1893.] SHELLS FROM BRITISH CENTRAL AFRICA. 639 



23. Melania mweruensis. (Plate LIX. fig. 12.) 



Testa elongata, acvminata, alhida, pnnctis riifis, in seriehus 

 ti'ansversis disposiiis, ornata, epidei'^nide iennissima pallide oli- 

 vacea indtita ; spira elont/ata, aaiminata ; anfractus circiter 10, 

 fere plani,, inferne ad suturam leviter coiistricti vel cancdicidati, 

 plicis obliqins s^dcis sp)iraldnis decussatis instnicti, infra suUtram 

 crasse rnarf/inatl vel halteati. %dtiim(s j)ZtVi5 prope medium 

 obsoletis, inferne transvershn sulcahts ; suhira pariim oblicpia ; 

 apertura acuminato-ovaUs, superne angustata, lonr/it. totius ^ 

 paido superans ; lahnim iemte, superne late et stihprofnnde 

 simiahim ; columella curvata, alba, incrassaia. 

 Lonfi'it. 22 millim., diam. 8; apertura 7 lonr/a, 4^ lata. 

 Hah. Lake M^^■eru (R. Crawshay). 



Tliis species, although spotted like M. tid^ercidata, is sufficiently 

 distinct from that form. The plicre are coarser, the whorls flatter, 

 and the lip more sinuated. The spiral sulci are four in number on 

 the upper whorls and about eight on the body-\vhorl ; they cut 

 through the oblique folds, giving them a more or less nodose 

 appearance. The red dots, A^'hieh are sometimes produced into 

 short transverse lines, fall upon the ridges between the sulci, and 

 never in the grooves themselves. In some specimens the oblique 

 cost^e are almost obsolete, especially upon the last and penultimate 

 whorl. 



24. Melania iMiTATRix. (Plate LIX. fig. 13.) 



Testa elongata, acuminata, epidermide luteo-olivacea amicta, ptmctis 

 rufis p)aucis sparsls picta ; anfractus 8-9, fere planmscidi, 

 costis oblique arcuatis 16-18, quadriscriatim granosis, instnicti, 

 idtimus infra medium transvershn stdcatus ; apertura ovata, 

 sxiperne acuminata, longit. totius ^ adcequans ; labrum supra 

 late sinuatum, antice prominens ; columeUa inferne arcuata, 

 incrassata, alba, rejiexa. 



Longit. 21 millim., diam. 8 ; apertura 7 longa. 



Hub. Lake Mweru (7?. Crnvjshay). 



This species is like 31. tuberculata, but has less coarse whorls, 

 more distinct ribbing and granulation. 



25. Melania crawsttayi. (Plate LIX. fig. 14.) 



Testa angusta, elongata, albida, epidermide pallide olivacea induta ; 

 anfractus 9, infra suturam serie conspicxia, obliqtia, conferta 

 iuberculorum ciacti, infra nodulos constricti, delude conve.vius- 

 cidi, lirisquetrUms, quarum suprema nodosa, spiraliter instructi, 

 ultimus liris circiter 9 ductus; apertura anguste ovata; labrum 

 tenue ; columella arcuata, alba, incrassata. 



Longit. 17 millim., diam. .5| ; apertura 5| longa, 3| lata. 



Uah. Lake Mweru (7^. Crawsliay). 



The row of tubercles bordcnung the suture is prominent and very 

 remarkable. Beneath comes a broad constriction, below which are 

 three transverse ridges, of which the uppermost is ornamented 



