460 Transactions. 
Cymatium decagonium n. sp. (Plate 48, fig. 4.) 
Shell small, of somewhat squat appearance, with prominent spiral 
cords and distant axial ribs. Apex worn. Spire subequal in height to 
aperture with canal. About 3 post-embryonic whorls, obtusely angled 
submedially, each with 2 strong spiral cords on lower half and 2 much weaker 
ones on wide and sloping infrasutural space. Interstices much wider than 
cords, bearing 1-3 very fine and distant spiral threads. On body-whorl 
rather high, narrowly convex, and excavated behind between cords. Outer 
lip with sharp raised edge past varix, thickened and with 7 strong and 
subequidistant teeth within. Columella lightly concave, with 4 small plaits 
anteriorly. Tubercle on parietal wall very weak, but basal sculpture plainly 
shown. Canal very short (but seems to be broken and worn), turned 
slightly to left and backwards. 
к Height, 21 mm. ; diameter, 13 mm. ; height of aperture with canal, 
mm. 
Type (unique), from Waihao Downs, in Mr. R. Ө. Allan’s collection. 
This puzzling form does not compare well with any other New n 
fossil species. It does not seem to be an Austrotriton; the 2 strong keels 
on spire-whorls are not shown by A. maorium or other New Zealand species 
, p. From 
these, however, it is at once sundered by the absence of prickly knobs, the 
same in number, 
and therefore peripheral keel, on C. exaratwm is considerably higher up, 
so that the spire is much more ed. There is the same number of internal 
teeth on outer lip, and plaits on columella, and the same very weak parieta 
plait. Whether this resemblance is superficial or ancestral cannot be 
determined without study of intermediate forms. Neither C. exaratum nor 
any allied form has yet been found fossil in New Zealand. 
Charonia clifdenensis n. sp. (Plate 48, figs. 9a, 9b, 9c.) 
Shell small for the genus, fusiform, of rather distorted growth, thick 
and solid. Protoconch of 3 very convex, smooth whorls, the apical ones 
rather depressed so that shape is not so regular and conic as in Austrotriton 
maorium, &c.; separated from adult sculpture by slight varix. Adult 
whorls 7, the earlier ones faintly shouldered at lower third by a row of 
vertically-elongated nodules, 5 or etween varices; on lower whorls 
3or4 es past each varix become very strong and sometimes make 
penultimate whorl biangulate just above suture, but the other nodules 
