798 CLASS xin. 



Note. Genus Deshayesia RAULIN (GUERIN Magas. 1844, Moll. 

 Ill), fossil, intermediate between NeritaandNatica, still appears to 

 be more nearly related to the Naticce. 



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, CUVIER Ann. du Mus. xi. pp. 121 130, Moll., 

 Mem. 15, pp. 2 10, figs, i 8. 



Sp. Janthina communis, Helix Janthina L., HUMPH. Ami). Rariteit/c. Tab. 

 XX. fig. 2, BLAINV. Malawi. PI. 37 bis, fig. i ; 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 BANG, 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. A, GUERIN Iconogr., Mott. PI. 12, fig. n; the true winding stair, 

 from the Indian Ocean; Seal, communis LAM., Turbo clathrus'L., BLAINV. 

 Malac. PI. 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. v. pp. 212 214, vin. PI. 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., BLAINV. Malac. PL 

 21, fig. 4, Cuv. R. Ani., ed. ill., Moll. PI. 45, fig. 3; Pyr. ventricosa 

 GUERIN, Magas. de Zool. 1831, Moll. PI. 2, &c. (Species marine, exotic.) 



Tornatella LAM. (in part). Shell convolute, ovate-cylindrical, 

 frequently transversely striated. Aperture entire, oblong, with 

 external margin acute. Columella plicate. Operculum horny. 



Sp. Tornatella fasciata LAM., Valuta tornatilis L., Encycl. meth., Vers. PI. 

 45 2 ; % 3, BLAINV. Malac. PI. 38, fig. 5, &c. 



Trochus L. Shell turbinate, with aperture sinuoso-quadrangu- 

 lar, depressed, obliquely truncated. Animal with mantle often 

 appendiculate on both sides. 



