48 PALBONT(3LO(lY OF NEW JEESEY. 



Genus BARB ATI A Gray. 



. Bakbatia Marylandica. 



Plate VII, tigs. 2-4. 



Byssoarcu Marylandica Oourad: Miocene Fos.s., p. .54, PI. xxix, fig. 1. 



Barbatia Marylandica Coni-ad: Proc. Acad. Nat. Sci., Phil., 1862, p. 580; Meek, 



Cheek 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 stri*; beaks not prominent; base much contracted or eniarginate 

 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 mav be distinguished bv its less depth, more emarginate basal margin, 

 longer posterior hinge alation, and l)v the narrower hinge plate and less 

 distinct teeth. In the adult stage the differences are so great that no mistake 

 can be made. The stripe on the posterioi- portion of the shell, especially 

 those along the uraboual slope, are A'ery generallv 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. 



Loraliti/: From the gray marls at Shiloh, N. J. Both of the specimens 

 mentioned are from the collections of the National Museum. 



