202 Bulletin American Museum of Natural History (Vol. LIII 
Kobelt (1912, in Martini and Chemnitz, ‘Syst. Conch. Cab., n. F., 
I, Ampullariide,’ Pl. xxviu, figs 15-16) figures under the name “ Lanistes 
congicus’’ a shell from the Crystal Mountains in Gaboon (Lamothe Coll.) 
which certainly belongs to the subgenus Leroya. Whether this really 
belongs to L. stuhlmanni, as has been claimed by C. R. Beettger [1913, 
Ann. Soc. Zool. Malacol. Belgique, XLVII, (1912), p. 105] or to some 
undescribed form could only be established from a study of specimens. 
Other Species of Leroya Recorded from the Belgian Congo 
Lanistes (Leroya) bourguignat: (Grandidier) 
Leroya bourguignati GRANDIDIER, 1887, Bull. Soc. Malacol. France, IV, p. 191. 
BourGuIGNaT, 1888, ‘Iconogr. Malacol. Tanganika,’ Pl. vi, figs. 2-5; 1889, ‘Moll. 
Afrique Equator.,’ p. 180; 1890, Ann. Sc. Nat. Zool., (7) X, p. 79, Pl. v1, figs. 2-5. 
E. A. Smiru, 1904, Proc. Malacol. Soc. London, VI, 2, p. 96. 
Lanistes (Leroya) farlert var. bourguignati Grandidier. E. v. Martens, 1897, 
‘Deutsch Ost Afr., IV, Beschalte Weichth.,’ p. 172; Pl. v1, fig. 34. 
Lanistes (Leroya) bourguignati Grandidier. ANcry, 1907, Bull. Scientif. France 
et Belgique, (5) IX, (1906), p. 250. 
Originally described from East Africa, without more definite locality. Bourguig- 
nat, however, records it from the Vuami River, the Malagarazi River, and the eastern 
shore of Lake Tanganyika. 
Viviparide 
Shell turbinate, smooth, tuberculate or carinate, perforate or with solid axis, 
covered with an olivaceous or dark, often banded, periostracum; aperture shortly 
ovate or rounded, with simple lip. Operculum corneous, concentric throughout or 
with a paucispiral center. 
Tentacles acute, equal in the female, the right one often truncate or recurved in 
the male, where it serves as a penis; eyes on low swellings at the posterior bases of 
tentacles; there are two cervical lobes, of which the right is larger and serves as a 
siphon. The foot is ample, truncate in front, rounded behind. Radula with a wide 
central tooth without basal denticles; lateral teeth rhomboid, marginals narrow; 
cusps of all the teeth are finely denticulate (Viviparinse) or smooth (Lioplacinz). 
Viviparide occur in fresh waters of all the continents except South 
America. .The greatest differentiation of the family is in the Holarctic 
Realm, where they are known to have existed since Mesozoic times. 
In the Ethiopian Region this family comprises the genera Vivi- 
parus and Neothauma. 
Neothauma differs primarily from Viviparus in the shape of the 
outer lip, which is distinctly expanded in the middle and sinuate above, 
near the suture, and below, near the columella In Viviparus, the outer 
margin of the aperture is in a plane and shows no upper and lower sinu- 
osity in the full-grown shell. This is true even in the thick-shelled species, 
such as V. mweruensis, which approach Neothawma somewhat in shape. 
Various anatomical distinctions have also been indicated. 
