1885.] 'lightning' AND ' PORCUPINk' KXPEDITIONS. 33 



with the youno; of any other species kaowa to me, and I have there- 

 fore named and characterized this species provisionally. 



10. Natica globosa', JeEfreys. (Plate IV. figs. 4, 4 a.) 



Shell globular, thin and fragile, semitransparent, and glossy : 

 sculpture, only some slight and close-set spiral striae which may be seen 

 under a microscope : colour white with a faint tinge of yellowish- 

 brown : spire short and pointed : whorls 4, tumid and compact ; 

 the largest occupies | of the spire : suture rather deep : mouth oval, 

 somewhat expanded, contracted and angular above, rounded below : 

 outer Up nearly semicircular, thin-edged : inner lip narrow, flexuous, 

 attached above to the pillar, and folded over the umbilicus, which 

 consists of a narrow slit. L. O'l, B. O'O/o. 



'Porcupine' Exp. 1870: All. St. 16, 17a; Med. 55. 



Distribution. Alarocco and C. Verd I. (' Talisman ' Exp.) ; 

 1192-1980 fms. 



B. Umbilicus more or less covered by a callus. 

 Neverita, Risso. 



11. Natica compacta^ Jeffreys. (Plate IV. figs. 5, 5 a.) 



Shell globular, thick, opaque, somewhat glossy : scidpture, a 

 few microscopical spiral siriiB, which are chiefly perceptible on the 

 base : colour light yellowish-brown : spire short, turreted ; apex 

 blunt : whorls 4, convex, rapidly enlarging, shouldered below the 

 suture ; the last occupies | of the spire : suture wide, slightly 

 channelled : mouth oval, equal in length to ^ of the spire : outer lip 

 inflected above : inner lip thickened on the pillar and at the base, 

 not forming a pad as in many of the other species : vmbilicns con- 

 cealed or closed by the inner lip. L. 35, B. 0'3. 



'Lightning' Exp.: St. 7. 



'Porcupine' Exp. 1869: 23, 23 a, 30. 1870: Atl. 16, 17, 17 a. 



Differs from N. montacuti in having a turreted spire, and 

 especially in the closed umhilicus. The very young are shaped like 

 the adult, but the umbilicus is open and free in consequence of the 

 inner lip not having been yet formed and spread over the pillar. 



12. Natica obtusa ^ Jeffreys. (Plate IV. figs. 6, 6a.) 



Shell oval, with an oblique outline, rather thick, opaque, and 

 glossy in the living state : sculpture, slight and curved striae in the 

 line of growth, which are stronger below the suture in each whorl : 

 colour whitish : spire short, apex very blunt : whorls 4, somewhat 

 compressed, but not flattened ; the last occupies g of the spire : suture 

 slight and shallow : mouth oval, acutely angulated above : outer lip 

 thick-edged : inner lip thickened in the only adult specimen, and 

 completely covering the umbilicus, which is partly visible in a half- 

 grown specimen. L. 0*3, B. 0*3. 



'Porcupine' Exp. 1870: Atl. St. 16, 17. 



' Globular. ^ Compact together. ^ Blunt. 



Proc. Zool. Soc— 1885, No. III. 3 



