DIONE. 



Plate YII. 



Species 35. (Fig. a, b, Mus. Cuming.) 



PlONE CIRCINATA. Dioii. tedd roliindato-omtu, inlerdmn 

 suhtrirjond, rufcsceiile-pHrpurm, nonnimquam radiatd 

 vel alia, liris erectis concentricis undique deimiifani- 

 culata, liris ad lalera lain.inutis. 



The rounded Dione. Shell i-otumlately ovate, some- 

 times rather triangular, reddish-purple, sometimes 

 rayed or white, densely corded throughout with 

 erect concentric ridges, ridges laminate at the sides. 



Venus circinala, Born, Test. Mus. p. (jl. pi. 4. f. S. 

 Venus rubra, Gmeliu. 

 Venus Ouineensis, Ginelin. 

 Cytherea Guineeusis, Lamarck. 

 Ci/l/ierea allernala, Broderip. 

 Cylherea circinata , Sowerby. 

 Dione circinata, Deshayes. 



llab. Mazatlan. 



Of a uniform reddish-purple throughout, rusty towards 

 the martriu. 



Species 2G. (Mus. Cuming.) 



Dione kufescens. Bion. testa trixjono-omtd, miboblomja, 

 crassd, venlricosd,fuhescente-castaned, ad litnulam. el 

 areain. lujamenli riifescenle, concenlrice dense striata, 

 versus umbones Irevirjaid. 



The REDDISH Dione. Shell triangularly ovate, rather 

 oblong, thick, veutricose, fulvous-chestnut, riMldish 

 at the lunule and ligamentary area, concentrically 

 closely striated, smooth towards the umboes. 



Dione rufescens, Deshayes, Pro. Zool. Soc. 1S53, p. 2. 

 Cat. Mus. Brit. Conch, p. (57. 



Hab. Philippine Islands ; Cuming. 



A stout shell of a ])eculiar fulvous-chestnut eoloin-, red- 

 dish at the luiuile and ligamentary area, with somewhat of 

 the aspect of a Crassatdla. 



lavigntd, latere antico rerjulariter sidcato, sulcis U- 

 nearibns, sabdistautibus. 



The umboed Dioxe. Shell cordately ovate, thick, veu- 

 tricose, shining-violet, paler towards the umboes, 

 smooth, anterior side regularly grooved, grooves 

 linear, rather distant. 



Cylherea umbonelta, Lamarck, Anim. sans vert. vol. vi. 

 p. 319. 



Cytherea nivea, Ilanley. 

 Dione Hinboiiella, Deshayes. 



llab. Bed Sea ; Brazil. 



In this beautifully-tinted .shell the anterior linear grooves 

 are engraved with great regularity. 



Fig. 28 a, b (Mus. Cuming). 



The tivo shells here figured are the types of Mr. Brode- 

 rip's Cytherea allernala. M. Deshayes refers them in his 

 nionogni[)li of the Veiierid/e, in the British Museum Cata- 

 logue, to D. circinata, aiul on comparing them with that 

 species the affinity is obvious. They represent a variety 

 in which the reddish-purple is either rayed or altogether 

 wantin"'. 



Species 27. (Mus. Cuming.) 



Dione uiubonella. Dion, lestd cordato-ocatd, crassd, 

 ventricosa, uitente violaced, versus umbunes jiutlidiore. 



Species 29. (!Mus. Cuming.) 



Dione rose,^. Dion, lestd oblique cordatd, cumpressn, 

 ruseo-purpnra.'iceute, obscure fascia Id, concenlrice dense 

 liratd, liris ad lulus aiilicuiu hie illic lamellatis, ad pos- 

 ticniu. per maryineui. muricato-lamellatis, vix Sjiiiiosis. 



The rose DiojjE. Shell obliquely heart-shaped, com- 

 pressed, rose-purple, obscurely banded, concentrically 

 closely ridged, ridges here and there lamellated on 

 the anterior sule, on the posterior prickly lamellated 

 along the the margin, scarcely spined. 



Cytherea rosea, Broderip and Sowerby, Zool. Journ. vol. 

 iv. p. 364. 



Cytherea lepida, Chenu. 

 Dione rosea, Deshayes. 



llab. Panama. 



Tlds species partakes largely of the characters of the 

 group represented in the preeediug Plate. 



August, 1863. 



