128 Bulletin American Museum of Natural History [Vol. LIII 
We have not been able to compare directly South African specimens 
with the Abyssinian, but from the information at hand we fail to see the 
necessity of Bourguignat’s specific separation of the Abyssinian form. 
Other Species of Gyraulus Recorded from the Belgian Congo 
Planorbis (Gyraulus) apertus E. v. Martens 
-Planorbis apertus E. v. Martens, 1897, ‘Deutsch Ost Afr., IV, Beschalte 
Weichth.,’ p. 149, Pl. v1, fig. 17. Gmruatn, 1912, Bull. Mus. Hist. Nat. Paris, p. 80; 
E9O1G, op:..ct.; p. 1938) . 
Lake Edward: near Kirima on the northwestern shore (type locality; Stuhl- 
mann Coll.); near Kasindi (Gromier Coll.). 
It is possible that this species, of which we have seen no specimens, should be 
placed in the subgenus Hippeutis. 
Planorbis (Gyraulus) lamyt Germain 
Planorbis lamyi GerMAIn, 1905, Bull. Mus. Hist. Nat. Paris, p. 256; 1908, 
‘Rés. Scientif. Voy. Afrique Foa,’ p. 688, figs. 4 and 5. 
Lake Tanganyika: at the southern end (type locality; Foa Coll.). 
Subgenus Hiprevtis J. de Charpentier 
Planorbis subgenus Hippeutis ‘‘ Agassiz’’ J. DE CHARPENTIER, 1837, Neue Denk- 
schr. Allg. Schweiz. Ges. Naturw., I, ‘Cat. Moll. Terr. Fluv. Suisse,’ p. 22. Type by 
designation of Clessin (1886): Planorbis complanatus Draparnaud=P. fontanus 
Lightfoot, one of the two species originally included. 
Shell small or of moderate size, lenticular, convex above and narrowly and deeply 
umbilicate below. Spire of very few whorls, the last very broad, deeply embracing 
the foregoing, angular or subcarinate. Aperture lunate or subtriangular. The 
anatomy of the genotype has apparently not been worked out. In appearance Hip- 
peutis is like Segmentina, but it lacks the internal lamelle. 
According to Germain this subgenus is strictly Palearctic, yet the’ 
two following Ethiopian species appear to be true Hzppeutis. 
Planorbis (Hippeutis) benguelensis Dunker=Planorbis benguelensis DUNKER, 
1845, Zeitschr. f. Malakoz., IT, p. 164; 1853, ‘Ind. Mollusc. Guin. Infer.,’ p. 8, Pl. 1, 
figs. 1-4. Planorbis bengalensis SowERBy, 1877, ‘Conchol. Iconica,’ XX, Planorbis, 
Pl. tv, fig. 27. Benguela. 
Planorbis (Hippeutis) junodi (Connolly) = Hippeutis gunodt CONNOLLY, 1922, 
Ann. Mag. Nat. Hist., (9) X, p. 121. Nwambukoto, Rikatla, Portuguese East Africa. 
It is possible that Planorbis apertus E. v. Martens should also be 
referred to this subgenus. 
SEGMENTINA Fleming — 
Segmentina FLEMING, 1817, ‘Edinburgh Encyclopedia, Conchology,’ ed. vu, vol. 
XI. Monotype: Nautilus lacustris (Lightfoot) Montagu=Planorbis nitidus 
O. F. Miiller. 
. 1We have been unable to consult the original account of Segmentina. 
