REPORT ON THE GASTEROPODA. 535 



but oblique riblets on each whorl ; on the earlier whorls they are pretty continuous, with 

 a sinistral twist round the spire, but on the later whorls they become less regular. Besides 

 these there are fine scratch-like lines of growth. Spirals — on the upper whorls there are 

 four, on the later five, which, as they cross the riblets, rise into tubercles. They are 

 parted by intervals of two to three times their width, and in these intervals two or three 

 narrower but similar threads appear, as they do also on the base, where there are two 

 stronger circumbasal threads and a multitude of finer hair-like spirals, which extend to 

 the point of the pillar. Besides these the whole surface is covered with finely fretted 

 microscopic spirals. Colour a delicate waxy straw colour, with stains of a brownish flesh 

 tinge. Spire very slightly scalar, straight, and very sharply conical. Apex fine. Wlwrls 

 14, of slow increase and straight outline, with about one varix on each. Suture a very 

 little impressed at the base of each whorl. Mouth oval, with a sharp angulation at the 

 canal and at the upper corner, where the lip is sinuated and pinched in against the body- 

 whorl, and where the corner is further narrowed into a little canal by the strong tooth 

 which rises nearly on the interior basal thread. Outer lip sharp, fluted on the edge, 

 thickened by an external varix ; ascending a little at its junction with the body- whorl it 

 retreats so as to form a slight sinus ; it sweeps round with a very equable curve, advanc- 

 ing about the middle into a patulous wing-like projection ; across the base it is flat, 

 advancing, but scarcely patulous. The anterior canal is rather narrow and deep, short, 

 bent back, and with its front margin reverted all round except on the pillar. Pillar short, 

 angulated, and slightly twisted in front where it bends to the left, sharp-pointed. Inner 

 lip thickened, and forming a ledge along its whole length. H. - 8 in. B. 0'27, least 0"22. 

 Penultimate whorl, height 012. Mouth, height 0'2, breadth (P17. 



10. Cerithium lissum, 1 Watson (PI. XL. fig. 4). 



Cerithium lissum, Watson, Prelim. Report, pt. 5, Joum. Linn. Soc. Lond., vol. xv. p. 107, sp. 7. 



July 29, 1874. Levuka, Fiji. 12 fathoms. 



Shell. — Conical, rather stumpy, a little contracted and drawn out on the base, longi- 

 tudinally ribbed, smoothed, of a brownish-white colour. Sculpture : Longitudinals — 

 towards the apex there are on each whorl about twelve small, rounded, rather hunchy, 

 straight and regular ribs, parted by hollows broader than the ribs ; these very soon become 

 less regular, and, though larger, are less so relatively to the size of the whorls and to the 

 breadth of the hollows between them. On the penultimate whorl they become nodose, 

 especially on the lower part of the whorl, and on the last whorl they are almost entirely 

 replaced by unconnected rows of tubercles. The surface is very faintly scratched with 

 lines of growth. In the middle of the last whorl there is a pretty strong white varix, 



1 Xiaoog, smooth. 



