1927] Pilsbry-Bequaert, The Aquatic Mollusks of the Belgian Congo I 
foreshortened in the figure. The lateral tooth has four cusps, the second 
largest, as usual; only broken teeth were found. The marginal teeth 
preserved have two forms: a shorter tooth, evidently the outer marginal, 
with tricuspid apex (Fig. 13a, right, lying prone), and a longer, the inner 
marginal, with it bicuspid (Fig. 13a, left, drawn in profile). 
A tricuspid marginal tooth is unusual in this family, where as a 
general rule both marginals are bicuspid; but Pila nevilliana (Annandale 
and Prashad)' has a tricuspid outer marginal, and in Pila maura (Reeve)? 
both marginals have three cusps. 
The only species of this group is Saulea vitrea (Born) = Helix vitrea 
Born, 1780, ‘Test. Mus. Vindobon..,’ p. 383, Pl. xv, figs. 15-16, originally 
described from an unknown locality, but now known to occur in Liberia. 
AFROPOMUS, new genus 
The shell is globose with short conic spire, very solid, imperforate, microscopically, 
densely, spirally lineolate, the lines clearly rippled. The short, concave columella is 
heavily calloused, the callus spreading upward over the parietal wall. The operculum 
is very thin, with no calcareous layer, strongly concave outside; the very large scar 
of attachment to the foot is rippled concentrically. 
Type: Ampullaria balanoidea Goutp (1850, Proc. Boston Soc. Nat. Hist., III, 
p. 196; Moreter, 1851, Journ. de Conchyl., II, p. 267, Pl. vir, fig. 8), from 
Cape Mount, Liberia (Pl. XIV, Figs. 4, 5). : 
This group may resemble the section Limnopomus Dall (1904, Journ. 
of Conchology, XI, pp. 53 and 54) based on a Peruvian species, A. 
columellaris Gould, which we have not seen and which has not been figured. 
Gould’s description appears to indicate a different structure of the 
columella. Dall describes it as having the “‘umbilicus filled with callus.” 
In A. balanoideus there is no umbilicus at any stage of growth, its absence 
being due to closeness of the coil, not to a callous filling. 
The possibility that A. balanoideus is a reversed, that is, secondarily 
dextral, species of Lanistes of the subgenus Leroya is suggested by its 
form, solidity, and sculpture. A definite decision can hardly be made 
until the animal can be fully studied; but such a relationship appears 
highly improbable. 7 
If Saulea and Afropomus turn out to be brevisiphonate forms, they 
will be dissociated from Pomacea and brought near Lamstes. As they 
differ a good deal from one another and cannot be assimilated to any 
other Old World genera, it will probably be best to give both generic 
rank for the present. 
1Annandale and Prashad, 1921, Rec. Indian Mus., XXII, p. 8, fig. 1, B. 
2Annandale and Amin-ud- Din, 1921, Rec. Indian "Mus., Sct, Ds Be fig. 8. 
