262 RAPELLA. 



differing from Sphserulites, in having both the valves more 

 conical. 



EADIUS. Montf. A genus composed of Ovtjlum Volva, Anct. 

 and other simitar species, having a long attenuated canal at each 

 extremity. PL xx. fig. 442. 



RADIX, Montf. A genus composed of species of Limn^a, 

 having a short spire and wide aperture. — Ex. L. aperta, fig. 309. 



EADSIA. Grray. Chiton Barnesii, and similar species. 



EAMIFIED. {Ramus, a branch.) Branched out. — Ex. The varices 

 of some Murices, &c. 



EAMPHIDOMA. Schum. Pollicipes, Leach. 



EAMOSE. (Ramosus, branched.) Spread out into branches.) 

 Ex. Murex inflatus, fig. 395. 



EANELLA. Auct. (Eana, a frog.) Fam. Canalifera, Lam. 

 Siphonostomata, Bl. — Bescr. Oval or oblong, depressed, thick, 

 with two rows of continuous varices, skirting the outline, one 

 on each side ; spire rather short, pyramidal, acute, aperture oval, 

 terminating in a canal at each extremity ; outer lip thickened 



- within, crenulated, or denticulated, forming an external varix ; 

 inner lip spread over a portion of the body whorl. — Obs. The 

 shells composing this well-defined genus, are for the most part 

 covered with tuberculations, and granulations, and from the 

 colour and squat shape of some species, have been likened to 

 frogs. The Eanellse are mostly inhabitants of the East Indian 

 seas. The few fossil species known, occur in the tertiary beds. 

 The two continuous rows of varices skirting the spire, distinguish 

 this genus from Triton, which it nearly approaches, and into 

 which some species run by imperceptible gradations. Mr. Eeeve's 

 Monograph contains 50 species. PI. xvii. fig. 393, 394. 



EANGIA. DesmouHns. Gnathodon, Grray. 



SAP ANUS. Schum ? A genus consisting of spe^^ies of PTBTJiiA, 

 Auct. which are thin, much inflated, with short canals. P. papy- 

 racea. PI. xvii. fig. 389. 



EAPELLA. Sw. A genus of "Pyrulinse," Sw. thus described: 

 *' Shell ventricose, generally thin, almost globose ; the base 

 suddenly contracted, and forming a short canal, the channel 



