ON SOUTH AFRICAN ENNE^. 57 



are most finely, delicately, closely and regularly rib-striate ; 

 while Sylvia is nearly smooth, except for a few irregularly 

 dispersed striae, all over except on the last half -whorl, where 

 the stride become more regular and more clearly defined. The 

 aperture is smaller, and the peristome much less thickened 

 and expanded in m el villi than in sylvia, and the parietal 

 plait is larger and more pi'ominent, the labral tooth smaller 

 and less distinctly divided, the " tooth " or swelling on the 

 columellar lip is less angular, and the internal columellar fold 

 is of quite a different nature, being simple instead of crossed 

 by an oblique strengthening rib as in sylvia. The profile of 

 the outer lip, too, is much more sinuous in mel villi. 



The specimen with the abnormal height of 2"6 mm. is no 

 wider than the type, has fully 7 whorls and has the peristome 

 scarcely thickened, leaving the sAvelling of the columellar lip 

 undeveloped ; the internal columellar fold is small. 



Ennea columnella 31. & P. (PI. Y, fig. 47), is found in 

 company with this species at Karkloof, Dargle, and Edendale, 

 and, both being much of the same size, a critical comparison 

 may here be convenient. 



The form of columnella is rather wider and less fusiform; 

 the surface is almost smooth, except immediately below the 

 suture, where irregular microscopic striation may be detected 

 in a few places, and on the last half-whorl where somewhat 

 regular striation appears ; the parietal plait is narrower, the 

 labral tooth more widely bifurcate, the basal tooth smaller 

 and more central, the slight ridge across the base of mel villi 

 is absent, and the columellar plait is of quite different con- 

 struction (see postea, p. 58). With the assistance of a 

 moderately powerful hand-lens their separation is quite easy. 



I have pleasure in dedicating the species to Dr. J. Cosmo 

 Melvill, who has done so much towards the elucidation of 

 the South African non -marine molluscan fauna. 



This is the form referred to by Connolly ^ as examples 

 from Natal, distinct from E. sylvia, whose habitat is Mae- 

 strom Forest, Bedford, Cape of Good Hope. 



• Ibid., p. 86. 



