DIONE 



Plate X. 



Species ',>9. (Mus. Cuming.) 



DlONE ALBIDA. Dion, testa oblongo-CHneiformi, valde iii- 

 (equilaterali, albidd, versus umbones ferntgineo tinctd, 

 conceidrice rude striatd, latere anlico brevissimo. 



The white Dione. Shell oblong-wedge-shaped, very 

 inequilateral, whitish, tinged with rust towards the 

 umboes, concentrically rudely striated, anterior side 

 veiy short, 



Pecfunculus albidus, Lister, Conch, pi. 373. f. 109. 

 Venus albida, Gmelin. 

 Ci/tlierea albida, Hanley. 

 Bioue albida, Sowerby. 



Hab. Jamaica? 



A rather solid compressed shell, of wedgc-lil^e form, 

 with scarcely any tinge of colour. 



Species 40. (Mus. Cuming.) 



Dione convexa. Dion, testa ovato-cnneiformi, compres- 

 siusculd, sordide alba, versus umbones ferrufjiiieo pal- 

 lidi tinctd, concentrice subrugoso-striatd. 



The convex Dione. Shell ovately wedge-shaped, ra- 

 ther compressed, dead-white, faintly tinged towards 

 the imiboes witli rust, concentrically rather roughly 

 striated. 



Vijtherea convexa. Say, Journ. Acad. Nat. Sci. Philadel- 

 phia, vol. iv. pi. 12. f. 3. 

 Cyihcrea Saijana, Conrad. 

 Bione convexa, Deshayes. 



Hab. Bay of Massachusetts ; Khode Island. 



A dead-white shell, of a more ovate form than that of 

 the preceding species, more coarsely striated. 



Species 41. (Mus. Cuming.) 



Dione rostkata. Bion. oblique cuneiformi, solidiusculd, 

 compressd, sordide alba, dense concentrice striatd, la- 

 tere poslico arcuato-declivi, antico brevissimo, abrupte 

 Iruncoto, uinbotiibtis roitratls. 



The beaked Dione. Shell obliquely wedge-shaped, 

 rather solid, compressed, dull white, densely con- 

 centrically striated, posterior side arcuately sloping, 

 anterior very short, abruptly truncated, with the 

 lunboes beaked. 



Ctjilierea rostrata, Koch, Phil. Abbild. Conch, p. 1.50. 



pi. 1. f. 3. 



Cylherea rostrata, Sowerby. 



Fenus Tehuelcha, D'Orbigny. 



Bione rostrata, Deshayes. 

 Hab. Brazil. 



Distinguished fi'om the preceding species by its very 

 abrupt wedge-like form, the anterior side being so short 

 as to impart a beaked character to the umboes. 



Species 43. (Mus. Cuming.) 



Dione alabastrum. Bion. testa ovato-cordatd, tenui- 

 cnlu, injtatd, Candida, ferrugineo vi.v tinctd, concen- 

 trice irregulariter corruguto-striutd, lunula et mnbo- 

 nibus subinnnersis. 



The alabaster Dione. Shell ovately cordate, rather 

 thin, inflated, white, scarcely tinged with rust, con- 

 centrically m-egularly wrinkle-striated, lunule and 

 umboes rather immersed. 



Hab. ? 



An elegantly-formed inflated species, with the lunule 

 and umboes more cordately immersed than usual. 



Species 43. (Mus. Cuming.) 



Dione citrina. Bion. testa subtri(jono-ov,atd, solidd, 

 citrino-luted, purpureo-violaceo postiee tinctd, nmbo- 

 nibus carneis, concentrice irregulariter corrugato- 

 striatd. 



The citron Dione. Shell somewhat triangularly ovate, 

 solid, lemon-yellow, tinged with purple-violet poste- 

 riorlv, umboes flesh-tinged, concentrically irregu- 

 lariy w^-inkle-striated. 



Chjtherea cilrina, Lamarck, Anim. sans vert. vol. vi. p. 30(5. 

 Dione citrina, Deshayes. 



Hab. Australia and Philippine Islands. 



Of a peculiai-ly delicate lemon colour, stained about the 

 posterior end with dark purple-violet. 



Species 44. (Mus. Cumuig.) 

 DiONESTKIATA. Bion. tesld orbiculuri-cunei/onni, solidci. 



October, 1S63. 



