KEPORT ON THE GASTEKOPODA. 561 



2. Triforis levukcnsis, Watson (PL XXXIX. fig. 4). 



Cerithium (Triforis) levukense, Watson, Prelim. Keport, pt. 5, Journ. Linn. Soc. Lond., voL xv. p. 100, 



sp.il.) 



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



Shell. — Sinistral, sharply conical, with a narrow and produced base, solid, yellowish 

 white, glossy. Sculpture : Longitudinals — there are (on the last whorl) about 20 longi- 

 tudinal rows of round tubercles, which rows form a small rib across the whorl, and 

 are more or less continuous up the spire ; these continue on the base as strongly as on the 

 upper part of the whorls. These rows are parted by shallow rounded depressions. 

 Spirals — the longitudinal rows are cut by narrow little rounded grooves, whose inter- 

 section with them forms the tubercles. On the upper whorls there is only one such spiral 

 groove, so that there are only two tubercled spirals, but the groove gradually widens, and 

 there appears in the bottom of it a minute additional spiral, which finally becomes as 

 large as the other two ; on the base are three equally divided tubercled spiral threads, of 

 which the inmost is the smallest, and it ceases at the siphonal tube. Colour : the apical 

 whorls are amber, the rest of the shell yellowish white, with a narrow amber-coloured 

 thread within the contraction of the base of each whorl ; this spiral thread is not con- 

 tinuous, being interrupted by each of the longitudinal rows of tubercles. Spire high, 

 sharply conical, with a very slight convexity in its lines of profile, which are not perfectly 

 alike. Apex a narrow and perfect cone, ending in a small rounded point. It consists 

 of 6 small rather elongated narrow whorls, of which the first 1^ have about ten rows of 

 minute tubercles faintly connected by spirals ; the next 4^ whorls are crossed by about 

 24 longitudinal sharp little ribs, rising into points at the carina, which is a continuous 

 spiral thread. This carina on the first of these whorls is near the base, but later it rises 

 so as to encircle the upper part of the whorl. The minute spiral rows of tubercles, which 

 alone appear on the first whorl and half, cover the whole surface (both ribs and interstices) 

 on the later apical whorls. The regular sculpture does not begin abruptly and at once, 

 but a tongue of this new sculpture breaks across the top of the whorl, while the lower part 

 retains the earlier ornamentation. Wliorls 17, of very regular increase, flat on the side ; 

 the whole last whorl is contracted and a little elongated ; the base is narrow and flat. 

 Suture sharply impressed, and broader than the spiral grooves, being marginated on its 

 upper side by a minute flat surface, which runs round the base of the superior whorl. 

 Mouth almost more than perpendicular, square, with a largish auricle at its upper corner, 

 and a small and very transverse rift at the pillar. Outer lip sharp, thin, straight, per- 

 pendicular, angulated at the basal corner, flat across the base, turned in towards the 

 mouth and pinched in at the pillar, where it joins the pillar lip, closing in the side of 

 the small siphonal canal, whose edge is sharp and straight, or a very little contracted all 

 round. Pillar straight, then in front very much bent back, so that its posterior line 



(ZOOL. CHALL. EXP. — PART XLII. — 1885.) Tt 71 



