NODULARIA 975 
truncated; base line nearly straight; outline of dorsal slope 
curved; posterior end somewhat narrowed and almost evenly 
rounded; surface covered with a very thick, dark, rather 
rough epidermis; teeth strong; pseudocardinals two in each 
valve, inclined to be parallel with the large, granular laterals; 
beak cavities moderately impressed; muscle scars roughened; 
nacre brownish and lead-color, slightly thicker in front. 
Length 66, height 36, diam. 22 mm. 
Lake Biwe, Japan. 
Unio reinianus Koneir, Abh. Senck. Nat. Ges., XI, 1879, p. 
424, pl. XXNIM, fig. 1. 
Nodularia reiniana Simpson, Syn., 1900, p. 8t0o.—Haas, Con. 
Cavs, Unio; 2OrO, p..O7, pl. Xx, fig. 1. 
A curious form, but apparently related to U. japanensis. 
Since writing the Synopsis I have seen a specimen, in bad con- 
dition, which is undoubtedly this species. It came from Lake 
Biwe, Japan, and is larger than that measured by Kobelt. 
Its form, being somewhat long ovate, its solidity, the heavy 
teeth, the pseudocardinals running nearly parallel with the 
straight laterals and the brownish and lead-colored, clouded 
nacre are good characters. 
NopuULARIA UNDULATA Haas. 
“Shell rhomboid-elliptical, rather thin and moderately inflat- 
ed, rounded in front and nearly vertically truncated behind. 
Posterior ridge high, distinctly angulated. Basal margin 
straight or slightly curved. Beaks somewhat prominent, situ- 
ated at 23/100 of the total length, their sculpture consists of 
concentrical, undulated ridges, covering about one-half of 
the disk, and running upwards and backwards across the pos- 
terior slope. E;pidermis of a yellowish-green, shining. Hinge 
consisting of two cardinals and two laterals in the left, one 
cardinal and one lateral in the right valve. The cardinals are 
solid, lamellated, that of the right valve accompanied by a 
very low, lamellar auxiliary tooth. “Laterals long, straight. 
Interval short, broad, not distinctly separated from the car- 
dinal teeth. Anterior cicatrices distinct, deep; posterior dis- 
