liciij of li>ii(jal mill tlir Ariilniit Si'a. 1 Til 



porcam mcdiocrKer promiiioiitem forinans. Operculum testaoeum' 

 planum, margine externo curvato liria duabus instructo. 

 Longit. 19-5 mm., diam. 19. 



Hub. Station 333, Gulf of Manar, 101 fatli. 



The umbilical callosity forms a not much raised swelling 

 at the lower part of the opening ; in N. riifu it is higher up. 

 The flat operculum is not thick, and the two ridges upon the 

 curved margin are raised above the general surface and are 

 separated by a narrow deep groove. Within the inner ridge 

 and parallel with it the flat surface exhibits a few obscure 

 shallow sulci. Viewed from the front the upper part of the 

 shell is brown and the lower half white. 



Nat'ica simuluns, sp. n. 



Testa globosa, late umbilicata, alba, epidermide tenui olivacea 

 induta, laevis, lincia incremeuti obliquis striata ; anfractus 5-G, 

 couvexi, celeritor crescentes, ultimus supra subliumerosus ; aper- 

 tura obliqua, semicircularis, alba ; columella callo mediocritor 

 tenui labro juncta. Operculum corneum. 



Longit. 29 mm., diam. 27 ; apertura 20 longa, 11 lata. 



Hab. Stations 324 and 327, W. of Burmah, 448 and 419 

 fath. ; Station 280, off Coromandel coast, 44G fatli. 



In form resembling the British N. catena, but thinner, 

 without markings, and rather more widely umbilicated. The 

 lines of growth are slightly plicate beneath the suture and 

 upon the margin of the umbilicus, and there are faint traces 

 of very fine transverse striation upon the body-whorl. 



In the specimens from Station 280 the plicEe upon the 

 margin of the umbilicus are conspicuously strong, but in 

 other respects agree with the larger shell described from 

 Station 327. They are only 21 mm. in diameter, but may 

 not be full-grown. 



Natica incerta, sp. n. 



Testa obliqua, subglobosa, late umbilicata, alba, fascia latissima 

 dilute fuscescente circa anfractum ujtimum orr:ata, hevis, lineis 

 incrementi obliquis striata ; anfractus 5, celeriter accrescentes, 

 leviter convexi, ultimus magnus, antice paulo desceudens ; 

 apertura oblique semicircularis, intus pallide purpureo-fusco thicta ; 

 columella obliqua, fere rectilinearis, vel in medio leviter 

 prominens, superue callo crasso reflexo labro juncta. 



Longit. 26 mm., diam. 24 ; apertura 19 longa, 10 lata. 



Hab. Station 248, W. of Travancore, 224-284 fath., sand. 

 A widely umbilicated form, without any callous ridge 

 Ann. d: Mag. X. Hist. Ser. 7. Vol. xviii. 13 



