NODULARIA 1013 
Unio mequalis ROCHEBRUNE, Bull. Soc. Phila., 1882, p. 44.— 
Simpson, Syn., 1900, p. 862. 
Oxynaia inequalis Haas, Con. Cab., Unio, 1910, pl. xtra, fig. 
Re; pla XV; fie. 7. 
Unio semidecoratus Moret, J!. de Conch., XXXVII, 1880, 
p. 192, pl. virt. fig. 4. 
Nodularia semidecorata SIMPSON, Syn., 1900, p. 810. 
The figure of this species given by Morlet is rather inferior. 
The umbonal region seems to be decidedly sculptured; the 
beaks are higher, and the shell is thinner than is the case with 
N. fischeriana. 
NopULARIA RUSTICA (J,ea). 
Shell subsolid, irregularly ovate, inflated, inequilateral ; 
beaks very full and high, their sculpture coarse, zigzag corru- 
gations, which extend out on to the disk and gradually change 
to subnodulous sulcations; lunule well marked; anterior end 
narrow ; base line almost evenly curved, but slightly produced 
behind the middle; hinge line with the compressed teeth 
curved; posterior ridge angled above; narrowly rounded be- 
low and ending in a blunt point near the median line; epider- 
mis dirty yellowish-green, darker behind; beak cavities rather 
deep; muscle scars impressed ; nacre whitish or bluish-white. 
Length 50, height 36, diam. 25 mm. 
Siam ; Cambodia. 
Umio rusticus Lea, Pr. Ac. N. Sci. Phila:, VIII, 1856, p. 93; 
Ohana tee pb pl xxv, ews: Jl Ac. »N. Sci. Phila., 
III, 1858, p. 204, pl. xxv, fig. 7—Morexer, Ser. Conch., IV, 
T9755p: 353, pl: Xv, fig: 7. 
Margaron (Unio) rusticus Lea, Syn., 1870, p. 31. 
Nodularia rustica Stwpson, Syn., 1900, p. 819. 
Contradens rusticus Haas, Conch. Cab., Unio, 1912, pl. 21, 
figs. 2-4. 
Unio paivanus Morier, Jl. de Conch., XIII, 1865, p. 227. 
Unio cambojensis SowrRny, Conch. Icon., XVI, 1866, pl. xLu, 
fig. 231. 
