MIOCENE MOLLUSOA AND CRUSTACEA. B5 



Stated by Conrad. In the North Can^lina specimens this feature is inudi 

 more pronounced. Tliese features and differeni-es are so mai-ked that were 

 there more indi^-iduals showino- constant cliaracters I should be incHned to 

 doubt their specitic identity. 



The shells belong- to the collection of the Academy of Natural Sciences, 

 Philadelphia. 



Family CHAMID^E. 



Genus CHAMA Linnaeus. 



Chama congregata. 



PI. IX, figs. 14-18. 



Chama congref/ata, Conrad; Am. Jour. Sci., vol. 2.'3, first ser., p. 341; Medial Tert. 

 Foss., p. 32, PI. XVII, tig. 2; Tiiomey and Holmes, Pli. Foss. S. Car., p. 23, Pf. vii, 

 figs. 7-10; Conrad's List of Miocene Foss. Atlantic Slope, p. 576; Meek, Check 

 List, Smitb. Inst., p. 8, etc. 



Shell small, dextrally coiled, lower valve deep, subang-ular alono- tlie 

 umljonal ridye; upper valve depressed convex, surface of the shell stronglv 

 lamellose, the lamelhe often expanded into moderatelv wide fringe-like leaves, 

 ;nid marked by numerous small radiating plies, which are most distinct on 

 the expanded portions of the hunellos, where they often form subspinose 

 processes or small granulose expansions, especially near the spine. The 

 radiating plicse, on the upper valve, are generally finer and more crowded 

 than on the other valve, and the lamella? more erect and exsert. Muscular 

 imprints large and distinct, very slightly elevated above the general surface 

 of the interiiir, and distinctly striated. Margins of the valves finely crenu- 

 lated. 



This species does not differ from C. eorticosa, Conrad, in anv essential 

 feature, other than in being coiled in the opposite direction. Where they are 

 found associated this one is usually somewhat smaller, but many of the New 

 Jersey specimens attain a Aery fair size as compared with those of C. eorti- 

 cosa. 



Localities. ■ At Shiloh, .Jericho, and other places in (Cumberland Countv, 

 N. J., and in Maryland, Virginia, and the Carolinas abundantly. Collec- 

 tions at Rutgers College and the National Museum, at Wa.shington. 

 MON XXIV ."> 



