NODULARIA 967 
right valve. Cardinals rather solid, stumpy, that of the right 
valve accompanied in front by a low, lamellar auxiliary tooth. 
Laterals nearly straight, high. Interval short, rather smooth. 
Anterior cicatrices distinct, deep; posterior distinct and very 
faint. Dorsal cicatrices united to a narrow groove situated at 
the inner side of the interval. Beak-cavities rather deep. Na 
cre silvery. 
Length 53, height 26, diam. 18 mm.” (Haas). 
‘Type locality, Hainan. 
Nodularia denserugata Haas, Ann. Mag. Nat. Hist., (8), VI, 
1910, p. 496; Con. Cab., Unio, 1910, pl. vii, figs. 3-4. 
NopuLarRia Brw-& (Kobelt). 
Shell somewhat elongated, solid, subinflated, inequilateral ; 
beaks apparently rather full, their sculpture not observed ; pos- 
terior ridge well marked, subangular, ending in a sharp point 
on the median line; base line nearly straight in front, full be- 
hind the middle ; anterior end rounded, subangular above; out- 
line of dorsal slope evenly curved; surface with faint, uneven, 
growth lines; epidermis brown or blackish, shining; pseudo- 
cardinals subsolid, somewhat split into denticles; laterals 
curved; beak cavities impressed; muscle scars rather deep, 
small; nacre dirty flesh-colored or brownish with a coppery 
or bronzy iridescence. 
Length 45, height 22, diam. 16 mm. 
Lake Biwe, Japan. 
Unio biwe Kosgir, Abh. Senck. Nat. Ges., XI, 1879, p. 425, pl. 
XXUI, figs. 2-4. 
Nodularia biwe Simpson, Syn., 1900, p. 810.—Haas, Con. 
Cab., Unio, 1910, p. 94, pl. 1x, figs. 6-8. 
A small, solid, shining, dark colored species. At the time 
ot writing the Synopsis I had never seen this shell, but have 
since had an opportunity of examining authentic specimens. 
It should be placed in the group of N. dowglasie instead of 
that of N. japanensis. It differs from the latter species in be- 
ing considerably more wedge-shaped when viewed from above, 
and in having different nacre. 
