PLEIOCENE FOSSILS. 25 



JANIRA. — Schumacher. 



The genus Janira was instituted by Schumacher in 1817, to receive such forms of the 

 genus Pecten as have the lower valve, compared with the upper, larger and more convex, 

 the upper valve flat or concave, and both equilateral. The other characters are the same as 

 those of the genus Pecten. Janira seems to connect Pecten with Spondylus. 



JANIEA HEMICYCLICA. 



Plate VIE., Figs. 1, 2, 3, i. 



Pecten liemicyclicus, Ram. 



J. testa sub-semicirculari, depressa, concentrice striata, inmquivalvi, cequilaterali ; valva 

 infer iore convexa ; costis marginem versus sulcatis ; valva superior e depressa, costis con- 

 vexis, sub-inaiqualibus, 



Description. Shell somewhat semi-circular, depressed, striated concentrically and closely ; 

 inequivalve, equilateral, lower valve convex, ribs, towards the pallial margin, turned up and 

 sulcate ; upper valve depressed, or flat, concave towards the pallial margin, ribs convex ; 

 buccal ears depressed, lower one with a stout ridge. 



This fine fossil has its living representative in Janira (Pecten) jACOBiEA, which it greatly 

 resembles, and from which it is distinguished by its less convex lower valve, and by the 

 absence of the radiating and numerous impressed lines of the ribs. 



Plate VIIL, Fig. 1. Ujyper valve, natural size. 



" 2. Lower valve. 



" 3. Side view of fossil. 



" 4. Outline of the ribs. 



Locality. Grove, Cooper River. 



7 



Museum, College of Charleston, S. C. 



