588 ^ NOMENCLATURE AND DISTRIBUTION OF TIIE GENUS PYTHIA, 



M. 



peritreme sharp and straight or expanded, thickened, often toothed 

 or transversely ribbed." 



And has established the following division of the Family : 



Family AURICULACFA, Blainville. 



1st Sub-Family Otinea. 



Which is divided into two genera. 



A. Otina, Gray. 



B. Camptonyx, Benson. 



2nd Sub-Family Melampea. 

 Is divided into three genera. 



C. Melampus, Ifontford. 

 B. Marinula, King. 



E. Pedipes, Adanson. 



Zrd Sub-Family Auriculea. 

 Is divided into nine genera. 



F. Pythia, Bolton, the genus now under consideration. 



G. Plecotrema, BT. and A. Adams. 



H. Cassidula, Ferussac. 



I. Auriculus, Montfort. 



K. Alexia, Leach. 



L. Blauneria, Shuttletvorth. 



If. Luconia, Gray. 



iV. Coilostele, Benson. 



0. Carychium, 0. F. Mutter. 



The genus Pythia was defined by Pfeiffer in 1856 in hisMono- 

 graphia Auriculaceorum Viventium as follows — " Shell depressed 

 ovate ; whorls provided on both sides with varices, forming a 

 more or less distinct zigzag streak on the compressed sides ; 

 aperture externally wide, narrowed within by a strong collumellar, 

 and several strong parietal plaits ; right margin of the peristome 

 furnished within with an oblique dentiferous callus, which usually 

 appears externally." 



