REPORT ON THE GASTEROPODA. 411 



which are parallel to the axis of the shell ; the lower row of these is the larger, and they 

 give the appearance of a shoulder : the spirals are most squarely prominent on the ribs, 

 but are faintly continuous in the intervals ; they are parted by square furrows of the same 

 breadth as themselves ; the surface of the shell is also finely scratched : below the spiral 

 bands is a broad low swelling which curves round the pillar ; it indicates the old canal, 

 the former concave lines of whose edge form strong scores across it. Colour pale buff, 

 with faint chestnut mottlings, which are concentrated and darkened in two distinct deep- 

 purple bands in the middle of the last whorl, with fainter traces of two more below and 

 another above near the suture ; all these are vague in their limits. Spire raised, conical, 

 scalar. Apex small, consisting of 3^ embryonic whorls, which are polished, turbinated, 

 and end in a fine, round, raised point ; they are slightly iridescent ; where they join the 

 normal whorls there is indication of that thickening of the lip which is common in the 

 embryonic shell of Cassis. Whorls (on the not quite adult specimen) 8, exclusive of the 

 embryonic whorl ; they rise high and constrictedly on each previous whorl, of which they 

 leave but little uncovered ; they are of very slow increase, the last is very little tumid, 

 and that almost entirely above, its greatest breadth being at the third spiral ; still they 

 are convex throughout till near the point of the base, when the contour-line is slightly 

 hollowed in passing over to the prominent but not lengthened nor narrow snout. Suture 

 is a fine, angularly impressed, irregular line, much disturbed by the buttress-like ribs. 

 Mouth long and narrow (but immature), pure porcellanous white within, but stained with 

 the purple bands. Outer Up leaves the body at a right angle, but turns almost imme- 

 diately to run parallel to the axis, thus forming a short narrow canal ; from this point it 

 curves equably to the point of the shell, which is obliquely cut off upwards, forming a 

 broad open canal. Inner Up spreads a little on the body in a porcellanous glaze, narrow- 

 ing to a sharp point in front ; its direction is almost straight in an oblique direction to 

 the extreme point, being only slightly concave in the middle. H. 1*6 in. B. 0*9. Pen- 

 ultimate whorl, height 0'14. Mouth, height 1-37, breadth (P32. 



In form and colour this is very like Oniscia cancellata, Sow. ; but in sculpture it is different, 

 having the longitudinals much more numerous and the spirals much less sharp, especially less pro- 

 jecting at their intersection with the longitudinals ; the spire is much lower, the edge of the last 

 whorl projects much less sharply, and the spiral at the shoulder does not project nearly so much as 

 the first spiral below this point. In the upper whorls there is not the sharp reticulation which is 

 found in Oniscia cancellata, from the intersection of the spirals by the sharp longitudinals. In that 

 species, too, the embryonic apex is quite different, being a coarse flattened somewhat shapeless and 

 much larger bulb, and having at the outside only 1J whorls. 



Oniscia grandis, A. Ad., is much rougher, the spirals are more numerous and higher, the spikes 

 on the spire are not so strong, nor do they run parallel to the axis, and the apex has fewer whorls. 

 Oniscia denisoni, Reeve, has all the spirals mucronated at their intersection with the longitu- 

 dinals. 



