1927] Pilsbry-Bequaert, The Aquatic Mollusks of the Belgian Congo 181 
fading toward the outer edge. Scar much less than half the total width, 
with a large smooth area; between that and the columellar side irregu- 
larly rugose concentrically. Length, 55.0 mm.; width, 31.0 mm. 
In P. ovata the operculum is relatively wider, with a larger scar. P. 
congoensis amplior has a much wider. operculum, its columellar margin 
less sigmoid. 
“According to Dr. J. Rodhain, common in the papyrus and other 
swamps of this region.” (H. L.) 
Other Species of Pzla Recorded from the Belgian Congo 
Pila ovata (Olivier) 
Ampullaria ovata OLIVIER, 1804, ‘Voyage dans l’Empire Othoman,’ II, p. 39, 
footnote; (an x11), Atlas, Pl. xxx1, fig. 1 (type locality: Alexandria, Egypt). E. A 
Smrru, 1880, Proc. Zodl. Soc. London, p. 348. Cross, 1881, Journ. de Conchyl., 
XXIX, p. 110. PELsENEER, 1886, Bull. Mus Hist. Nat. Belgique, IV, p. 104. 
BourguienatT, 1888, ‘Iconogr. Malacol. Tanganika,’ Pl. v1, fig. 1; 1890, Ann. Sc. 
Nat. Zool., (7) X, p. 74, Pl. vi, fig. 1. R.Srurany 1894, in O. Baumann, ‘Durch 
Massailand zur Nilquelle,’ p. 299. E. v. Marrens, 1897, ‘Deutsch Ost Afr., IV, 
Beschalte Weichth.,’ p. 158. E. A. Smrru, 1904, Proc. Malacol. Soc. London, VI, 2 
p. 100. Germain, 1905, Bull. Mus. Hist. Nat. Paris, p. 256 (var. major); 1913, op. 
cit., p. 356; 1908, ‘Rés. Scientif. Voy. Afrique Foa,’ p. 668, fig. 23 (on p. 669) (var. 
major). HE. A. Smiru, 1906, Proc. Zo6l. Soc. London, I, p. 184. Ancry, 1907, Bull. 
Scientif. France et Belgique, (5) IX, (1906), pp. 250 and 262. G. B. Sowrrsy, 1910, 
Proc. Malacol. Soc. London, IX, 1, p. 60. C. R. Ba@rremr, 1918, Ann. Soc. Zool. 
Malacol. Belgique, XLVII, (1912), p.101. DautTzENBERG anD GERMAIN, 1914, Rev. 
Zool. Afric., IV, 1, p. 48. 
Pachilates ovata Olivier. KoseEut, 1912, in Martini and Chemnitz, ‘yt. Conch. 
Cab., n. F., I, Ampullariidg,’ p. 46, Pl. xxx1, fig. 3. (Puippi, 1851, op. cit., Pl. 
XIV, fig. 5). 
Lake Tanganyika: near Ujiji (J. C. Hore Coll.); at the southern end (W. A. 
Cunnington Coll.); at the northern end (O. Baumann Coll.); near the outlet of the 
Lukuga River; Kibanga; Karema, Ufipa; Mbwe. The var. major was described by 
Germain from the southern end of Tanganyika (Foa Coll.). 
The occurrence of typical P. ovata in Lake Tanganika seems beyond doubt. C. 
R. Boettger has also recorded this species from the “Upper Congo” (O. Baumann 
Coll.); and Dautzenberg and Germain list it from Lake Kisale at Kikondja; the 
Congo at Ukaturaka; and the Lualaba at Nyangwe (all J. Bequaert Coll.). These 
identifications appear to us dubious since we have been unable to recognize ovata 
among the many specimens brought back by the Congo Expedition. 
Pila ovata var. bridouxt (Bourguignat) 
Ampullaria bridouzi Boureuienat, 1888, ‘Iconogr. Malacol. Tanganika,’ PI. 
v, fig. 22; 1890, Ann. Sc. Nat. Zool., (7) X, p. 72, Pl. v, fig. 22. E. v. Marrens, 
1897, ‘Dekech Ost Afr., IV, Baechals Weickih.. p. 156. E. A. Smrru, 1904, Proce. 
Malacol. Soc. London, VI, 2,p.100. Ancry, 1907, Bull. Scientif. France et Belgique, 
(5) IX, (1906), pp. 250 and 262. : 
