ON SOUTH AFIUOAN ENNE^. 47 



with more superficial, undivided labral process, and columellar 

 tooth less developed so showing more of the deep-seated colu- 

 mellar plait behind it. From the variety berthse it is 

 separable by its more slender, cylindrical form, narrower 

 columellar lip with more open aperture and solid, nearly 

 superficial labral tooth, and generally the absence of striation, 

 or Avhen it is present above the last half -whorl, its extreme 

 shortness. 



The twenty-five specimens collected in Durban, one of 

 which is shown in fig. 31, and two of those found in Maritz- 

 burg, are sculptured immediately below the suture with more 

 or less regular, rather coarse, typical striation, which, how- 

 ever, soon disappears, leaving the remainder of the whorls 

 almost smooth, except the last half-whorl, Avhich is sculptured 

 all over. With the presence of this infrasutural striation 

 occurs a slight increase in width ; otherwise the shells agree 

 in all respects Avitli the smoother shells from Maritzburg and 

 those from Pinetown and Nottingham Road, 



There is considerable variation in the height of individuals 

 of this variety, though not much in width unless accompanied 

 by the variation in sculpture ; with an increase in height there 

 seems to be invariably also an increase in the number of 

 whorls : thus, the specimens that I have examined vary from 

 2'74 mm. to 3*51 in height, and the number of whorls from 

 5i to 7. 



The following dimensions show very fairly the extent to 

 which the variety, so far as is yet known, differs in size and 

 proportion in various individuals : 



The smoother form : 



Maritzburg : 3-32 x 1-27, 3*10 x 1-28, 2-77 x 1-31 mm. 



Pinetown : 3*41 x 1-33, 2-74 x 1-33 mm. 



Nottingham Road : 2-85 x 1*32 mm. 



The form with infrasutural sculpture : 



Durban : 3-51 x 1*45, 3*30 x 1-45 (fig. 31), 3-02 x 1-45 mm. 



Maritzburg : 3-37 x 1-45, 3*33 x 1-47 mm. 



These dimensions, which are chosen to include the most 

 divergent forms of the shells examined, Avell show the re- 



