1927] Pilsbry-Bequaert, The Aquatic Mollusks of the Belgian Congo 23¢ 
Length, 8.8 mm.; diameter above aperture, 2.6 mm.; 11 whorls, the apex lost? 
10 ribs on the penult whorl. 
Length, 8.5 mm.; diameter above aperture, 2.1mm.; 12 whorls, the apex entire; 
10 ribs on the penult where 
Length, 7.3 mm.; diameter above aperture, 2.0 mm.; 10 whorls, the apex lost; 
10 ribs on the penult shel: 
Length, 7.7 mm.; diameter above aperture, 2.4 mm.; diameter including outer 
lip, 2.7 mm.; 844 bene the apex truncate; 10 ribs on phe: penult whorl. 
Anceya admirabilis Bourguignat 
Text Figures 33a, 34b, and 35a-c 
Anceya admirabilis BourcuiGNat, 1889, ‘Moll. Afrique Equator.,’ p. 119, Pl. 
vil, figs. 10-11. E. A. Smrru, 1904, Pree. Malacol. Soc. London, VI, 2, p. 97. Gur- 
MAIN, 1905, Bull. Mus. Hist. Nat. Paris, p. 260. Ancry, 1907, Bull. Scientif. France 
et Belgique, (5) IX, (1906), pp. 255 and 267. 
Lake Tanganyika: between Mpala and Mlilo (type locality); Mpala (Guillemé 
Coll.). 
a b *C 
Fig. 34 : Fig. 35 
Fig. 34. Sections of a, Anceya giraudi pourgenst; b, A. admirabilis Bourguig- 
nat. 
Fig. 35. a-c, Anceya admirablis Bourguignat. T cana ee 
Bourguignat’s type was said to have a single lamella, the columellar, 
and to measure 8 mm. long, 2 mm. wide, of 10-11 whorls. Our spec- 
imens from Tanganyika (L. Stappers Coll.) agree in sculpture with his 
figure which we reproduce in Fig. 33a. 
»< This species is the most slender of the carinate Anceyx now known, 
regularly tapering, the whorls quite convex, each with eight rather sharp, 
curved, noticeably protractive axial ribs, separated by regularly con- 
cave intervals; on the latter part of the last whorl they become obsolete. 
The base is bounded by a narrow, strongly expressed carina, and below 
that is flat and finely striate radially. The color is ecru-olive or some- 
