Bay of Bengal and the Arabian Sea. 165 



12. Lacuna indica. (PI. IV. fig. 7.) 



Testa umhilicata, sordide albida, spiraliter striata; anfractus 3, 

 celeriter eresceiites, perconvexi, ultimus magnus, antice obliqiie 

 descendens et subsolutus, circa umbilicum angustum acute cari- 

 natus, lineis incrementi oblique curvatis sculptus ; apertura 

 magna, alba, patula, late lunata, longit. totius -^-^ adaequans ; 

 columella obliqua, recta, incrassata, margine supero infra umbi- 

 licum paulo incurvato vel excavate ; labrum tenue, arcuatum ; 

 operculum membranaceum, tenuissime striatum. 



Longit. 10 miUim., diam. maj. 8, min. 5 ; apertura 7 longa, 5 lata. 



Hob. Off Madras coast, lat. 16° 01' N., long. 81° 2^' E., 

 in 410 fathoms. 



The strise are somewhat deeply incised, somewhat irre- 

 gular and ineequidistant, and quite evident to the naked eye. 

 There are about twentj-two upon the body-whorl. 



13. Natica rufa, var. (PI. IV. figs. 14, 14 a.) 



Hah. Off Calicut, Malabar coast, in 45 fathoms. 



The specimens from this locality are coloured like the 

 variety named N. Sioainsonii by Philippi, but differ in being 

 very much smaller and in having the umbilicus much more 

 closed up by the columellar callosity. These differences may 

 be merely the result of age, for the operculum of these small 

 specimens agrees exactly with that of larger shells. 



It is shelly, thickened, white above, but stained at the 

 spiral end with a dirty olive tint ; parallel with the outer or 

 curved margin are two grooves, leaving a flattened ridge 

 between them. The straight or columellar edge is peculiarly 

 striated and serrated ; the lower flat surface is covered with a 

 bright yellow epidermis. 



14. Sigaretus [Eunaticind) tener. (PI. IV. fig. 8.) 



Testa anguste rimata, ovata, subconica, tenuis, sordide albida, limo 

 ferrugineo plus minus induta, striis spiralibus tenuibus lineisque 

 incrementi cancellata ; anfractus 4, celeriter crescentes, convexi- 

 usculi, sutura subprofunda sejuncti ; apex saturate fuscus : anfr. 

 ultimus obliquus, elougatus ; apertura obliqua, longit. totius | 

 adaequans ; columella leviter arcuata, tenuis, superue angusto 

 dilatata et reflexa. 



Longit. 21 millim., diam. maj. 14, min. 10 ; apertura 15 longa, 

 10 lata. 



Hah. Bay of Bengal, 96 fathoms. 



This species is remarkable for its peculiar form and the 

 thinness of the shell. The nuclear whoil is of a deep brown 



