S T R ^ A. 



Plate XII. 



Species 24. (Mus. Brit.J 



OsTR^A MEGODON. Ost. testd solidd subcequivalvi, 

 obscure 2mr2nired vel viiidi fulvescenti, transverse 

 elmgatd, arcuatd, reniformi, margine ventrali 

 qumque ad sexplicatd, pHcis viaximis, rotimdts, ad 

 marginem externum perfoliaceis ; intus alhd, partim 

 subviridi; impressione /nuscutari magnd, reniformi. 



The large-toothed Ostr^ea. Shell solid, nearly 

 equivalve, dull purple or greenish fulvous, trans- 

 versely elongated, arched, reniform, ventral 

 margin with five or six plaits, very large, rounded, 

 foliated at the outer margin ; white within, partly 

 greenish ; muscular impression large, reniform. 



Hanlev. Proc. Zool. Soc, 1845. 



Ostrcea galliis, Valenciennes. 



Hab. Peru. 



t5pecies 25. (Mus. Brit.) 



OsTR^A RUFA. Ost. testd trigond, solidd, rugoso-sqm- 

 mosd, riifd, aut fusco-purpured ; ijit-ds medio fusco- 

 suipurpiired, ad marginem albidd ; valmdd inferiori 

 profundd, ad marginem vahain superiorem supei-anti ; 

 valvuld superiori subplamdatd, versics margine?!? 

 squamis brevibus crassis armatd. 



The rufous Ostr^a. Shell trigonal, solid, roughly- 

 squamose, rufous or brownish purple; within, 

 brownish purple in the middle, whitish at the 

 margin ; lower valve deep, overlapping the upper 

 at the margin ; upper valve rather flattened, armed 

 with short thick scales near the margin. 



Lamarck. Anim. sans vert. Ostrsa, No. 25. 



Ostreea tubercidata, Lamarck; Ostrcea Australis, Lamarck. 



Ilab. America, 



January, 1S71. 



