798 ‘ CLASS XIII. 
Note.—Genus Deshayesia Ravin (Guértn Magas. 1844, Moll. 
111), fossil, intermediate between Verita and Vatica, still appears to 
be more nearly related to the Vatica. 
Janthina LAM. Shell ventricose, thin, pellucid. Aperture 
triangular. Columella straight, produced beyond the margin of 
aperture. Animal with proboscis large, cylindrical, and two tenta- 
cles deeply cloven. A vesicular or spumose organ adhering to 
foot. Operculum none. 
Comp. on this genus, Cuvirr Ann. du Mus. XI. pp. 121—130, Moll., 
Mém. 15, pp. 2—10, figs. 1—8. 
Sp. Janthina communis, Helix Janthina L., Rumen. Amb. Rariteitk. Tab. 
Xx. fig. 2, Buainv. Malacol. Pl. 37 bis, fig. 1; in the Mediter. Sea and in 
the Atl. Ocean, in warm climates. The foamy organ at the foot serves for 
attaching the covering of the eggs, and, according to Rang, is afterwards 
cast off. Is this organ peculiar to the females? 
Scalaria LAM. Shell turrite, with ribs longitudinal, compressed, 
interrupted. Aperture rotundate, with margins connected, margi- 
nate, reflected. Animal with long retractile proboscis; eyes sessile 
at the base of tentacles. Operculum horny. 
Sp. Scalaria pretiosa LaM., Turbo scalaris L., RumpH. Amb, Rariteitk. Tab. 
49, fig. 4, GUERIN Iconogr., Moll. Pl. 12, fig. 11; the true winding stair, 
from the Indian Ocean ;—Scal. communis Lam., Turbo clathrus L., BLAINV. 
Malac. Pl. 34, fig. 2; in the Atl. Ocean, the North Sea, the Mediter. 
There are various fossil species from the tertiary formations. Comp. 
Lamarck Ann. du Mus. Vv. pp. 212—214, Vill. Pl. 37, figs. 3—5. 
Pyramidella Lam. Shell turrite. Aperture entire, semioval, 
with labrum acute. Columella with three transverse folds. Oper- 
culum horny. Tentacles broad, long, sulcate; eyes sessile at the 
base of tentacles. 
Sp. Pyramid. dolabrata Lam., Trochus dolabratus L., Buarnv. Malac. Pl. 
21, fig. 4, Cuv. R. Ant., éd. ill., Moll. Pl. 45, fig. 3 ;—Pyr. ventricosa 
Gusrin, Magas. de Zool. 1831, Moll. Pl. 2, &c. (Species marine, exotic.) 
Tornatella LAM. (in part). Shell convolute, ovato-cylindrical, 
frequently transversely striated. Aperture entire, oblong, with 
external margin acute. Columella plicate. Operculum horny. 
Sp. Tornatella fasciata Lam., Voluta tornatilis L., Encycl. méth., Vers. Pl, 
452, fig. 3, Buainv. Malac. Pl. 38, fig. 5, &e. 
Trochus L. Shell turbinate, with aperture sinuoso-quadrangu- 
lar, depressed, obliquely truncated. Animal with mantle often 
appendiculate on both sides. 
