S T R .E A. 



(Fig. 4. a, h, Mus. D'Orb. in Brit.) 



In figuring tliese two shells it was intended to repre- 

 sent as a distinct species the OstrcBa Puelcha7iaoi D'Or- 

 bigny, who has so named the specimens. I cannot, 

 however, on further consideration, regard them in 

 any other light than as intere.'^ting varieties of the 

 South American Ostrcea parasitica. 



Sp, 



•20. (iMus. Brit.) 



0sTR.4;.\ DiscoiDEA. Ost. leslA rolundA, complanatA, 

 tenuiter striatd, albo-fulvescenti, pallide pur- 

 purea radiatd, subcequivalvi ; carding parvo ; 

 valvidd in/eriori convexd, ii)i]»-essioiie muscu- 

 lari maximd ; valvidd superiori valde compressd. 



The discoid Ovsteu. Shell rounded, ilattened, finely 

 striated, whitish brown, rayed with pale purple, I 

 subaeqiiivalve ; hinge small ; lower valve convex, 

 muscular impression very large ; upper valve 

 miich compressed. ; 



Gould. 



Hab. Fijee Islands and New Zealand. j 



A rounded species with a flat upper valve and very 

 contracted hinge. ' 



Januarv 



Species 27. 



OsiK^A Ano.\ssi. Ost. testd magna, compressd ro- 

 tundo-suhtrigond, cinered, vershs margines vix 

 purpured, incequivalvi ; intus albd ; valvvld in- 

 feriori crassd, costatd, margine expanso, laqueato 

 limbo cceruleo ; valvuld superiori depressd, squamis 

 latis, tenidbus, Icevigatis, versus margines laqtieatis 

 armatd ; cardine lato, complanafo ; imjiressione 

 musculari utrdque valvd magnd. 



Axgas's Ostr^a. Shell large, compressed roundly 

 subtrigonal, cinereous, a little purple towards the 

 margins, insquivalve, white within ; lower valve 

 thick, ribbed, its margin expanded, fluted, with 

 bluish border ; upper valve depressed, armed 

 with broad, thin, smooth scales fluted towards the 

 margin ; muscular impression large in both valves. 



SoWEIiBY. 



Eab. Port Jackson. 3Ir. G. F. Angas. 



The sculpture of this large species is much less 

 coarse than in equally large specimens of 0. edulis, 

 and the upper valve is more convex than in that 

 species. 



