102 EEV. E. BOOG WATSON ON THE 



the same as that between the longitudinal rows, so that each 

 group of four adjoining tubercles forms nearly a rhomb. Bound 

 the upper part of each whorl is an impressed flat surface, in 

 which, very near the suture, lies another smaller spiral, which 

 becomes minutely tubercled where it crosses the longitudinal 

 rows. At the bottom of each whorl is a very minute spiral 

 thread, which forms a pouting edge to the suture. Besides 

 these the surface is faintly reticulated by microscopic spirals 

 crossing the longitudinal lines of growth. This reticulation is 

 best seen on the flat and glossy base, which is unbroken except 

 by a small sharp spiral, about O012 in. within the edge. 

 Colour yellowish white, pure white on the upper part of the 

 spire ; round the base of each whorl is a suffused pale tint of 

 brown, which is more or less the colour of the base of the shell ; 

 the point of the pillar is white. Spire high, narrow, and conical, 

 slightly slewed to the left; so that while the left slope is 

 straight, almost concave, the right slope is just perceptibly 

 convex. Whorls probably 22, but of these the 3 or 4 apical 

 ones are broken off; they are of very slow increase, flat, con- 

 stricted on their upper part, flatly prominent in the middle, 

 and contracted at the lower part ; the base of the shell is flatly 

 conical. Suture strongly defined by the depression in which it 

 lies, but itself linear and projecting, being minutely marginated 

 both above and below. Mouth squarely oval, pointed above and 

 at the front of the pillar by the canal, which is small. Outer lip 

 broken. Pillar short, small, straight, scarcely excavated or 

 twisted, at the point sharp and slightly advancing outwards. 

 Inner lip. A very thin layer of glaze is carried across the body, 

 and turns round the pillar in a few microscopic lines, by which 

 alone it can be traced. H. - 6. B. 0"12. Penultimate whorl 0"072. 

 Mouth, length 0'08, breadth 0-06. 



This has a good deal the proportions of G. rnetula, Lov., with a 

 narrower base. It slightly resembles the Triforis Pfeifferi, Crosse, 

 and (apparently, for the B. M. tablet has more than one species on 

 it) the T. scitula, A. Ad., both from S. Australia ; but these have 

 only one series of gemmules, the upper row being very much 

 smaller, and in both the whole shell is very much smaller and 

 slenderer. T. gigas, Hinds, is a much thinner and less strongly 

 tubercled and sutured shell. T. angustissima, Desh. (Moll, de 

 Bourbon), is larger, broader in proportion, has the lower (in his 

 description " superieure," as he reverses the shell) row of tu- 

 bercles larger, and lacks the infrasutural flat constriction with its 

 small and finely tubercled spiral. 



