•ROCKlCDINfiS OF THE M ALACOLOC.ICAL SOCIKTY. 



ON A SMALL COLLECTION OF LAND AND FRESH-WATER SHELLS 

 FROM UGANDA, WITH DESCRIPTIONS OF A NEW SRECIES 

 OF MAUTENSIA AND TWO NEW SPECIES OF LIMICOLARIA. 



By n. B. Preston, F.Z.S. 



Ilead^th M(trch, 1906. 



The sppcimcns which form the subject of the present pnper were 

 phxced in my hands for identification by Mr. J. H. Pousonby, 

 and include the following genera : Marlei/sia, Achat iv a, Limicolnria, 

 Snccinea, and Ampullaria. As might easily be expected in a collection 

 from Central Africa, the LimicolaricB largely predominate ; many of 

 these appear to be varietal forms of already known species, though 

 there are two which I am unable to identify, and these I now venture 

 to describe in the present paper. 



Martensia BowKEH.ii, n sp. 



Shell thin, depressed, perforate, keeled at the periphery, dull 

 brownish grey, ornamented at the sutures and periphery with 

 a chocolate-coloured band ; whorls 5-6, sculptured with very fine 



transverse strijB and coarser lines of growth ; base of shell somewhat 

 polished and sculptured with fine wavy spiral striae ; sutures impressed; 

 aperture obliiiuely lunate ; peristome simple ; columella descending 

 obliquely, and somewhat reflexed over the rather narrow umbilicus. 

 Diam. maj. 17-5, alt. 8-75 mm. ; aperture, diam. 8, alt. 7 mm, 



Ilah. — Uganda district. 



This species may be compared with M. permanem,^ Smith, also from 



Jouiu. Malac, 1901, vol. viii, p. 9-1, tii. 



