1927] Pilsbry-Bequaert, The Aquatic Mollusks of the Belgian Congo 401 
median series of short, rather coarse folds or low nodules, and an anterior 
series of fine folds radiating and running below toward the median line. 
The very fine growth-lines of the rest of the shell bear minute epidermal 
threads. The interior is very light blue. Pseudocardinals in the right 
valve very much compressed; in the left valve single, or with a second 
low, rudimentary one below the beaks. | 
Length, 52.0 mm.; height, 42.0 mm.; diameter, 22.0 mm. 
persed it Po tae) “ 18.5 
The identification of this species was made possible by Germain’s 
figure. In transferring the species to the genus Unio he changed the 
name on account of the prior Unio elegans of Lea; but if the mussel 
belongs to Cxlatura, as we believe, this change is not necessary since de 
Rochebrune did not originally describe his species in the genus Unio. 
Except in the form of the pseudocardinal teeth C. elegans closely 
resembles Unio gabonensis Kuster. C. putzeysi (Preston) (= U. submigra 
Preston) is a wider shell, with the beaks less anterior. C. elegans appears 
rather closely related to C. equatoria (Morelet), and the scarcely sep- 
arable U. landanensis Schepman, both of these being less elevated 
than our shells. ; 
Celatura equatoria (Morelet) 
Unio xquatorius More et,’ 1885, Journ. de Conchyl., XX XIII, p. 31, Pl. m1, 
fig."9 (type locality:» Mayumba River, district of Cacongo, 3° S., French Congo). 
DAUTZENBERG AND GERMAIN, 1914, Rev. Zool. Afric., IV, 1, p. 68. : 
Nodularia xquitoria Morelet. Stmpson, 1900, Proc. U. 8. Nat. Mus., XXII, 
p. 823. 
Celatura equatoria Morelet. C. R. Barreer, 1913, Ann. Soc. Zool. Malacol. 
Belgique, XLVII, (1912), p. 110. 
Nodularia (Cexlatura) xquatoria Morelet. Simpson, 1914, ‘Descript. Cat. of 
Naiades,’ p. 1032. | 
Unio landanensis ScHEPMAN, 1891, Notes Leyden Mus., XIII, p. Lid, Picwies, 
figs. 3a-b (type locality: Landana, Portuguese Congo). GrErMaIn, 1907, Bull. Mus. 
Hist. Nat. Paris, p. 430, fig. 29. . 
Channel leading from Lake Kabamba to the Lualaba River at Mulongo, between 
Kikondja and Ankoro (J. Bequaert Coll.). P. Hesse bought a valve of this species 
from natives at Banana. Simpson records having seen specimens from Leopoldville 
and different localities in the Congo drainage. 
Leopoldville (J. Bequaert Clon. 
Three specimens from Leopoldville appear referable to this species, 
which is lower and less inflated than C. elegans. The largest measures: 
Length, 40.5 mm.; height, 22.0 mm.; diameter, 15.7 mm. 
Simpson found embryos in the inner gills only. 
