KELLIA. 85 



posed is a natural one, and Philippi, unacquainted with 

 Tin-ton's genus, framed his Bornia for the same assem- 

 blage of species. When two naturalists, working apart, 

 constitute generic groups of equal limitation, there is a 

 strong presumption in favour of the naturalness of the sec- 

 tions proposed. 



Recently, however, M. Recluz has proposed the generic 

 separation of the two shells mentioned, and regards them 

 as the types of different genera. Convinced that the Poron 

 of Adanson, somewhat indistinctly described and figured 

 by that celebrated naturalist, is a near ally of the Kellia 

 rubra (a conclusion to which he has been led by an exami- 

 nation of the Senegal shells in the collection of M. Petit) ; 

 he constitutes a genus Poronia for these shells, founding it 

 chiefly in minute peculiarities of the hinge.* These differ- 

 ences seem, he remarks, in a tone of censure, to have 

 escaped Fleming and Macgillivray, who have not, however, 

 in their descriptions, committed the very unscientific mis- 

 take of uniting an animal with two separated siphons to a 

 shell presenting an entire pallial impression. We are inclined 

 ourselves to regard such minute variations of hinge and 

 ligament, as of little value in this family — a view we take, 

 in common with two most sound authorities, Loven and 

 Alder. The latter malacologist, has, however, discovered 

 a feature in the animal of Kellia rubra, so peculiar, when 



* The generic character given by M. Recluz, runs as follows : — " Testa ovata 

 seu subrotunda, rcgularis, transversalis, requivalvis, inaequilatera, clausa. Apices 

 nrinuti, antice recurvati. Lunula areaque nulla;. Cardo dentibus cardinalibus 

 duobus in utraque valvula, apicali minima ante auctam (?), antica majori apicalem 

 approximata, transversali, concava, ad marginem superam inflexa et in valvula 

 dextra inserta ; fossula interposita, elongata, oblique valde transversali, sub 

 dente laterali decurrente, ligamentum magnum, cartilagineum, unicum ferente ; 

 dente laterali unica, postica, remota, in valvula sinistra triangularis, in dextra 

 inserta. Impressiones musculares ovales, aaquales. Sinus palliaris nullus. 



" Animal fere ignotum, pallio posticc bilobo ; siphonibus duobus, disjunctis ; 

 pede piano, acuto." — Recluz, Revue Zoologique, June, 1843. 



