MIOCENE MOLLUSCA AND CRUSTACEA. 6D 
stated by Conrad. In the North Carolina specimens this feature is much 
more pronounced. These features and differences are so marked that were 
there more individuals showing constant characters I should be inclined to 
doubt their specific identity. 
The shells belong to the collection of the Academy of Natural Sciences, 
Philadelphia. 
Family CHAMID®. 
Genus CHAMA Linnzus. 
CHAMA CONGREGATA. 
Pl. 1x, figs. 14-18. 
Chama congregata, Conrad; Am. Jour. Sci., vol. 23, first ser., p. 341; Medial Tert. 
Foss., p. 32, Pl. xvui, fig.2; Tuomey and Holmes, Pli. Foss. 8. Car., p. 23, Pl. vir, 
figs. 7-10; Conrad’s List of Miocene Foss. Atlantic Slope, p. 576; Meek, Check 
List, Smith. Inst., p. 8, ete. 
Shell small, dextrally coiled, lower valve deep, subangular along the 
umbonal ridge; upper valve depressed convex, surface of the shell strongly 
lamellose, the lamellae often expanded into moderately wide fringe-like leaves, 
and marked by numerous small radiating plicee, which are most distinct on 
the expanded portions of the lamellae, where they often form subspinose 
processes or small granulose expansions, especially near the spine. The 
radiating plicee, on the upper valve, are generally finer and more crowded 
than on the other valve, and the lamellz more erect and exsert. Muscular 
imprints large and distinct, very slightly elevated above the general surface 
of the interior, and distinctly striated. Margins of the valves finely crenu- 
lated. 
This species does not differ from C. corticosa, Conrad, in any 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 very fair size as compared with those of C. corti- 
COS. 
Localities: At Shiloh, Jericho, and other places in Cumberland County, 
N. J., and in Maryland, Virginia, and the Carolinas abundantly. Collee- 
tions at Rutgers College and the National Museum, at Washington. 
5 
MON XXIV 
