90 Couthouy's New Species of Mollusca 
rior edge, thickened and rounded towards the base, callus 
depressed, reflected upon and filling the umbilicus, which 
is very small, and in mature specimens entirely conceal- 
ed, so as to give the shell the aspect of being imperfo- 
rate. Internal color a fine white; operculum calcareous, 
smooth and white, with transverse microscopic strie. 
Osservations. This shell was taken in great num- 
bers, from fishes caught near Nahant, and a few small 
specimens, off Cohasset. It doubtless exists, in deep 
water, in all parts of our outer bay, and may proba- 
bly be found along the whole coast of New England. 
Its bony operculum, and the entire consolidation of the 
umbilicus, distinguish it from any of our known species 
of Natica. It may possibly be an inhabitant of the west- 
ern coast of Great Britain, and bave been noticed by 
some of the earlier English writers as a Turbo. I have 
not, however, been able to find any such description. 
Several of the specimens of this shell, taken from the 
fishes, crawled about upon being placed in clear water ; 
proving that they must have been swallowed very re- 
cently, and of course not far from our shores. 
OxiNoE ? GLABRA. 
O. testa ovali, parva, ventricosà, sub-umbilicata, alba, fragili, spirà 
brevi, laterali, labro integro, columellà arcuatà, apertura valdé effusá. 
Diam. of axis six twentieths, transverse diam. eight 
twentieths of an inch. 
Habitat Mass. Bay. 
Cabinet of Bost. Soc. Nat. History. 
Description. Shell small, oval, ventricose, thin, dia- : 
phanous, smooth, white and shining; spire very short, 
lateral, and visible internally ; volutions two, the last 
