OF CONCHOLOGY. 101 



on the middle portion of the whorl, longitudinally roughened 

 occasionally by longitudinal stride ; columella furnished with 

 three plaits, the lower one near the base, slightly oblique, pass- 

 ing over the columella and joining the lip ; upper plaits trans- 

 verse ; outer lip bilaminate on the middle. 



Remark. — Its nearest ally is M. granifer, Mouss. 



Laimadonta conica, Pease. — Plate 12, fig 15. (Proc. Zool. 

 Soc. London, 1862.) 

 Description. — T. elongato vel ovato-conica, solida, transversim 

 tenuiter striata, striis longitudinalibus obsolete granulata ; anfr. 

 plano-convexis, superne prope suturam vix depressis; spira acuta, 

 interdum elongata ; sutura linearis ; apertura auriculata ; plicte 

 parietales 2, parallels, magnis, plica columellaris vix obliqua ; 

 perist acutum, margine dextro intus unilamellato, ad basim callo 

 interno incrassato. Gastaneo-fusca, fascia albida cingulata. 



Dimensions. — Long. 7, diam. 3 mill. 



Hah. — Paumotus. 



Shell elongate or ovate conic ; solid, transversely finely striate, 

 rendered somewhat granulose by irregular longitudinal striae ; 

 whorls flatly convex, somewhat depressed beneath the sutures ; 

 spire acute, sometimes elongate ; suture linear ; aperture auricu- 

 late, straight, compressed posteriorly ; plaits on the walls of the 

 aperture two, large and parallel, plait at base of columella 

 smaller and slightly oblique ; outer lip simple, thin, furnished 

 with one transverse lamella, base encircled with an internal cal- 

 losity, connecting the columella and the lamina. Color chestnut 

 brown, encircled by one, very seldom two, whitish bands. 



Remarks. — The above species was originally described from 

 specimens received from the Central Pacific. Since then it has 

 been found at the Paumotus. Although the latter are twice the 

 size of the former, and much more elongate in shape, 1 cannot 

 discover that they are entitled to rank as separate species. 



Planaxis abbreviata, Pease. — Plate 12, fig 16. (Proc Zool. 

 Soc. London, 1865.) 



Description. — T. ovata, solida, purpureo nigrescente, intus 

 purpurea ; spira brevi, acuta ; suturis beme impressis ; anfr. 5, 

 convexis, spiraliter striatis, striis interdum in medio anfr. ultime 

 evanescentibus ; apertura ovata, superne sulcata ; labro margine 

 interno crenulato ; labio superne calloso, laevi ; canali brevissima; 

 basi spiraliter sulcata. 



Dimensions. — Long. 10, diam. 6 mill. 



Hal.— Tahiti. 



