1901.] NATURAL SCIENCES OP PHILADELPHIA. 209 



I have seen a good many specimens, differs constantly in its long 

 form and the different shape of the posterior end. 



Lima Hirasei n. sp. 



Shell inequilateral, thin, white, broadly gaping anteriorly, 

 slightly so posteriorly, compressed, the valves but little convex; 

 beaks a trifle in front of the middle of the short hinge-line. An- 

 terior auricle minute, triangular, acuminate, bent inward; posterior 

 auricle narrow. Cavity of the beaks rather deep. A strong rib 

 runs along the posterior margin slightly within the edge. Surface 

 closely and very finely striate radially, the striation obsolete ante- 

 riorly and on the posterior slope and auricle. 



Length 18, alt. 21, diam. 7.5 mm.; length of hinge-line 

 6.5 mm. 



Hirado, prov. Hizen, Kiusiu, Japan (Mr. Y. Hirase). 



L. orientalis Adams and Keeve, and most of the other small 

 Oriental species, are much more coarsely sculptured than this 

 species. L. Dunkeri E. A. Smith is evenly striated throughout, 

 the stride slightly diverging from a median line, and it is nearly 

 equilateral. In L. Hirasei striation gradually becomes obsolete 

 on the anterior half of the valves, is abruptly discontinued at the 

 posterior slope, and there is no divarication from a median line. 

 The shell is conspicuously inequilateral. 



The species is named for my esteemed Japanese correspondent. 

 L. Dunkeri also occurs at Hirado, Hizen, whence specimens have 

 been received from Mr. Hirase. 



Area (Scapharca) nipponensis n. sp. 



Shell of medium size, thin, inflated, the left Valve decidedly 

 larger, the beaks full, moderately elevated, incurved and 'turned 

 slightly forward, situated at the anterior two-fifths of the hinge- 

 line. Sculpture the same in both valves, consisting of 37 or 38 

 equal radial ribs, which are nearly flat-topped, at least near the 

 periphery, and separated by interspaces narrower than the ribs; 

 the whole marked by slight growth-lines in denuded shells. Cov- 

 ered with a thin chestnut cuticle, which is densely, minutely 

 striate, and bears spaced bristles in the intercostal spaces, on the 

 median and posterior portions of the valves, and on the anterior 

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