219 

 MONODONTA. 



TUHBO PAGODUS. TROCHUS LABIO, LillH. 



Chemnitz, 5, tab. l66,fig. 1579, 1580. 



This genus occupies, as it were, an intermediate space 

 between the Trochus and the Turbo, distinguished 

 from the former by the aperture being rounder, and 

 scarcely at all depressed, and from the latter by the 

 tooth-like projecting angle which the truncated colu- 

 mella occasions at the base of the aperture. Shell oval 

 or conoid; aperture entire, rounded; the margin dis- 

 united at the upper part, and closed by an operculum ; 

 the interior margin in some appearing double, or 

 grooved in its thickness, in others single and sharp: co- 

 lumella arched, truncated at the base, exterior surface 

 occasionally tuberculated or striated. 



Monodonta bicolor Monodonta tectum 



pagodus [cum labio 



tectum Persi australis 



papillosa • - • - canalifera 



coronaria viridis 



^Egyptiaca fragarioides 



carchedonius ■ constricta 



• modulus tricarinata 



» 



