S T R /E A. 



Plati; XXV U. 



Species 66. (Fig. a, b, Mus. Hanley.) 

 OsTR^A S.VNDVICHENSIS. Ost. UstA oblonyo-trigond, 

 divaricatim, plicald, rugosd, albd, jwstice productd, 

 purpurea pictd ; plicis centralibixs magnis, latera- 

 libxis parvis ; cardine parvo, angvMo, valvidw 

 in/erioris producto. 

 The Sandwich Islands Ostp.^a. Shell ublong-trigoual, 

 divergently plicated, rugose, wliite, produced pos- 

 teriorly, painted with purple ; central plaits large, 

 the lateral ones small; liinge small, narrow, that 

 of the lower valve produced. 



SOWERBY. 



Hab. Sandwich Islands. 



This pretty small species has entirely the external 

 appearance of a Plicatula, and it is only on opening 

 the specimen and examining the hinge, that its con- 

 nexion with the genus Ostraea becomes ajiparent. 



Species 67. (Fig. a, b, Mus. Taylor.) 

 OsTR«A CRENULIFERA. Ost. tesld mulli/ormi, parvd, 

 subcovipressd, plerumquc oblongd, versus apicem 

 angustatd marginibus plicatis ; exltis albidd, intiis 

 subviridi, cardine parvo, trigono, valvuUe, in/erioris 

 plerumque acuminatim producto ; iinpr<:.'~sionibns 

 mMscularibus inagnis. 

 The CRENULIFERODS OsTRA\. Shell multiform, small, 

 subcompressed, generally oblong, narrow towards 

 the apex, with plicated margins ; whitish without, 

 greenish within ; hinge small, trigonal, that of 



the lower valve generally acuminately [iroduced ; 

 muscular impressions large. 



SOWEKUY. 



Hab. Red Sea. 



The latero-marginal plications are constant in all 

 the varied forms of this interesting little species, which 

 in other respects, particularly in the green tinted 

 interior, resembles Ostrcca Guineensis. 



S[iecies 68. (Fig. a, b, c, Mus. Hanley.) 



OsTRiEA PLICATA. Osl. testd compressd, solidd, ple- 

 rumque oblongd, purpurea slrigatd vel maculatd, 

 rugosd, ad marginem plicatd ; margine intiis 

 prope cardinem utrinque leviter crenatd ; impres- 

 sionibus muscularibus magnis ; cardine laio, val- 

 vidw in/erioris producto ; apicibus acuminatis. 



TuE PLAITED OSTR.E.V. Shell compressed, solid, gene- 

 rally oblong, striped or spotted with purple, 

 rough, plaited at the margin, slightly crenated 

 within near the hinge on both sides; muscular 

 impressions large ; hinge wide, that of the lower 

 valve produced ; apices acuminated. 



Chemnitz. Conch, f. 232. 



Ostrrea plicatula, Gmelin. 



Ilab. China, East Indies. 



The various forms which may be referred to this 



species are all plaited round the margin of both valves, 



but closely so, in the manner of the smaller Ostrcea 



aeni/era. 



September, 1S7 



