1927] Pilsbry-Bequaert, The Aquatic Mollusks of the Belgian Congo 445 
Lake Tanganyika: Ujiji (type locality; E. C. Hore Coll.); Kombe on the eastern 
shore, and at the southern end of the lake (W. A. Cunnington Coll.) ; Mpala; Onondo 
at the outlet of the Lukuga (Storms Coll.). 
The beaks of the specimen here figured show a few very low, coarse, 
unequal concentric waves upon which there are irregularly placed 
tubercles. The circular glochidial shell is sometimes retained in the adult 
stage. This specimen measures: length, 80.0 mm.; height, 34.0 mm.; 
diameter, 10.5 mm. It is without definite locality. 
A single valve from Tembwe (Hubert Coll.) measures: length, 112 
mm.; height, 47 mm. 
The type of this species measured: length, 90 mm.; height, 43 
mm.; diameter, 15 mm. 
Pseudospatha tanganyicensi3 livingstoniana (Bourguignat) 
Plate XLV, Figure 4 
Spatha tanganyicensis E. A. Smrru, 1880, Proc. Zool. Soc. London, PI. XXXI, 
fig. 8a. 
Burtonia livingstoniana Bourauienat, 1883, ‘Moll. Fluv. Nyanza-Oukéréwé,’ 
HZ: 
Burtonia tanganyicensis var. livingstoniana Bourguignat. E. v. MarreEns, 
1897, ‘Deutsch Ost Afr., IV, Beschalte Weichth.,’ p. 258. 
Pseudospatha livingstonensis Simpson, 1900, Proc. U. S. Nat. Mus., XXII, p. 
578; 1914, ‘Descript. Cat. of Naiades,’ p. 205. 
Pseudospatha livingstont GERMAIN, 1908, ‘Rés. Scientif. Voy. Afrique Foa,’ p. 
687. 
Burtonia bridouxt BouRGUIGNAT, 1886, ‘Nouv. Malacol., I, Un. et Irid. Tan- 
zanika,’ p. 37. GERMAIN, 1908, ‘Rés. Scientif. Voy. Afrique Foa,’ p. 687, figs. 41 
and 42. | 
Burtonia contorta BourcuIGNAT, 1886, ‘Nouv. Malacol., I, Un. et Irid. Tan- 
gaaika,’ p. 39; 1888, ‘Iconogr. Malacol. Tanganika,’ Pl. xxv1, figs. 3-5. 
Burtonia elongata BouRGUIGNAT, 1886, ‘Nouv. Malacol., I, Un. et Irid. Tan- 
ganka,’ p. 34; 1888, ‘Iconogr. Malacol. Tanganika,’ Pl. xxv, fig. 3. 
Lake Tanganyika: originally based upon Smith’s figure 8a, Plate xxx1 of 1880 
(op. Gt.\, which represents a specimen from Ujiji (E. C. Hore Coll.). 
Vhe specimens we identify as this form differ from P. tanganyicensis 
chiefly hy having the posterior end higher, bringing the post-ligamental 
slope nearly in line with the hinge, and increasing the curvature of the 
ventral margin. We have not seen any shells of the size of P. tangany- 
censis having this contour, and none have been figured; and with further 
growth, such a shell as that we figure certainly could not take on the 
contour of P. tanganyicensis. We therefore doubt whether E. A. Smith’s 
figure 32, Pl. xxxiv of 1881 (Proc. Zool.-Soc. London) was rightly in- 
