S T R .E A. 



Species 5('>. (Fig. a, b, c, Mils. Ilanley.) 

 OsTi'.^A PAL5IIPES. Ost. tesid compressUsimd suhquad- 

 ratd, tenui, valdc incequivalvi, in(equilaterali,fulvd, 

 purjmreo vel nigro radiatd ; latere ant ico b rev is- 

 dmo declivi, margine dorsali recto, margine ven- 

 trali suhrotundo, lobalo ; uvibonibus parvis, 

 acuminatis; valvuld superiori hevigatd, parvd ; 

 valvuld inferiori majits expant-d, extus radiatim 

 striata et distanter costatd ; costis septem, tubercu- 

 latis, ad margiiiem produclis, inlerstitii^ conipla- 

 natis. 

 The P.\lm-footed Osti!JE.\. iSliell much compressed 

 subquadrate, thin, very inequivalve, inequilateral, 

 fulvous, rayed with purple or black ; anterior side 

 very sliort, sloped ; dorsal margin sti-aight, ventral 

 magin rounded, lobed ; uniboes small, acuminated ; 

 upper valve smooth, small, lower valve more ex- 

 panded, radiately striated and distantly ribbed 

 without ; ribs 7, tuberculated, produced at the 

 margin, interstices flattoned. 



SOWERBT. 



Hah. Philippines. 



The peculiar characteristic of tliis rather pretty 

 oyster is found in the outer surface of the lnwcr valve, 

 which from the radiating ribs endiiij,' in l(;ln's and the 

 flattened surfaces between, [ireseiits ilic appearance of 

 the webbed foot of a bird. 



Species 57. (Fig. «, b, Mus. Ilanley.) 

 OsTRJiA KENiFORMis. Ost. testd cvassd, cloiigntd, an- 

 gustd, lateraliter amiKl,!, tilbidil, incequivalvi; 

 valvuld superiori ami/'nss.i. tumpUmatd, prpio 

 margines sub/uliaced, inli/s /mf/mrt'o marginald ; 

 valvuld inferiori profiuide cxcaratd ; margine 

 ventrali utrdque valvd acuminata, margine cardi- 



nuli recto ; impressioiiilms innscidarihus purpurco- 

 nigrescenlibus. 

 The i;eniform Ostu.ea. Shell thick, elongated, narrow, 

 laterally arched, whitish, inequivalve ; upper 

 valve compressed, flattened, a little leafy towards 

 the uuirgins, edged within with purple ; lower 

 valve deeply excavated, ventral margin in each 

 valve acuminated, hinge margin straight, mus- 

 cular impressions blackish purple. 



SOWERIIV. 



Hab. ? 



The specimen is peculiarly arched inwards on the 

 posterior, and outwards on the anterior side. 



Species 58. (Fig. a, b, Mus. Ilanley.) 



OsTRjEA LENTiGiNosA. Ost. lestd obUque ovato-subor- 

 hiculari, subleiUicu/ari ; albidd, subrugosd, intus 

 luteo ■punctatd, marginibus radiathn striatis, ex- 

 2)ansis, sublaqueatis ; impressio/nibus inuscularihus 

 rolundis ; cardine elongato, angusto, recto ; latere 

 antico brevi, rotunda ; latere postlco producto, 

 valvd inferiori foliaced. 



The freckled Ostr^ea. Shell obliquely ovate-subor- 

 l:)icular, sublenticular; whitish, rather rough, inside 

 spotted with yellow, margins radiately striated, 

 expanded, a little fluted ; muscular impressions 

 rounded; hinge elongated, narrow, straight; an- 

 terior side short, rounded ; posterior side pro- 

 duced ; lower valve leafy. 



SoWERBV. 



Hab. ? 



The interior surface of this species is distinguished 

 by a sprinkle of yellowish or purplish spots. The shell 

 is otherwise of a dull stone-coloured white. 



September, 1871. 



