60 



clivibus muoita: apertura obliquissima. Axis *fe, diam. j poll. 

 Hab. Sandwich Islands. 



I have met with no description of a species so small as this, 

 and yet its characters are very prominent. Its form and concen- 

 tric ridges give it the aspect of a conical operculum. 



Planaxis lineolatus. Testa minuta, solida, acuto-conica, 

 ex albido fuscescens, lineis castaneis numerosis cincta: spira 

 acuta, anfr. 6-8 planulatis, supernis granulatis, ultimo ^ testse 

 longitud. pequante, ad peripheriam sub-angulato : basis spiraliter 

 striata: apertura rotundato-ovata, postice haud callifera; labro 

 pallido,vel i'usco tessellato, intus denticulato; fauce fusco. Axis £, 

 diam. £ poll. Hab. Wilson's Island. 



This little shell is not infrequent in cabinets, but I find no de- 

 scription of it. 



Pyrajiidella ambigua. Testa minuta. albida, imperforata, 

 ovato-subulata, costis longitudinalibus exilibus ad 20 ornata, inter- 

 vals spiraliter striatis : spira acuta, anfr. ad 10 planulatis : aper- 

 tura auriculata, antice subeffusa ; columella callosa, gibbosa, an- 

 tice sinuata ; labro simplici, incrassato. Axis {- ; diam. T V poll. 

 Hab. Clermont Tonnere Island. 



The characters of this little shell, which I have for the present 

 placed under Pyramidella, are somewhat abnormal. Its size and 

 sculpture would suggest Truncatella ; its aperture is somewhat 

 like the effuse form of Eulima ; the form of aperture is a'so like 

 Pyramidella, though it has no proper plaits, but merely an intru- 

 sion of callus with an adjacent sinus in place of them, and in 

 this, is like Monotigma. 



Cerithium (Potamis) sacratum. Testa rudis, elongata, badia 

 et fascia lutea cincta : spira turrita, anfr. ad 10 convexis, vix 

 angulatis, et liris obsoletis cinctis, supernis plicatis, ultimo glo- 

 boso, abnormali, varice magno munito ; sutura profunda, lutea : 

 apertura rotundata, antice effusa, haud emarginata ; labro everso, 

 polito, piceo: operculum multispirale. Long. 1^; lat. f poll. 

 Hab. Sacramento River, California. 



Allied to C. varicosum, Sowb. The surface, though not 

 smooth, is destitute of longitudinal ribs except near the tip ; it 

 has also a pale sutural region and a less marked canal. 



