UNIO 719 
Unio sriarti Dautzenberg. 
“Shell solid, transversely oval, narrowed in front, expanded 
posteriorly. Beaks at the anterior third of the length. Ante- 
rior extremity short, rounded and compressed; posterior end 
expanded, inflated and very obliquely truncate. Surface with 
irregular striz and lines of growth. An obtuse ridge ex- 
tends from the beaks to the base of the posterior truncation, 
and the posterior slope is ornamented with numerous, oblique 
folds, curved and more or less chevroned near the margin. 
Some similar, but less pronounced, folds appear on the an- 
terior region, near the beaks. Interior of the valves 
nacreous, very finely shagreened. Cicatrices of the anterior 
muscles round, deep and with a small scar at the base of and 
behind the principal one. Cicatrices of the posterior adductors 
subtrigonal. superficial. Hinge not very thick, with two, short 
cardinals in the right valve, slightly roughened, separated by 
a narrow groove, and a long, curved, lamellar lateral; two 
cardinals in the left valve, the anterior short, compressed, 
roughened and erect, the posterior obsolete, and two lamellar 
laterals, curved and quite close together, the upper more prom- 
inent. Color uniform olive-yellow, more or less tinged with 
black; nacre bluish-white. Ligament deep yellowish-brown, 
quite prominent. 
Length 54, height 74, diam. 32 mm.” (Dautzenberg) 
Type locality, La Lufoi, Congo Free State. 
Unio briarti DAUTZENBERG, Ann. Soc. Mal. Belgique, XXXVI, 
T90T, p- 6, pl. 1, fies. 3, °4. 
UNIO MALGACHENSIS Germain. 
“General form of the shell an elongate-siliquiform; valves 
strongly twisted in the infero-posterior region; anterior end 
very short, obliquely rounded at the base; posterior portion 
a little more than three times as long as the anterior, sub- 
rectilinear-elongate, rounded at the end; beaks very large, very 
prominent, incurved anteriorly ; ligament not large, but slightly 
projecting; dorsal margin nearly straight; basal margin 
straight, slightly sinuous in the middle curving upwards 
towards the posterior end; dorsal and basal margins practically 
