130 
MOLLUSCOUS ANIMALS. 
The shell is more than half immersed in the middle of the foot, and it is this immersion which causes it 
to have the polished coat. Most of the large species have no operculum, but the smaller species often have 
an oblong, horny one, which is nearly as long as their mouth ; this is particularly the case with O. zonalis, 
O. semistriata, O. conoidalis, where the operculum is bright sea green. 
The olives live buried in the sand, and are generally taken by fishing for them with lines baited with 
flesh. According to M. Quoy, these animals are exceedingly active, and they have the power of regaining 
their proper position even when they are laid upon their backs. 
The inner whorls are absorbed exactly as in the Cones. The pillar is very tortuous and thin; and the 
apex is filled inside with a glossy deposit. 
The distinction of the species of the olives is attended with very great difficulty. It appears that Linneeus 
made too few, and that Lamarck and succeeding authors have gone to the other extreme and made too many. 
Their arrangement might be facilitated by dividing them into sections, thus, 
They have all a belt in front of the last whorl over the canal. Some have a second belt behind this, as 
O. utriculus, O. clavula, O. gracilis, O. undatella, O. acuminata, O. subulata, and O. leucozonias. But most 
are without this belt. Most of them have the inner lip even, as O. porphyria, O. semistriata, 0. Brasiliensis, 
&c. But some have two callosities on their lip as O. undatella, and its variety O.bifasciata. 
The operculum of O. eburnea is green when fresh, it is ovate, lanceolate, and with the nucleus very slightly 
curved and spiral, so that it very nearly resembles the operculum of a Littorina, but the nucleus is not spiral. 
The scar of attachment for a band nearly the shape of the operculum but half its breadth is along the straight 
side. 
Oliva gracilis, t. 36. /. 21. — Brocl & Sow. Zool. Jour. iv. 379. 
Shell oblong, subcylindrical, white, varies in the irregular brown spots near the suture, and near the 
anterior belt of the last whorl. Spire conical, convex; suture distinct; anterior belt about one-third the 
breadth of the last whorl, marked with a spiral groove on its hinder margin. Mouth lanceolate, wide in front, 
with eight ornineobscure folds, innerlip thickened, and the callosity behind extending to the last whorl but 
one. Axis 8f ; diam. 3; mouth 5 lines. 
Differs from 0. nivalis in its colour and in the belt being divided into two by a groove. 
Oliva leucozonias. t. 36./. 24. 
Shell ovate, fusiform, slender, polished, pale brown, dotted with a white spiral band near the suture and 
the back edge of the hinder anterior belt. Belt and suture black spotted; spire acute, half as long as the 
mouth. Mouth narrow, pillar obliquely plaited, front of pillar callous. Axis | inch. 
Inhab. 
Oliva semistriata. t. 36./. 10. 
Shell ovate, lanceolate, bluish grey ; spire conical, acute, rather produced, smooth, with an obscure band 
near the suture ; last whorl closely concentrically striated on the hinder half, with a white central band ; 
anterior belt, narrow, white. Mouth lanceolate ; outer lip expanded in front ; inner lip callous, extending up 
to the upper suture, with an obscure oblique fold, producing a single protuberance in front; canal wide; 
throat black ; operculum horny, lanceolate. Axis 9 ; diam. ; mouth 6 lines. 
Var. 2. lutea. 
Shell yellow-brown, with a whitish band near the suture, and another in the centre of the last whorl not 
so distinctly lined near the suture. 
