382 Mr. E. A . Smith or> the Shelf-Fauna of 



II. N^eio Species discovered In/ Rev. E. Ci/ril Gordon. 



Ampullaria nyanzce. 



Testa maxima, globosa, late iimbilicata, solida, ponderosa, epider- 

 mide olivaceo-fusca induta ; anfractus (!, pvimi tres erosi, sequen- 

 tes convexi, mcromeiiti lineis obliquis mediocriter fortibus striisque 

 spiralibns minutis confertissimis sculpti, iiltimus infra peri- 

 ostracum zonis numerosis angustis obsciiris pictus; apertura inverse 

 auritormis, liiteo-albida, zonis spiralibus purpureo-fuscis, praecipiie 

 ad marginem conspicuis, obscure picta, longit. totius |- subaequans ; 

 peristoma baud iucrassatum, iutus plus minus flavescens, pur- 

 pureo-fusco maculatum, margine columellari oblique, mediocriter 

 reflexo, superne flavo. infra purpureo-fusco tincto. 



Alt. 115 millim., diam, maj. loS, min. 85; apertura 80 louga, 

 52 lata. 



Hah. A creek, commonly called Jordan's Nullah, at the 

 south end of the lake. 



This species is the largest recorded from any part of Africa. 

 Ampullaria charmesiana, Billotte *, is nearly as large, and 

 occurs in the Nile above Gondokoro ; that species, however, 

 is longitudinally costulate, lias a narrower aperture, and the 

 peristome is strongly thickened within and tinted with orange. 

 On the contrary, A. nyanzce has a thin peristome without any 

 thickening within, and is cor.spicuously blotched with purple- 

 brown by the terminations of the spiral zones. The surface 

 of this species is very minutely spirally striated, a feature 

 also occurring in A . speciosa, another large form from eastern 

 Africa. That species, like A. charmesiana^ has an orange 

 lip witli an internal thickening. It has a more depressed 

 spire and the whorls are more or less imj)ressed or channelled 

 above at the suture. 



Reeves's figure of A, erythrostoma (Conch. Icon. pi. xiii. 

 fig. 59), if the three apical whorls be concealed, gives a fair 

 idea of the proportions of the present species. 



Ampullaria Gordoni. 



Testa globosa, anguste perforata, zonis numerosis angustis saturate 

 fuscis epidermide olivacea subobscuratis cincta ; anfractus 5, 

 celeriter crescentes, mediocriter convexi, sutura lineari flava 

 sejuucti, plus minus minute et spiraliter striati, ultimus magnus, 

 incrementi lineis obliquis sculptus ; apertura magna, longit. totius 

 ■i fere sequans, intus purpurea zonis extcrnis indistincte notata ; 



* Bull. Soc. Mai. France, 1885, vol. ii. p. 106. 



