972 NODULARIA 
that of the left valve lies under the beak and is stumpy, trian- 
gular and smooth. Laterals short, thick, a little curved, 1-2 in 
each valve. In the four specimens before me they are as 
follows: 
RIGHT LEFT 
a) 
b) 2 2 
@) I 2 
d) 2 2 
The angle of the cardinal teeth is 30°; of the laterals 0°. 
Both the anterior and posterior muscular impressions are 
merged; those of the posterior retractors, however, show a 
tendency to be differentiated ; dorsal scars united in a deep pit 
under the interval. Nacre reddish in the beak cavities, bluish 
towards the margin. 
Length 50, greatest height 36, at beaks 30, diam. 22 mm.” 
(Haas). 
Type locality, Japan. 
Nodularia parcedentata Haas, Con. Cab., Unio, 1910, p. 104, 
pl. xia, figs. 3-4; Nachr. Deutsch. Mal. Ges., 1911, p. 43. 
NODULARIA CONTINENTALIS Haas. 
“Shell elongate-elliptical, solid, inflated, somewhat truncated 
in front and slightly arcuate behind. Posterior ridge moder- 
ately rounded. Basal margin slightly sinuate at its posterior 
part. Beaks not prominent, eroded, situated at 21-100 of the 
total length; their sculpture is not to be seen when adult, in 
young sheils it consists of few concentrical, slightly looped 
ridges, the posterior loops running upwards across the pos- 
terior slope. Epidermis of a rather dull black. Hinge con- 
sisting of two cardinals and two laterals in the left, one car- 
dinal and one lateral in the right valve. Cardinals solid, 
stumpy, jagged on the surface, a narrow lamellar auxiliary 
tooth standing in front of the one of the right valve. Laterals 
long, high and curved. Interval short, broad, covered with 
small. denticular structures. Anterior cicatrices united to a 
