LOO CHOO MOLLUSKS. 183 



the hinge-margin red except the cartilage-pit and the plate below it. 

 The larger specimen is a very faint buff within the pallial line, with 

 a faint pink tint on the hinge. 

 Luoina interrupta Lam.* Kudaka Is. 

 Lucina punctata Linn.* Yaeyama. 



CHAMID.ZE. 



Chama semipurpurata Lischke (?).* Oshima Is. 

 Chama lazarus Lam.* Kudaka Is. ; Oshima Is. 

 Chama divaricata Rve.* Kudaka Is. ; Oshima Is. 



CYBENID.E. 



Corbicula sp. undet.* Yaeyama. 



Cyrena fissidens n. sp. PI. VIII, figs. 5, 6. 



Shell resembling C. sinuosa as figured by Clessin (Conch. Cab., 

 pi. 45, f. 1), but the posterior lateral tooth and corresponding pit 

 much slender and somewhat longer, the posterior cardinal tooth in 

 right valve split by a sulcus much broader than the space between 

 the posterior and the next adjacent cardinal teeth. Valves orbi- 

 cular, very convex, lightly wrinkle striate, and covered with a black 

 cuticle. Posterior slope depressed, with a radiating wide and shal- 

 low furrow, rendering the margin slightly emarginate. Dorsal, 

 anterior and basal margins well rounded ; posterior margin obliquely 

 subtruncate. Length 86, breadth 77, diam. 49 mm. 



Yaeyama Is., Loo Choo group. A single specimen collected. 



Cyrena luchuana n. sp. PI. IX, figs. 4, 5. 



Shell large, inequilateral, oblong, the anterior end short, broadly 

 rounded, posterior end long, produced, and squarely truncated ; 

 basal margin gently arcuate, dorsal margin narrowly rounded at the 

 beaks, the anterior slope short and nearly straight, posterior slope 

 long, rectilinear. Valves strong, convex, the posterior dorsal area 

 flat or concave, bounded by a blunt angle, another obtuse angle 

 extending from beaks to lower-posterior extremity. Interior white, 

 stained with buff-olive on the hinge. Cardinal teeth bifid ; ante- 

 rior lateral very short and strong; posterior lateral long, remote 

 from cardinals. Cuticle dull brown, with a yellow under color, ir- 

 regularly wrinkle-striate, lamellose behind, and less so over the 

 whole disk. Length 94, breadth 72, diam, 47 mm. 



Yaeyama Is., Loo Choo group (Frederick Stearns). 



