CALTPTE^A.— Plate I. 



ternal appendage rather large; basal plate large, 



concave, platter-shaped, irregularly obscurely puckered 



at the edge. 

 Patella equestris, pars, Linnseus, Syst. Nat. p. 2.57. 



CalypirtBa equedris, pars, Lamarck. 



Calyptraa Roissyi, Dufo. 



LUhedaphiis longirostris, Owen. 

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



surface of masses of coral pressed to some depth in 



in the sand) ; Cuming. 

 It is impossible to determine which of the two or three 

 nearly allied forms of Calyptraa represented by this species 

 is the original type of the Linneean I'atella equestrk. The 

 shell which I assign to it, the same of which the animal 

 was described in 1843, by Professor Owen, under the title 

 of Lilhedaphus longirostris, corresponds the best with the 

 Lamarckian diagnose, " striis longitudinalibus acutis, un- 

 dulatis, subtuberculatis," though not with the Lamarckian 

 figures of reference; and it corresponds also best with 

 Dufo's C. Roissyi, which he describes as having the mar- 

 gin of the upper shell dentated, the extremities of the 

 ridges giving it that appearance. The basal valve of this 

 species takes the form of a concave platter, obscm-ely 

 puckered round the edge, without reference to the nature 

 of its place of attachment. The two specimens here figured 

 have precisely the same platter-like valve at the base, 

 though attached to very different substances. The speci- 

 men fig. 1 b, the upper valve belonging to which is repre- 

 sented above at fig. 1 a, is set in the bed of a solid coral 

 mass ; while the specimen fig. 1 c, with the upper valve 

 in situ, is attached to a sprig of branching coral. 



Species 2. (Fig. 2o and 2 b, Mas. Cuming.) 



CalyptEjEa tortilis. Calyp. testa suborbieulari, depres- 

 so-conicd, vertice obtiisd, Candida, sub lunte miiiutis- 

 sime radiatim striata, versus marginem peculiariter cor- 

 rugald, rugis timddis, valde promiscuis ; appendice in- 

 trrnd liiediocri. 



The crumpled Calyptr^ea. Shell somewhat orbicular, 

 depressly conic, obtuse at the top, wlute, beneath the 

 lens very minutely radiately striated, peculiarly crum- 

 pled towards the margin, the crumples being swollen 

 and very promiscuous ; internal appeudi.\ middling. 



Hab. Galapagos Islands ; Cuming. 



Strongly marked by a peculiar crumpling or shrivelling 



of the outer surface. 



Species 3. (Fig. 3 a and 3 b, Mus. Cuming.) 

 Calyptr^a cicatricosa. Calyp. testa orbiculari, de- 

 pressd, vertice parmn elevatd, tenui, Candida, sub lente 

 miniitissiiiie radiatim striata, coucentrice peculiariter 

 plicuto-corrugatd, rugis tumidis, irregularibus ; ap- 

 pendice intertid latiusculd. 

 The cicatriced Calyptrjea. Shell orbicular, depressed, 

 but little raised at the top, thin, white, beneath the 

 lens very minutely radiately striated, concentrically 

 peculiarly plicately crumpled, crumples swollen, irre- 

 gular; internal appendage rather broad. 

 Hab. Catanauan, Province of Tayabas, Island of Luzon, 

 Philippines ; Cuming. 

 An interesting species, of rather flattened growth, curi- 

 ously crumpled, but on a different plan to the preceding 

 species. 



