ON SOUTH AFIJICAX ENNE.E. 79 



deep-seated coluniellar plait, but little thickened on the 

 lower edge and slightly drawn forward on the right, and a 

 swelling on the coluniellar lip. 



Height 2-91, width 1-33 mm. 



Hab. — Gowie's Kloof, Grahamstown, Cape of (xood Hope 

 (Farquhar). 



All the specimens that I have seen, namely five in my own 

 collection, received from Mr. Farquhar, nine in Mr. Ponsonby\s 

 collection, and a large sei-ies in the Alexander McGregor 

 ^luseum, Kimberley, come from the same locality, and are 

 most constant in detail, varying slightly only in size, relative 

 width, and in the number of whorls {oh to 6j). 



The following are the dimensions of such examples as I 

 have measured, in addition to the type, and fairly repre- 

 sent the extent of variation observed : Height x width, 

 3-20 X 1-37, 2-94 x 1-37, 2-88 x 1-31, 272 x 1-30, 2-66 x 1-.33 mm. 



A curious feature in this species is the position of the 

 smooth area on the body-whorl. In many, if not most, striate 

 Enneffi, there is such an area distinct from the callus, more 

 or less smooth, immediately above the aperture, in which 

 position it is easily conceived to be formed by the constant 

 passage of the mantle over the spot while the mollusc is 

 active. In by far the greater number of the specimens of 

 this species examined, the centre of the smooth area is 

 considerably to the left of the aperture, though in a few its 

 position is normal. It is difficult to understand why it 

 should generally be so far misplaced, unless the animal 

 possess some peculiar development of the mantle. 



This species has been tentatively identified as Ennea dar- 

 glensis M. & P., and distributed as such ; but the differences 

 are so many and so great that the two species cannot be 

 considered as closely akin ; a mere glance at the figures of 

 the two species should be enough to bring conviction as to 

 their wide distinction. 



The general arrangement of the processes of the aperture 

 is somewhat similar to that of E. m on tana M. & P., but 

 the shorter, stouter form Avith fewer whorls, the continuous 



