358 Bulletin American Museum of Natural History [Vol. LIIT 
This form appears to be constantly smaller than H. medizafricana 
with the epidermal laminze more crowded. 
As in mediafricana, there seems to be a wider (typical) and a 
narrower form. The latter (Fig. 800) is like etheriarwm in color, sculpture 
and general form, but is not so high, the height being about 70 per cent 
of the length. One opened has in the right valve a very small, tubercular 
cardinal tooth, a strong, short anterior lateral and a long, slender pos- 
terior lateral. The left valve has a much stronger, elongate cardinal 
tooth, forming a prominence over the beak cavity, and well developed 
anterior and posterior lateral teeth. 
Length, 3.7 mm.; height, 2.6 mm.; diameter, 2.0 mm. 
Other Species of Hupera Recorded from the Belgian Congo 
Hupera bequaertt Dautzenberg and Germain 
Eupera bequaerti DAUTZENBERG AND GERMAIN, 1914, Rev. Zool. Afric., IV, 1, 
p. 72, Pl. u, figs. 7 and 8. 
Luapula River at Kasenga, living in the texture of the shell of Etheria elliptica 
(type locality; J. Bequaert Coll.). 
This species, though known by the type specimen only, appears quite distinct 
from others by its broad, less inequilateral shape, more like that of some Spheria, 
and by the less projecting beaks. It measures: length, 7.5 mm.; height, 6 mm.; 
diameter, 3 mm. 
HKupera sturanyt (L. Waagen) 
Spherium (Clessinella) sturanys L. WaacEen, 1905, Sitz. Ber. Ak. Wiss. Wien 
Math. Naturw. K1., CXIV, Abt. 1, p. 171, fig. 1 (on p. 167). 
Rapids of the Congo River in the District of the Cataracts (Lower Congo), in 
valves of Htheria (type locality; O. Baumann Coll.). 
This species has not been figured. It is said to measure: length, 5 
mm.; height, 4 mm.; diameter, 1.5 mm. The height is therefore 80 
per cent, the diameter 30 per cent of the length; it is thus higher and 
much more compressed than EH. ferruginea. While the ratio of height to 
length is about the same as in H. mediafricana eth<riarum, the relative 
diameter is only about half as much if the dimensions given are correct. 
PSEUDOCORBICULA Dautzenberg 
Pseudocorbicula DAUTZENBERG, 1908, Journ. de Conchyl., LVI, p. 32. Mono- 
type: Pseudocorbicula alluaudt Dautzenberg. 
Shell rather solid, with the general form and sculpture of Corbicula; rayed. 
Ligament short, external. Right valve having one very weak cardinal and two strong, 
lamellar laterals, projecting at the distal ends; left valve with two very feeble car- 
dinals and a lamellar lateral on each side. The lateral teeth have no trace of verti- 
cal striation or crenulation. The pallial line is entire. 
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