Freshwater- Shells fi'om Central Africa. 163 



Ennea curvilamella. (PI. VI. fig. 8.) 



Testa tenuis, subpellucida, pupiformis, superne conoidea, haud ri- 

 mata, albida ; anfractus 8, convexiusculi, costulis tenuibus 

 obliquis instruct!, in interstitiis mieroscopice spiraliter interrupte 

 striati ; apex obtuse conoidalis, laevis ; anfr. ultimus antice leviter 

 ascendeiis, pone labium profunde efFossus ; apertura parva, longit. 

 totius ^ adgequans, dentibus duobus munita ; perist. album, 

 paulo dilatatum et reflexum ; c(J.umella intus lata, 



Longit. 8i millim., diam. 4 ; apertura 2| longa, 2 lata. 



«3 Q3 oi o 



Hah. Mamboia, at an altitude of 4000 to 5000 feet {Last). 



Of the two teeth in the mouth of this species one corresponds 

 to the indentation behind the outer lip, the other, which is 

 lamelliform, prominent, and curved, is on the body-wall and 

 almost joined to the extremity of the labrura. The ends of 

 the fine riblets give a pretty denticulate appearance to the 

 suture. The microscopic stride do not extend from riblet to 

 riblet, but appear to be only on the left side of the riblets 

 when the shell is examined with the spire upwards. 



Ennea consociata. (Ph VI. fig. 9.) 



Testa pupiformis, superne obtuse conoidea, albida, parum nitida ; 

 anfract. 8, convexiusculi, sutura profunda sejuncti, oblique for- 

 titer striati, ultimus antice paulo ascendens, pone et infra aper- 

 turam scrobiculatus ; apertura subquadrata, ringens, dentibus 4 -5 

 albis, inaequalibiis, instructa, longit. totius i paulo superans; 

 perist. album, sublate dilatatum et reflexum. 



Longit. 7 millim., diam. ^\ ; apertura 2^ longa, 2i lata. 



Hah. Kidete [Emin). 



TJiis is a more slender shell than E. consanguinea^ diffe- 

 rently striated, and it has different teeth in the aperture. Of 

 these one on the outer lip is almost double, a second strong 

 tooth is situated on the columella, a third smaller one within 

 the lower margin, a fourth much curved, hollowed out, lamel- 

 lar one adjoining the outer lip above, and, finally, a sixth 

 minute denticle occurs above the large central tooth on the 

 labrura. 



Ennea ceqiddentata. (PI. VI. fig. 10.) 



Testa parva, cylindracea, superne paulo latior, ad apicem obtusa, 

 albo-pellucida, nitida ; anfract. 6, convexiusculi, laevigati, superne 

 ad suturam subprofundam minute denticulati, ultimus penultimo 

 angustior, prope aperturam longitudinaliter striatus, utrinque et 

 infra scrobiculatus ; apertura subquadrata, quadridentata, alba, 



