ON AFRODONTA MELV. AND PONS. 337 



tenui, tribus lamellis plicive prasdito^ altera obscura ad 

 basin, interdum incrassata, extensa, interdum dentiformi, 

 altera collumellarein apud marginem medium, loiige intrante, 

 tertia interna, incrassata, contra aperturam extensa. 

 "Alt. 0-80, diam. 1-39 mm. 



"Hab.— Dargle, Natal, January, 1907 (H. C. Burnup)." 

 Again, in the description of this species, reference is made 

 to a columellar lamella or plait, which would be better 

 described as about the middle of the parietal wall. In 

 pointing out the chief distinction between the two species, 

 bilamellaris and trilamellaris, the authors omit a 

 character by which the shells may be distinguished in the 

 field without the aid of a lens: bilamellaris is openly 

 umbilicate (fig. 18), about proportionately with the three 

 new species described hereunder (figs. 10, 13, 17), while 

 trilamellaris is widely excavated, even in excess of perf ida 

 (fig. 4). 



Endodonta [Endodonta (Afrodonta)] 'peviida '}i. name. 

 PI. XXIV, figs. 1-6. 



Trachycystis rotula Melv. & Pons., Ann. and Mag. Nat. Hist., 



vol. xix (1907), p. 99, pi. 

 vi, figs. 12, 12a ; ibid., vol. 

 i (1908), p. 135. 



Shell minute, subdiscoidal, deeply and widely excavated, 

 horn-colour, thin, translucent ; whorls 5, narrow, convex, 

 the last rounded at the pei'iphery, deeply impressed at the 

 sutures, very closely microscopically lirate except the first H, 

 which are smooth ; aperture nearly erect, broadly crescentic, 

 with thin peristome slightly thickened towards the colum- 

 ella, and furnished with the following internal, deep-set, 

 strong lamellte or folds : (a) One on the basal wall, whitish, 

 set back from the peristome about one-fifth of the last whorl, 

 and in-running for about one-fourth of the whorl : (b) one 

 on the outer wall, also whitish, squarish and very strong, 

 about the same length, and set back nearly as far from the 



