Bittiuin.] GASTROPODA. 241 



1. Bittium cylindricum, Watson, 1881. Plate 14, fig. 11. 



Bittium cylindricum, Watson, J.L.S., xv, 118; Chall. Rep., xv, pt. 42, 

 478. pi. 30, f. 5 ; Man. Conch. (1), ix, 156, pi. 30, f. 18. 



Shell small, high, narrow, pointed, cylindrically conical, reticulate, 

 tubercled, strong, dark brown. Sculpture : Longitudinals there are 

 on the last whorl about 25 narrow, posteriorly convex, curved riblets, 

 which cannot be followed from whorl to whorl down the spire, and 

 which hardly appear on the base amidst the strong curved lines of 

 growth found there ; these riblets are parted by squarish furrows 

 about as broad as themselves. Spirals there are on each whorl 3 

 pretty equal, squarish, not prominent, spiral threads, which become 

 prominent themselves and give prominence .to the longitudinals by 

 expanding into round-topped tubercles as they cross the riblets ; they 

 are separated by furrows, which are of about the same breadth as 

 themselves ; the sutural furrow is slightly deeper and broader than 

 the others. The edge of the base is squarish, and is defined by a 

 narrow, sharpish-edged spiral thread. The base, which is flatly conical, 

 is plain but for the lines of growth ; the pillar is defined by a minute, 

 sharpish spiral thread, which runs round its top and meets the slit 

 of the canal. Besides these the whole surface of the shell is micro- 

 scopically scored with irregular lines of growth and fine spiral scratches. 

 Colour dark ruddy -brown, uniform all over. Spire high, narrow, 

 pointed, with straight but slightly angulated contour-lines ; the first 

 8 whorls expand regularly, so as to form a minute cone, while the last 

 4 expand more slowly, so at to give more of a cylindrical shape. Apex 

 small, blunt, rounded, slightly oblique, and a little immersed. Whorls 

 13, flat, except the last, which is slightly convex, with a somewhat 

 flat but conical base. Suture in the bottom of a deep furrow is con- 

 cealed by a projection of the inferior whorl. Mouth oval, with a small 

 rounded sinus at the upper outer corner, and a largish and deepish 

 canal running in behind the pillar. Outer lip not expanded, deeply 

 corrugated by the ends of the spirals, a deep V-shaped fissure forming 

 the canal. Pillar straight, not short, pretty strong, with a rounded, 

 narrow, twisted edge, and a small but not sharp point, which is very 

 slightly everted. Inner lip little more than a film on the body and 

 pillar. (Watson.) 



Diameter, 1-6 mm. ; height, 6-75 mm. 



Type in the British Museum. 



Hob. Foveaux Strait (A. Hamilton). The type is from Port 

 Jackson, 2-10 fathoms. 



2. Bittium exile, Hutton, 1873. Plate 14, fig. 12. 



Cerithium exilis, Hutt., C.M.M., 27. Bittium exilis, Hutt., T.N.Z.I., xvi, 214. 

 Shell very small, elongated oval, spirally lirate. Sculpture : 2 to 

 4 spiral nodular ridges, about 6 on the base ; between the ridges 

 there is usually a fine spiral thread ; the axial sculpture is only in- 

 dicated by the presence of nodules on the spiral line. Colour dark 



