calyptrj:a 



Species 4. (Fig. 4 a, b, r, d, Mus. Cuming.) 

 Calyvtr^a bulla. Cali/p. testa suborbictdari, tenuis- 

 simd, pdlucido-albd, subconoided, coticenlrke plicato- 

 corrugald, vertice vix rostratd, undique pulcherrhne 

 radiatim lirato-striatd, sfriis striatulis conceniricis sub 

 lente siiblilmime fenestratis ; appendice interna bre- 

 viusculd, gracili ; valvd basali tenia, irregulari, opacd. 

 The bubble Calyptr«a. Shell nearly orbicular, very 

 thin, transparent-white, subconoid, concentrically pli- 

 cately wrinkled, scarcely beaked at the top, every- 

 where very beautifully radiately ridge-striated, striae 

 very finely latticed beneath the lens with concentric 

 finer striie; internal appendage rather short, .slender; 

 basal valve thin, irregular, opaque. 

 Hab. Island of Zebu, Philippines (attached to the under 

 surface of the ledge of a hard sandstone-rock) ; 

 Cuming. 

 An extremely delicate glassy shell, the elaborate latticed 

 texture of which, represented on a highly magnified scale 

 at Fig. 4 d, is quite marvellous when examined with a lens 

 before the light. It is, nevertheless, only a form of sculp- 

 ture which predominates with a peculiar typical exactness 

 under various phases in all the species. The basal valve, 

 seen at the lower edge of the piece of rock. Fig. 4 b, is but 

 a slight in-egular deposit of calcareous matter, void of any 

 regular sculpture. Fig. 4 a and 4 c represent the interior 

 and exterior of the sheO removed from its place of attach- 

 ment. 



Species 5. (Fig. So and hb, Mus. Cuming.) 

 Calyptr^ea dokmitokia. Calyp. testa ovatd, rude con- 

 vexd, margiae sinuatd, obliqud, vertice laterali, obtusa, 

 peUiicido-albd. snperne subferruginea, superficialiter 



corrvgatd, radiatim regulariter subtiliter striata ; ap- 

 pendice interna valde obliqud. 



The night-cap Calyptr^a. Shell ovate, rudely con- 

 vex, sinuated at the margin, oblique, vertex lateral, 

 obtuse, transparent-white, tinged with rust towards 

 the upper part, superficially wrinkled, radiately re- 

 gulariy finely striated; internal appendage very ob- 

 lique. 



Rab. Island of Burias, Philippines ; Cuming. 



An obliquely formed tumid species, rather crumpled at 



the margin, finely striated throughout. 



Species 6. (Fig. 6 a and 6 b, Mus. Cuming.) 

 CALYPTRi«A papyracea. Calyp. testa compresse ovatd, 

 tumido-conicd, obliqud, vertice postico, pellucido-albd, 

 radiatim subconspicui striata, undique peciiliariter cor- 

 rugafd, margine sinuatd; appendice internd, vaMe 

 obliqud. 

 The paper Calyptr.ea. Shell compressly ovate, swollen 

 conic, oblique, vertex posterior, transparent-white, ra- 

 diately rather conspicuously striated, everywhere pe- 

 culiarly wrinkled, sinuated at the margin ; internal 

 appendix very oblique. 

 A. Adams, MS. Mus. Cuming. 

 Hab. Philippine Islands ; Cuming. 



A light, swollen, compressly ovate species, very obliquely 

 grown, the vertex being quite posterior. The striae are 

 more conspicuously developed than in the preceding species, 

 and there is a peculiar wrinkled character about the sur- 

 face which does not appear to have arisen from any irre- 

 gularity of its place of attachment. The crumpling of the 

 margin is also characteristic. 



December, IS.'iS. 



