1 1() ]\Ir. I\I. Connolly on non-marine Mollusca 



Sitnla diaphana, sp. n. 



Shell small, imj)erforate, globose-conic, very tliiii, trans- 

 parent, smooth, shining, pale yellow-corneous. Spire 

 somewhat elevated, sides regular, meeting at an angle of 

 about 80°; apex pointed. Whorls 5, rapidly increasing, 

 rounded, with very slight peripheral carination ; covered on 

 both sides and almost to the apex with very faint, irregular, 

 straight, transverse striae, which are only visil)le under a 

 lens, and microscopic, close, spiral strije, allowing the sur- 

 face to appear smooth and polished to the naked eye; suture 

 simple, well defined. Aperture rounded-lunate ; peristome 

 simple, acute ; columella short and straight, upper margin 

 very narrowly, solidly reflexed ; callus none. 



Diam. maj. 4"2, min. 3'8 ; alt. 40 ; apert., alt. 2*0, lat. 

 2-2 mm. 



Type-locality. District north of Macequece (JB. Cressy). 



Tracfiycystis avibiyua, sp. n. 



Shell small, rimate, subconic-globose, very thin, trans- 

 lucent, rather dull, carneo-corneous. Spire a little elevated, 

 apical angle about 95° ; apex pointed. Whorls 5, rounded, 

 with faint peripheral carination, rapidly increasing, the 

 apical smoothly punctate, remainder covered on both sides 

 with extremely close, straight, transverse, microscopic striae, 

 with spiral sculpture commencing on the 4th and stronger, 

 crossing the transverse striae, on the oth whorl ; suture 

 simple, moderately impressed. Aperture nearly semi-lunar ; 

 peristome simple, acute ; columella very short, margin very 

 narrowly reflexed, but almost covering the minute rima. 



Diam. maj. 4"5, min. 4"0; alt. 3*7; apert., alt. 2*5, lat. 

 2*1 mm. 



Type-locality. Head-waters of R. Inyamkarrara, 4500 ft. 

 {B. (Jressy). 



Irachcystis sericea, sp. n. 



Shell small, umbilicate, subglobose, rather thin, trans- 

 lucent, dark reddish corneous with a silky sheen. Spire 

 slightly raised, apex bluntly rounded. Whorls 5, very 

 ronnd, rather gradually increasing, the apical half-whorl 

 smooth, remainder prettily sculptured with very close, 

 slightly curved, regular, prominent, transverse striae, clearly 

 visible without a lens, between each of which are 3 or 4 

 microscoi>ic transverse striae, the whole imparting a silky 



