432 MOLLUSCA. 
Inhabits Manila. 
Much like U. Bengalensis and U. foliaceus. In the former, both 
ends of the ventral margin are angular, the posterior side is dilated 
and angular at tip, and the interior is less bright red. The form of 
this is rather elliptical than ovate. U. foliaceus is smaller, thinner, 
compressed, and has a plumbaginous nacre. 
Figures 541, 541 a, 541 4, three views of the shell; 541 c, undulations 
of the beaks. 
Unio raMeEticus (Gould). 
T. parva, tenuis, transversa, oblongo-ovata, convexiuscula, epidermide 
JSusco-castaneo induta; margine dorsah arcuato ; margine ventrah 
rectiusculo ; latere antico angusto ; latere postico oblique rotundato ; 
apicibus haud elevatis ad quadrantem anteriorem sitis ; dente car- 
dina obliquo, compresso, valido ; dente laterali brevi, recto: marga- 
rita subpurpurea. 
Unio famelicus, Goutp; Proceed. Boston Soc. Nat. Hist., iii. 294. 
Nov. 1850. Expedition Shells, 88. 
SHELL quite small, thin, inequilateral, transversely elongated, some- 
what obliquely ovate: dorsal edge ascending, regularly curved, and 
somewhat more so than the ventral margin, which varies from slightly 
convex to slightly concave ; anterior end circularly rounded : posterior 
end somewhat declining, obtusely rounded at tip, which is near the 
ventral margin: beaks at anterior fourth, shghtly elevated, much 
eroded, of a light bronze-green colour; disk convex; umbonal slopes 
full, not angular; epidermis yellowish-green on posterior slope, dusky 
on disk: surface rather smooth, the lines of growth fine and regular : 
some indications of radiating stri# on the disk: nacre pale greenish- 
white: cardinal tooth very oblique, elevated, compressed, triangular, 
striated, double in the right valve: a considerable thin, rounded, 
curved space intervenes before coming to the lateral tooth, which is 
short, straight, double in the left valve: cavity of the beaks small and 
shallow: muscular impressions well marked. 

