NODULARIA 973 
narrow, short groove situated at the inner side of the interval. 
Beak-cavities deep. Nacre silvery, brilliant. 
Length 62, height 36, diam. 25 mm.” (Haas). 
Type locality, Hunan, Middle China.. 
Nodularia continentalis Haas, Ann. Mag. Nat. Hist., (8), VI, 
IQIO, p. 497; Con. Cab., Unio, 1910, p. 92, pl. rx, figs. 4-5. 
“Very near to Nod. japanensis Lea of Japan, the first form 
of this group recorded from the continent.” 
NoODULARIA OMIENSIS (von Heimburg). 
Shell obovate or subrhomboid, narrow in front, rather thin, 
convex, inequilateral; beaks apparently not very full; anterior 
end rounded; base line curved, full behind the middle; poste- 
rior end obliquely subtruncate above, somewhat biangulate 
below ; surface with rather fine, concentric ridges, and more or 
less corrugated subnodulous sculpture; epidermis brownish 
or blackish; pseudocardinals subsolid; laterals curved; beak 
cavities moderate; muscle scars not deep; nacre bluish-white, 
richly iridescent. 
Length 51, height 28, diam. 15 mm. 
Province of Omi, Japan. 
Jnio omiensis VON Heimburc, Nach. Deuts. Mal. Ges., XVI, 
1884, p. 93; Jahrbuch Mal. Ges., XIV, 1887, p. 2, pl. 1, figs. 
B52: 
Nodularia onuensis SIMPSON, Syn., 1900, p. 810.—HAas, Con. 
Cab., Unio, 190, p. 95, pl. 1x, fig. I1. 
Thinner, more obovate and with a richer colored nacre than 
N japanensis. I have seen a single valve of what may be this 
species, which is much more strongly corrugately sculptured 
than the figure given by von Heimburg. It does not differ any 
more in this respect than specimens of N. japanensis do. 
NoODULARIA HIRASEI Haas. 
‘Shell wedge-shaped, thick, heavy, moderately inflated. An- 
terior margin short, regularly rounded; ventral margin quite 
convex; posterior point blunt; posterior margin oblique; dor- 
sal margin slightly curved. Beaks well in front at one-fifth 
of the total length, not very prominent, eroded, rather inflated ; 
