Shells from Lake Tanganyika. 175 
Reymondia tanganyicensis. 
Testa minima, imperforata, ovata, superne acuminata, polita, sordide 
cornea, infra suturam lineis duabus angustis cincta (una nivea, 
altera inferiore sed contigua nigrescente) ; anfr. 5, convexiusculi, 
ultimus magnus; apertura irregulariter ovata, superne leviter 
acuminata, longit. totius + subsequans ; peristoma paulo incrassa- 
tum, margine externo leviter patulo, columellari valde incrassato, 
expanso, superne labro callo tenui juncto. 
Longit. 34, diam. 13 millim. 
This little shell appears to agree with Bourguignat’s genus 
Girandia and is probably closely allied to his G. preclara. 
That genus and Bazzea, also described by Bourguignat, appear 
to be founded upon very trivial characters and not well dis- 
tinguishable from Reymondia. Indeed, I am almost inclined 
to believe that all of these so-called genera could well have 
been dispensed with until more is known about the various 
species which compose them. The well-known genus J//y- 
drolia would, at present at all events, serve well for their 
reception. 
Rissoa (Horea) Ponsonbyt. 
Testa parva, ovata, superne acuminata, imperforata, vix nitens, 
dilute fusco-grisea; anfractus 7, convexiusculi, striis spiralibus 
numerosis, lineisque incrementi obliquis distinctis plus minus 
cancellati, sutura subprofunda sejuncti, ultimus subglobosus ; 
apertura inverse auriformis, longit. totius 4 fere eequans ; labrum 
intus incrassatum, levissime patulum; columella infra medium albo 
callosa, superne callo tenuissimo labro juncta, 
Longit. 63, diam. 3? millim. ; apertura 33 longa, 13 lata. 
The colour and sculpture of this interesting species recalls 
certain forms of Plecotrema, e.g. Pl. concinna, H. and A. Ad., 
P. monilifera, H. Ad., &e. 
I have created a new section of Rissoide for it, as it does 
not conveniently associate itself with any of the known groups, 
and this (Horea) I have named in honour of Mr. E. Coode 
Hore, the discoverer of this and many other new and inter- 
esting Tanganyikan shells. It may thus be characterized :— 
THorea, subgen. nov. 
Shell small, ovate, transversely striated, and cancellated by 
oblique lines of growth. Aperture with a thickened peri- 
stome; columella also thickened. Operculum unknown. 
