932 QUADRUL,A 
hinder end an obtuse, subdeflexed, truncated rostrum ; ventral 
margin in the young decidedly curved, in the adults scarcely at 
all. Beaks somewhat swollen, eroded. Nacre white, reddish- 
yellow in the centre. Cardinal teeth almost horizontal, sub- 
parallel, two in the left valve; the anterior delicate, smooth, 
the posterior heavier, subtrigonal, longitudinally sulcate; one . 
in the right valve stout, rugose; lateral teeth slightly curved, 
rather smooth, elongate, two in the left valve, the lower sub- 
duplicated posteriorly : one in the right valve. Anterior mus- 
cular impressions longitudinally oblong, rugose; pallial line 
often transversely striate. 
Specimen maximum, long. 120, alt. ad vertices 45, posterior 
65, diam. 36 mm. 
Specimen medium, long. 82, alt. ad vertices 35, posterior 46, 
diam, 25 mm. 
Beaks situated at one-fifth of the length; ligament extended 
to three-fifths of the length.” (von Martens). 
Type localitv, Soeul, Amnokgang near Wiwon and Puk- 
chang, Korea. 
Unio gottschei von Martens, S. B. Nat. Fr., 1894, p. 215.— 
SIMPSON, Syn., 1900, p. 862. 
Unio (Ouadrula) gottschei von Martens, Zool. Jahrb. Suppl., 
WL O05) P45, ple oe 
“Groups with the Chinese U. leai Gray and, young, scarcely 
distinguishable, but the anterior end of our species is not so 
broadly rounded as in U/. leai, the length of the shell in pro- 
portion to its height is greater, the sculpture is weaker and is 
more closely drawn together in tuberculous ridges, there 
being few isolated warts. I know of no similar species from 
Japan-” 
QuapruLtA MANsuyI Dautzenberg and H. Fischer. 
“Shell very thick and heavy, elongate trapezoidal, rounded 
in front, angulated behind, surface with irregular lines of 
growth and in the centre of the disk some radiating, subverti- 
cal, more or less confluent, folds, which on the posterior slope 
become much stronger, slightly nodulous and divergent; an- 
