260 Bulletin American Museum of Natural History [Vol. LIII 
three whorls have the spiral below the suture prominent, beaded, forming a narrow, 
horizontal ledge; it is separated from the following spiral by a space slightly wider 
than those separating subsequent spirals. On the penultimate whorl there are three 
tubercular spirals below the prominent sutural one (and sometimes a fourth spiral 
is visible Just above the suture). The last whorl has about 7 spirals, of which three or 
four are tuberculate except in the largest shells, in which only the upper one remains 
so sculptured, the others becoming nearly smooth. Axial sculpture consists of fine 
strie of growth, and sometimes weak ribs on the penultimate whorl. The aperture is 
ovate, biangular posteriorly. ) 
Length, 13.5 mm.; diameter, 5.0 mm.; aperture, 5.0 mm.; about 5 whorls 
remaining. Type. 
Length, 14.5 mm.; diameter, 6.0 mm.; aperture 5.0 mm.; about 3 whorls 
remaining. ) 
A species of the group of M. mweruensis, resembling M. crawshayi 
(Smith) by the prominence of the subsutural cingulum, but distinguished 
by its small size, more slender shape, and more delicate sculpture. 
A single specimen from Yakasa (J. Bequaert Coll.) appears to come. 
near langz; but it is more slender, with no beaded spirals and weak sub- 
sutural cords. 
Melanoides langi zambiensis, new subspecies 
Plate XXII, Figure 3 
Mud-banks of the Congo River about midway between Malela and 
Zambi, numerous specimens (H. Lang and J. Bequaert Coll.). 
The shell differs from M. langi chiefly by its larger size and the numerous spiral 
threads of the base. : 
Length, 20.0 mm.; diameter, 7.0 mm.; length of aperture, 7.0 mm.; 544 whorls 
remaining. Type. | 
‘Length, 19.5 mm.; diameter, 7.0 mm. 
a 19.0 ee 6,2 
Melanoides nsendweensis (Dupuis and Putzeys) 
Plate XXII, Figures 7 and 8 
Melania nsendweensis Dupuis anp Purzenys, 1900, Ann. Soc. Malacol. Belgique, 
XXXV, Bull. Séances, p. xvii, figs. 28 and 29. DautzENBERG AND GERMAIN, 1914, 
Rev. Zool. Airies, TV, 1; p. 64 
In the Lualaba River at Nsendwe (type locality), Nyangwe, and Lokandu 
(Dupuis Coll.). In the same river at Kibombo and Nyangwe (J. Bequaert Coll.). 
The species is strongly ribbed, the ribs prominent or sometimes 
tuberculiferous at the sutural or peripheral ends, the base having about 
four spiral cords, of which the second from below is often largest. The 
outer lip is markedly sinuous, advancing in the lower part. The length 
is given by Dupuis as 14 to 20 mm. Those before us from Nsendwe are 
12.5 to 14.0 mm. long. 
