PTEROCERA TRUNCATA. 
(Lot 210 and 857.) 
P. teste labio exteriore processibus 6 subequalibus armato; sprd 
truncatd ; margine, aperturdque intis fulvd, levibus. 
Outer lip with 6 nearly equal processes; spire truncated; aperture 
and margin smooth; the former within fulvous. 
Strombus truncatus, Dillwyn, p. 659. 8. 
Strombus Byronia, Gmelin, &c. (Young). 
Mr. Dittwyn has judiciously considered the 8. Byronie 
of Martini and of Gmelin to be the young of this shell, which 
is the largest of the present genus. 
2 
MITRA DIADEMA. 
(M. Coronata. Lot 437.) 
M. testd haud costatd, sulcis remotis, transversis, wntus punctatis, 
ornatd ; anfractibus coronatis; spire imcrassate, apertureque 
longitudine eddem; apice acuto; labo exteriore denticulato ; 
columella 4-plicata. 
Shell not ribbed, with transverse, remote grooves, punctured 
within; volutions coronated ; spire thickened, of equal length 
with the aperture ; outer lip toothed; pillar 4-plaited. 
Lamarck has already described a shell under the name of 
M. Corenata; I have, since the printing of the Catalogue, 
changed the specific name of this shell to Diadema, What 
Lamarck’s species really is, cannot be well ascertained, for 
the two figures to which he has referred are obviously 
widely different, not only from each other, but from this 
shell, with which, it seems, he was unacquainted. 
