48 PALEONTOLOGY OF NEW JERSEY. 



Genus BARBAT1A Gray. 



Barbatia Marylandica. 



Plate vn, figs. 2-4. 



Byssoarca Marylandica Conrad : Miocene Foss., p. 54, PI. xxix, fig. 1. 



Barbatia Marylandica Conrad: Proe. Acad. Nat. Sci., Phil., 1862, p. 580; Meek, 



Check List Miocene Foss, p. 6. 

 Area Marylandica Heilprin: Proc. Acad. Nat. Sci., Phil., 1887, pp. 398 and 402. 



" Shell oblong, compressed, thin, with very numerous radiating granu- 

 lated stride; 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 

 can be made. The striae 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 striae 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. 



