505 



Shell obliquely ovate, small, pellucid, horny, inflated, smooth, 

 subumbilicated ; spire distinct, flattened, whorls four ; columella 

 rather straight, anteriorly abruptly truncated ; aperture white, 

 dilated anteriorly. 



North America. Mus. Cuming. 



Sub-genus Hydatina. 



7. Bulla physis (pi. cxx. f. 9-11), Linn., Martin, t. 21. 

 f. 196, 197. Hydatina tilosa, Schum. 



B. animale fusco-rubro, margine pedis et appendicibus smarag- 

 dino-cyaneis. 



B. testa rotundato-ovata, perforata, tenui, subpellucida, lsevi, 

 albida, lineohs fuscis transversis undulatis picta, ; spira retusa. 



Animal of a clear red-brown, edge of foot and appendages of 

 an emerald blue. 



Shell rotundately oval, umbilicated, thin, semipellucid, smooth, 

 whitish, painted with transverse waved fuscous hues ; spire retuse ; 

 length 15 lines, breadth 11 lines. 



Mauritius ; on clear sand. Mus. Cuming. 



8. Bulla vuxillum (pi. cxx. f. 12, 13, 14), Chemn., Conch, 

 x. t. 146. f. 1348, 1349. B. fasciata, Brug. B. velum, Gm. 

 B. amplustre, Bom. 



B. testa subglobosa, tenui, subpellucida, albido-cinerascente, 

 fasciis fuscis trans versim picta, striis longitudinalibus tenuissimis. 



Shell subgiobose, thin, semipellucid, ashy white, painted with 

 transverse fuscous bands, with very fine longitudinal striae. 



Ceylon. Dr. Sibbald. Mus. Cuming. 



9. Bulla nitidula (pi. cxx. f. 15, 16), Lister, Hist. Conch, 

 t. 715. f. 74. Ferussacii, Quoy, Voy. de FUranie, Zool. pi. 66. 

 f. 10-12. 



B. testa ovali, imperforata, alba, nitida, lineis tribus, transversis, 

 rufo-fuscis, lineisque longitudinalibus, rufo-fuscis, undulatis picta, 

 transverse striata, striis subdistantibus, punctatis ; spira prominula ; 

 apice obtuso ; apertura ampla, postice angustata, antice valde 

 dilatata ; labio arcuato, antice rotundato. 



Shell ovate, imperforate, white, shining, with three transverse 

 reddish-brown lines, and numerous undulating red-brown longi- 

 tudinal lines ; transversely striated, striae rather wide apart, 

 punctated ; spire rather prominent ; apex obtuse ; aperture wide, 



4 d 2 



