1927] | Pilsbry-Bequaert, The Aquatic Mollusks of the Belgian Congo 417 
Aspatharia sinuata (E. v. Martens) 
Plate XXXV, Figures 1-4; Plate XXXVI, Figures 1-3a 
Spatha sinuata I. v. Martens, 1883, Sitz. Ber. Ges. Naturf. Fr. Berlin, p. 73; 
1885, ‘Conchol. Mitth.,’ I, 5-6, p. 190, Pl. xxx1v, figs.5 and 6. Bourcurenart, 1889, 
‘Moll. Afrique Equator.,’ p. 196. Smmpson, 1900, Proc. U.S. Nat. Mus., XXII, p. 899; 
1914, ‘Descript. Cat. of Naiades,’ p. 1333. 
Mutela lukuluensis Preston, 19138, Rev. Zool. Afric., III, 1, p. 61, Pl. v1, fig. 4. 
Mutela mathilde Preston, 1913, Rev. Zool. Afric., III, 1, p. 61, Pl. v1, fig. 7 
(type locality: Shiré River). 
In the Lubi and Lubilash Rivers, Goines 5° and 6° S. uieidan Coll.; type 
locality not more definitely mentioned). Confluence of Lukulu and Luapula on 
(type locality of M. lukuluensis Preston). | 
Aba, abundant in the Aba River; Faradje; Medje (Lang and 
Chapin Coll.).. Avakubi, in the Aruwimi-Ituri River (J. Bequaert 
Coll.). 
Mr. Lang notes that this mussel i is frequently used as food by the 
natives in the region of Aba. 
An Aspatharia very abundant at Aba and Faradje agrees best with 
the account of A. sinuata (v. Martens), though some examples appear 
close to A. stuhlmanni (v. Martens) of the Upper Ituri River, therefore 
not far from our localities. The figure of A. stuhlmanni could pass for 
some of our specimens, but, according to the description, the beaks are 
somewhat less anterior and the ligament is relatively longer. 
Our shells are dingy blackish brown or blackish olive. When washed 
with oxalic acid to remove the iron stain, they vary from olive-brown to 
isabella color and more rarely honey yellow, in either case becoming 
bright or dark green toward the beaks, blackish or olive-brown poste- 
riorly. The middle or the anterior half shows more or less of the 
minute sculpture of rays composed of fine, looped, concentric costule, 
as seen in A. protchet and many other species. The contour is somewhat 
variable; in some specimens the dorsal and basal margins are nearly 
parallel, but more frequently the shell becomes higher posteriorly. 
These variations, as well as the variation in diameter, are shown 1 in the 
figures. 
The loneals of the hinge-plate, from beaks to sinulus, is 43 to 44 
per cent of the total length. The anterior and visceral muscle impres- 
sions are rather deep. The internal color in Faradje shells is pale blue or 
rarely pale pink with olive to dull green stains. In those from Aba the 
pinkish tint is more frequent. There is not much iridescence. In a 
few individuals there is a distinct though low and blunt tooth under a Ane 
beak of the left valve. 
