962 NODULARIA 
Var. sinuolata (von Martens). 
“Shell elongate, swollen posteriorly, with a distinct point and 
with the ventral margin somewhat incurved. Beaks situated 
at 2-7 of the length, moderately eroded, anterior part of the 
dorsal margin only slightly sloping and passing with a broad, 
scarcely noticeable angle into the short and symmetrically 
rounded anterior margin, the posterior part of the dorsal mar- 
gin as far as the end of the lateral teeth is almost horizontal, 
then in a very obtuse angle it slopes and with the much 
stronger ascending basal margin forms a distinct point. Sculp- 
ture only weak remnants of small folds behind the eroded por- 
tion, elsewhere only concentric growth-lines, which towards 
the basal margin become more pronounced. Epidermis shin- 
ing, dark greenish-brown. Nacre silvery white, in many speci- 
mens somewhat ocre-yellowish towards the beaks. Cardinal 
teeth compressed, the two in the right valve about equal and 
parallel, the upper one in the left valve much more prominent 
than the very weak under one; the lower lateral tooth in the 
right valve is wholly or almost wholly wanting. 
a) Length 56, height at beaks 24, at wing 26, diam. 20 mm. 
b) Length 50.5, height at beaks 21, at wing 22, diam. 18 
mm.” (von Martens). 
Type locality, Naemingang River, near Hatanggyoen, Prov- 
ince of Choellado and the mouth of the western tributary of the 
Imjingang. near Ichoen, Province of Kangwoendo, Korea. 
Unie douglasie var. sinuolatus von Martens, Zool. Jahrb. 
Suppl., VII; 190s, p57. 
Nodularia douglasie sinuolatus Haas, Con. Cab., Unio, 1910, 
P1735 pla Vinee. 6: 
“This form by its somewhat expanded basal margin and 
the strong inflation of the posterior third of the shell is very 
remarkable. It is quite possible that this feature is only an 
unusual strong expression of the characteristic female form, 
that in this portion lie the swollen gills, in which the embryos 
live. In the Naemingang another example was found, which 
represents the usual form of dowglasie in Korea, rather com 
pressed and high, with a straight basal margin and without 
