48 PALEONTOLOGY OF NEW JERSEY. 
Genus BARBATIA Gray. 
BARBATIA MARYLANDICA. 
Plate vu, figs. 2-4. 
Byssoarca Marylandica Conrad: Miocene Foss., p. 54, Pl. Xx1Xx, fig. 1. 
Barbatia Marylandica Conrad: Proc. Acad. Nat. Sci., Phil., 1862, p. 580; Meek, 
Check List Miocene Foss, p. 6. 
Arca Marylandica Heilprin: Proc. Acad. Nat. Sci., Phil. 1887, pp. 398 and 402. 
“Shell oblong, compressed, thin, with very numerous radiating granu- 
lated strize; beaks not prominent; base much contracted or emarginate 
anterior to the middle; posterior side dialated, the superior margin very 
oblique and emarginate; extremity angulated, and situated nearer to the 
line of the hinge than to that of the base; cardinal teeth minute, except 
toward the extremities of the cardinal line, where they are comparatively 
very large and oblique; inner margin entire.” 
This seems to have been a not very abundant species over the region 
of New Jersey, as there are but two specimens of it among the collections 
sent me; one small and one fully grown left valve, the latter imperfect. 
When young it somewhat resembles Striarca centenaria of the same size; 
but may be distinguished by its less depth, more emarginate basal margin, 
longer posterior hinge alation, and by the narrower hinge plate and less 
distinct teeth. In the adult stage the differences are so great that no mistake 
‘an be made. The strie on the posterior portion of the shell, especially 
those along the umbonal slope, are very generally duplicate in character 
and those on the anterior end are more distant than on any other part. 
On well-preserved surfaces the granulations of the striz on the anterior 
portions of the shell become distinct asperities. 
Locality: From the gray marls at Shiloh, N. J. Both of the specimens 
mentioned are from the collections of the National Museum. 
