122 



position is doubtful, for the aperture has hardly that 

 thickening which we observe generally in the genus. Its 

 appearance is not unlike some species of Ammonites. 



Crossea cancellata. n.s. T. minuta, alba, nitente, tiirUnata ; 

 anfr. 3, carinis parvis crebris etstriis obliquiis tenuissi'vds pulcherrime 

 cancellata, ap'ce loioi, peUucido, apertura circulari, antice et postice 

 conspicue canaliculata, labio simplice, basi chkobus sulcis unolato altera 

 angusto et in medio eorum costa spirali prope columellam insignlta. 



A minute white shining turbinated shell of three whorls 

 which are beautifully cancellated by close spiral ribs and 

 distinct oblique striae. The apex is smooth. The aperture 

 is circular and channelled above and below. Behind the 

 inner lip there is a narrow groove forming a false umbilicus, 

 then a rounded spiral rib, and then a broad regularly striate 

 groove on the base. Diam'. scarcely li mil. Blackman's 

 Bay. W. F. Petterd- 



This minute and very beautiful species adds a fifth to the 

 genus whose synopsis is as follows : — 

 Shell, varicose. C. mircnuki. Jai)an. 



, outer lip, thin. beUvlus. Japan. 



, small, whorls shining and pimctate. concinna. 



Port Jackson, 

 , somewhat smaller, outer lip fimbriate. labiata. 



Long Bay, Tasmania. 

 — — , minute, shell cancellate. cancellata. Blackman's 



Bay, Tasmania. 



Marginella cypr^oides. T. parva, ovata, cyprceformi, alba, 

 opaca loivi, spira omnino occulta, labro nivea marginato incrassatOj 

 postice producto; apertura regulariter arcuata, angusta, columella 

 nivea encausta, ad basim crebre 4 pUcata. Long. 6, lat. 4 mil. 

 Blackman's Bay. W. F. Petterd. 



^ Tasmania is already rich in this genus, but this species 

 differs from all in being quite smooth and having the spire 

 quite hidden by the produced and thickened outer lip. From 

 above it appears like a Cyprea. It comes nearest to Marginella 

 volutiformis, but is much smaller and destitute of plaits. 



RissoA ANGELi (miM) vide Proc. 187C. I find that this shell 

 varies considerably. Sometimes the ribs a very prominent and 

 variciform, and sometimes they are fine and close and scarcely pass 

 to the last whorl, the spiral lira?, which are beautifully delicate, 

 the rounded aperture and umbihcus are constant features. Some 

 authors would place the species in the genus Cyclostrema. It is 

 very minute. Blackman's Bay. W. F. Petterd. 



PissoiNA MimiTissiMA. T. minuta, pyramidata, polita, luteo 

 albida, apice livida, basi pallidisime lutea fasciata ; anfr. 5 omnino 

 Icevibus, et politis, tenue convexis ; labro acuto, producto, labio refiexo ; 

 apertura late elliptica antice et postice canaliculata; apice obtuso. 

 Long. 11 ; lat. | mil. 



A minute JRissoina destitute of ornament of any kind and 



