Mollusca from South Africa. | 607 
conica, apice antice prominulo, subacuto, sinistraliter inclinante, 
superficie, precipue apud apicem, undique radiatim tenuissime 
striata, intus nitida, cornea, margine lacteo. 
Alt. 3, long. 6, diam. 5 mm. 
Hab. Gordon Falls, Natal. 
This interesting addition to the South-African fauna differs 
from the two Ancyli hitherto described from this region, viz. 
caffer, Krauss, and transvaalensis, Craven, not only in torm, 
but above all in the minute radiating striolations: the apex, 
inclining to the left, is placed well forward, the texture 
thin, and substance horny, pellucid. We have, towards 
the elucidation of this species, studied the elaborate paper of 
Mr. Bryant Walker on the Eastern North-American Ancyli*, 
in which the genus is subdivided into two sections, viz. :— 
(a) Levapex.—Shell usually depressed, apex obtuse or 
subacute, smooth. 
(b) Ferrissia.—Shell usually elevated, apex acute, 
radially striate. 
It is therefore to the second of these subdivisions that this 
species, as also the next, belongs. 
{ 
Ancylus (Ferrissia) stenochorias }, sp. n. 
(PI. XXXL. fig. 1.) 
A. testa anguste oblonga, tenui, olivacea, conica, corneo-hyalina, 
intus omnino pallide cornea, nequaquam pallidi-marginata, apice 
antico prominulo, sinistraliter inclinante, obtuso, superficie radia- 
tim obscure striatula. 
Alt. 3, long. 8, diam. 4°50 mm. (spec. maj.). 
Hab. Ebb en Vioed, Port Elizabeth. 
The extreme narrowness of this little shell, we think, is of 
specific value. The radiating strie are very obscure and only 
discernible with the aid of a lens. We have seen several 
examples, all precisely alike. 
Planorbis leucochilus t, sp.n. (Pl. XXXI. fig. 3.) 
P. testa parva, depressa, cornea, tenui, subhyalina, levigata; an- 
fractibus quatuor, tumidulis, suturis utrinque subimpressis, discis 
ambobus simillimis, paullum rotundatis; apertura depresso-lunata, 
peristomate tenui, albescente. 
Alt. °70, diam. 2°50 mm. 
fab, Killarney Lake, Pietermaritzburg, Natal (Burnup). 
* ‘Nautilus,’ vol. xvii. no. 2, p. 18, and no. 3, pp. 25 sqq. 
T orevoxdpia, narrowness of space, 
£ Aevkds, xeiAos, white-lipped. 
