Freshwater- Shells from Central Africa. 153 



Hah. Usagara {Bishop Hannington). 



Of five specimens of this species all have a slender band or 

 line at the periphery and another, sometimes a little broader, 

 somewhat lower down. Thej all also exhibit a somewhat 

 pellucid or brownish zone around the umbilicus. A line which 

 passes round the middle "of the fourth whorl is sometimes 

 continued on the fifth and last ; this line in two examples is 

 interrupted, thus forming a transverse series of elongate dots. 

 A single example is irregularly marked with brown at the 

 lower part of the body-whorl and has a second interrupted 

 line just above the peripherial zone. The dark scattered 

 dots are few and irregular. Owing to the thinness of the 

 shell the markings are as vivid within the aperture as upon 

 the exterior. There is only the feeblest trace of spiral stria- 

 tion. B. nignlineaius from Madagascar is very like this 

 species in form, but exhibits more distinct spiral striation, 

 has a narrower perforation, is more numerously banded, its 

 general tint more yellow, and not sparsely dotted. B. trutta^ 

 Blanford, an Indian form, is also very closely related. 



Bulimus [Rhachis) quadr icing ulatus. (PI. V. fig. 6.) 



Testa oblonga, subturrita, perforata, tenuis, nitida, ilavo-Iactea, ad 

 apicem purpurea, lineis saturate fuscis (in anfr. ultimo quatuor, 

 in superioribus tribus) cincta ; anfr. 6|, perconvexi, regulariter 

 sublente acerescentes, iucrementi lineis tcnuibus obliquis, striisque 

 spiralibus confertis exilissimis sculpti, ultimus zona subpellucida 

 circa umbilicum, strigisque obliquis paucis subhyalinis hie iUic 

 ornatus ; peristoma tenue, ad insertionem columellse breviter 

 expansum et reflexum ; apertura ovata, longit. totius |^ paulo 

 superans. 



Longit. 12| millim., diam. 7 ; apertura 5| longa, 3| lata. 



Hah. On the plains within 50 miles of Mamboia {Last). 



This is a narrower shell than B. usagarica^ differently 

 banded, and has a smaller body-whorl and a larger spire in 

 proportion to the length of the aperture. Only a single speci- 

 men is at hand, and in this, of the three dark zones on the 

 penultimate whoid, the uppermost and lowest are quite close 

 to their respective sutures, and the intervening band falls 

 just above the middle. The three apical whorls are of a rich 

 purple-brown colour, which gradually passes into a paler tint 

 on the succeeding volution. 



Bulimus (^Cerastus) mamhoiensis. (PI. V. fig. 7.) 



Testa elongata, conica, turrita, subpellucida, albo-cornea vel opal- 

 escens, nitida, anguste umbilicata, liris obliquis confertis tenuibus, 



._ J 



