373 

 MONOGRAPH OF THE GENUS 



MARGINELLA. 



By G. B. Sowerby, Jun. F.L.S. 



Char. Gen. Testa subovata, nitida ; spira brevi, obtustl, nonnun- 

 quam occulta. Apertura elougata, autice plerumque emarginata ; 

 columella nonnuuquam callosa, plicata; labio externo reflexo, 

 plerumque incrassato ; operculum uuUum. 



Shell oval, smooth. Spire short, obtuse, sometimes liidden by 

 the deposition of enamel, or included in the last whorl. Aperture 

 long, generally emarginated at the anterior extremity ; columellar 

 lip sometimes thickened at both extremities, with folds increasing 

 in obliquity and length towards the anterior termination, but not 

 so much so as in Valuta ; outer lip reflected and generally thickened 

 so as to form a varix ; no operciilum ; no epidermis. 



The shell being almost enveloped by the mantle, has a brilliancy 

 of pohsh equal to the Cowries. This, and the reflected edge of the 

 outer lip, sufficiently distinguish all the species from the genus 

 Voliita. 



_ 1. Mahginella Eaba (pi. Ixxiv. f. 1, 2.), Linn. Syst. Nat. M. 

 bifasciata var., La7n. Anim. s. vert. vii. p. 357. 



M. ovata, griseo-fnlva, punctorum magnorum seriebus irregula- 

 ribus 7 ad 9 sparsun cincta; spira prominula; anfractibus vix 

 angulatis, ad angulum crenulatis ; columeUa quadriphcata, labio 

 externo crasso, paululum arcuato, plerumque minute subcrenulato, 

 postice subemarginato, antice attenuato, emarginato. 



Oval, greyish buff, with 7 to 9 rows of distant large spots ; spire 

 rather prominent; whorls very slightly angulated, crenulated; 

 columella with four folds ; outer lip slightly bowed, very lightly and 

 minutely crenulated, emarginated at the base. 



There is no doubt of this being the true Voluta Faba of Linnaeus; 

 from Senegal. 



2h 



