely 
turbinate. Aperture very large, without any sinus or canal. 
Operculum in some none, in others subinternal. 
Sigaretus ADANS., Cryptostoma BuAINV. Shell orbicular or 
oblong, auriform, concealed under the foot reflected towards the 
back. Aperture ample, entire, with labium effuse, dilate, patent. 
Cavity of branchie furnished with a semicanal, in connexion with 
an incisure of mantle, and contaming two pectinate branchie. 
Head with two tentacles depressed, conical, furnished with a tuber- 
cle at the base. (Eyes none ?) 
Sp. Sigaretus haliotoideus Lam., Helix haliotoidea L., RumpH. Amb. Rari- 
teith. Tab. 40, fig. R, ADANSON Coquill. Pl. 2, fig. 2, &c. This genus is 
allied to Natica in the following division. 
Coriocella BLAINv. (Stgaretus Cuv., Lamellaria Montaau, 
Lovin. Shell with aperture ample, auriform, thin, horny, con- 
cealed under mantle. ‘Two eyes at the base of tentacles. Tongue 
armed with barbs, very long, spirally convolute. 
Comp. Cuv. Mém. s. 1. Mollusqg. No. 18, pp. 2—6, Pl. 1. figs. 1—8. 
Sp. Sigaretus Tonganus Quoy and Gatm., Astrolabe, Zool. 11. p. 217, Cuv. 
R. Ani., éd, ill., Moll. Pl. 49, fig. z, &c. 
Siphonaria Sow. 
Is this its place? Comp. Buatnv. Dict. des Sc. nat. Tom. 32, p. 267, 
Malacol. p. 475, REEVE Conchol. syst. 0. pp. 19, 20, MICHELIN in GUERIN 
Magas. de Zool. 1831, 1832. 
Calyptrea LAM. (and Crepidula ejusd.). Shell with aperture 
ample, orbicular or oblong, convex on the back. Branchial series 
single, of filaments often very long. Tentacles triangular; eyes at 
the base of tentacles towards the outside. 
Calyptraa Lam. Shell conoid with base orbicular. A calcareous 
lamina, conical or spiral, in the cavity of shell, and adhering to its 
apex. 
animals proceeded from them, but imagined, according to the notions then prevalent, 
that these originated from slime and putrefaction. De Hist. Animal. V. ¢. 15 initio. 
1 Cuvier Mém. sur les Mollusq. 1.1. p. 5, and fig. 3 f. 
