119 



DESCRIPTION OF A NEW RISSOID SHELL FROM 

 SOUTH AFRICA. 



By J. R. LE B. TOMLIN, M.A. 

 (Read before the Society Sept. 13th, 1916). 



Microsetia durbanensis n.sp. 



Shell minute, ovate-conical, narrowly perforate, rather opaque, 

 smooth, white or yellowish-white ; the upper whorls with the excep- 

 tion of the protoconch are frequently reddish-yellow, while the two 

 last whorls are white j protoconch dull vitreous, rather obtuse ; 



Microsetia durbanensis n.sp. 



whorls about six in number, convex, and separated by a rather 

 deeply-channelled suture; aperture oval or somewhat pear-shaped, not 

 quite half the total length of the shell ; peristome continuous, acute, 

 not thickened ; columella nearly straight and strongly callous over 

 the umbilical perforation ; operculum unknown. 



Length, 2*4 mm. ; diam. max., i'5 mm. 



Habitat : Durban, whence Mr. H. C. Burnup has sent numerous 

 examples. 



The type specimen figured has been deposited in the British 

 Museum. 



Unfortunately all the specimens collected so far have been dead 

 ones. The surface of the shell seems very liable to corrode. 



This species doubtless belongs to the same group as Microsetia 

 halia Bartsch and M. Siisna Bartsch. 



