106 



OsTREA Chemnitzii. Ost. testd obovali, plerumgue sinistrorsd, 

 valde compressd, solidd, nitidd, luted aut sordide rubro-purpU' 

 rnscente, subtuberosd, nonnunquam paululum subvesiculosd, nulUs 

 lamellis asperatd; margine pUcato, intusque persape scabro ; plicia 

 plerumque parvis ; superficie internd albido-virescente ; cicatrice 

 satis maynd, subreniformi. Long. 3 poli. 

 Hab. China ? Mus. Cuming, Hanley, &c. 



A species which is closely allied to rosacea, vith a peculiar resi- 

 nous gloss, and invariably attached by the entire surface of the lower 

 valve. The colour varies from dirty yel]ow to duU reddisli purple, 

 The apices are not much attenuated. The figure 994 of Chemnitz 

 is a fair representation. 



OsTREA LACKRATA. Ost. tcstd clongūtu, soUd'iusculd, valde in- 

 (Equivalvi, haud lamellosd, ad yiates acutas angustatd, ad latera 

 basimque laceratd ; valvuld sujjeriore planulatd, sublcevigatd, aut 

 lutescente radiis sordide rubro-purpureis ornatd, aut rubro-pur- 

 pured radiis duobus centralibus nigrescentibus aream angustam 

 albidam includentibus ; valvuld in/eriore profundd, radiis latis 

 atropurpureis strigatd, costisque raris subangulatis armatd ; super- 

 ficie internd albidd, submargaritaced ; cardine denticulis nullis 

 munito. Long. 2 poli. 

 Hab. Senegal ? Mus. Petit, Cuming. 



Not uniike parasitica, but distinguishable by its claw-like lateral 

 projections. 1 have never met with any valves attached by the en- 

 tire surface, The duIl crimson specimens, adorned with two centrai 

 dusky rays, which usually enclose a narrow space of yellowish vvhite, 

 are peculiarly beautiful, 



OsTREA MULTiSTRiATA. Ost. testd suborbiculari, compressd, (equi- 

 valvi, solidiusculd aut svbtenui, vix lamellosd, brunneo-rufescente, 

 con/ertissime radiatim rugosd ; superficie internd valvulee superi- 

 oris nived, purpureo marginatu ; inferioris disco centrali rufo 

 pulcherrime tinctd ; cardine dentibus validis munito ; natibus haud 

 eminentibus ; cicatrice satis magnd. Long. 3"3 poli. 



Mus. Saul, Cuming, Hanley. 



The lower valves were attached by their entire surfaces to a ship 

 returning from the coast of Africa. 



OsTREA Megodon. Ost. tcstd fttlcatd, glabrd, solidu, subcEqm- 

 valvi, pallide livido-purpurascente, margines verstis plicatd ; plicis 

 anticis o aut 6, 7naximis, subangulatis ; posticis minintis, angulatis, 

 paucis, subobsoletis ; margine valde plicato, intusque magis minusve 

 scabro ; natibus incurvatis ; superficie internd allo-virescente, nun- 

 quam margaritaced ; cicatrice satis magnd, reniformi, Long. 5 poli. 

 Hab. Peru (Cuming). Mus. Cuming. 



A rare and extraordinary species, which bears not the slightegt 

 resemblance to any of the recent Ostrece. The narrovv sickle-shaped 

 contour and the gigantic marginai tooth-like folds form its most di» 

 stinctive characteristics. The adult specimens are attached by their 

 apices only. 



OsTBEA Pe8-tigris. Ost. tcstd ovuU, ūut ovūU-subtrigond, solidd, 



