OP CONCHOLOGY. 73 



Atys costulosa, Pease. 



T. elongata, subcylindrica, postice angustiore, alba, umbilicata, 

 longitudinaliter costata, postice etantice striis elevatis decussata; 

 labro postice valde tortuoso et producto ; columella ad basin 

 eversa, planulata, appressa ; apertura angusta. 



Long. 5^. Diam. 2| mill. 



Hah. Insl. Oabu. 



Shell elongate, subcylindrical, narrowest posteriorly, white, 

 umbilicate, longitudinally ribbed, crossed at either end by ele- 

 vated strise, which become more remote towards the middle of 

 the shell, and gradually vanish ; outer lip posteriorly strongly 

 twisted and produced ; columella everted at base, flattened and 

 appressed ; aperture narrow. 



I have met with but a single specimen of this interesting spe- 

 cies, the sculpture of which is so distinct that it cannot be con- 

 founded with any heretofore described. 



Pachypoma virescens, Pease. Plate viii, fig. 10. 



T. conoidalis, imperforata, medio vix tumida ; anfr. superne 

 concavis, oblique, rude, irregulariter rugoso-plicatis, infra ad 

 marginem biseriatim squamatis, squamis nodosis, contiguis, 

 rugosis ; suture linearis, undulata ; anfr. superioribus profunde 

 foveolatis ; anfr. ultimo ad peripheriam acute angulato ; basin 

 planulata, conferte squamato-lirata ; apertura obliqua, ovaiis, 

 interior margaritacea ; columella antice tuberculoso dentata ; 

 viridescens, squamis, lirisque albidis, columella cosrulea cir- 

 cumdata. 



Alt. 25. Diam. 25 mill. 



Ha^i. Insl. Tarawa. 



Shell conoidal, imperforate, slightly swollen at the middle ; 

 whorls concave on their upper part, obliquely, rudely, and 

 irregularly rugosely plicate ; the lower margin of the whorls 

 encircled by two rows of nodose scales, scales contiguous and 

 rough ; suture linear and undulate ; upper whorls deeply pitted ; 

 last whorl acutely angulate at its periphery ; base planulate, 

 encircled with nine contiguous squamose ridges, unequal in size ; 

 aperture oblique, oval, interior pearly ; columella callosity ter- 

 minating in a tubercular tooth ; greenish, scales and ridges 

 whitish, encircled by a blue line. 



The above species is common at certain localities in Polyne- 

 sia, but invariably thickly coated with lime, except occasionally 

 the young. It was referred several years since, by the late H. 

 Cuming, to T. confragosus, Gld. Later, however, it was iden- 



