OLIVID^. 1Y5 



Distr. — 55 sp. Subtropical ; East and West America, W. 

 Africa, India, China, Polynesia. Fossil. Eocene — . O. erythro- 

 stoma^ Lam. (Ivi, 67). 



Shell oblong, subcylindrical, polished ; spire short, conic ; 

 suture canaliculated ; aperture long and narrow, anteriorly widely 

 notched ; columella obliquely plicate, sulcate or striate in front, 

 posteriorly callous ; outer lip simple. 



Animal with tentacles enlarged at the base ; mantle with a 

 posterior filament lodged in the channeled suture of the spire ; 

 foot long and acuminate behind, shield with the side-lobes taper- 

 ing, acute, small. 



Operculum none, in the restricted group. 



Like most shells enveloped in the voluminous foot of the 

 animal, Oliva has no epidermis. The shell has an under layer 

 with different pattern of coloring, but this is never exposed 

 except in worn specimens, or else artificially by the aid of acids : 

 heUce it is evident that unlike the Cypraea, which changes its 

 pattern upon becoming mature, the two layers of Oliva are 

 simultaneously produced at all stages of its growth. The interior 

 volutions are often absorbed till they become of paper-like 

 tenuity in order to accommodate the increasing bulk of the 

 animal. 



LAMPRODOMA, SM^aiusou. (Ramola, Gray.) Spire acuminate, 

 elevated, suture canaliculated ; inner lip simple posteriorly, but 

 regularl}^, numerously plicate anteriorlj^ the plicae more trans- 

 verse than in the typical group. 0. volutella (Ivi, 68 — the only 

 species ) is found in vast numbers OA^er many acres on the sandy 

 beach west of the city of Panama. Some time after the retreat 

 of the tide, it is found crawling about with much vivacit}^ on 

 the wet sand. The shell, while the animal is moving, is wholly 

 covered with the foot-lobes, and these are entii'ely concealed 

 with a thick coat of sand. When the first wave of the returning 

 tide strikes them, washing ofl^ this coating, they instantly bury 

 themselves. 



CALLiANAX, H. and A. Adams. (Scaphula, Gray.) Shell swollen, 

 ovate, with short conical spire and channeled sutures ; aperture 

 wide, efl^'use in front ; inner lip with a very thick, defined callus, 

 and a few frequentlj^ indistinct anterior plaits. 2 sp. W. Coast 

 of America, Patagonia. 0. hiplicata^ Sowb. (Ivi, 69). 



AGARONiA, Gray. (Tortoliva, Conr. Hiatula, Swains.) Shell 

 thin, oliviform, but a little effuse anteriorly ; spire acuminate ; 

 aperture rather wide, effuse below ; columella not thickened 

 posteriorly, tumid, with a few oblique plaits in front. Has a 

 small operculum. 0. hiatula, Lam. (Ivi, 70). 



OLIVANCILLARIA, d'Orb. (Utriculina, Gray. Lintricula, H. 

 and A. Adams. Scaphula, Swains. Anazola and Claneophila, 

 Gray.) Shell smooth, wide, oblong, last whorl swollen ; spire 



