Maryland Geological Survey 537 



Collections. — Marvin ml Geological Survey, Philadelphia Academy of 

 Natural Sciences, New Jersey Geological Survey, U. S. National Museum. 



Outside Distribution. — Matawan Formation. Merchantville clay marl, 

 New Jersey. 



Subgenus BARBATIA Gray 

 [Proc. Zool. Soc. London, 1847, p. 197] 



Type. — Area barbatia Linne. 



Shell equivalve; hinge teeth numerous, small and vertical beneath the 

 umbones, becoming larger and more oblique distally; ligamental area nar- 

 row; cartilage grooves angular, concentric. 



Arc a (Baebatia) saffordi Gabb 

 Plate XXI, Fig. 3, 4 



Area saffordi Gabb, 1860, Jour. Acad. Nat. Sci., Phila., 2d ser., vol. iv, p. 



397, pi. lxviii, fig. 38 (incorrectly cited as 37). 

 Area saffordi Meek, 1864, Check List Invert. Fossils N. A., Cret. and Jur., 



p. 9. 

 Trigonarea saffordi Cook, 1868, Geol. of New Jersey, p. 725. 

 Trigonarca (Breviarca) saffordi Conrad, 1872, Proc. Acad. Nat. Sci., Phila., 



p. 55, pi. ii, fig. 3. 

 Trigonarca (Breviarca) saffordi Gabb, 1875, Kerr, Rept. Geol. Survey of 



North Carolina, vol. i, App. A., p. 3. 

 Breviarca saffordi "Whitfield, 1885, Mon. U. S. Geol. Survey, vol. ix, p. 87, 



pi. xii, figs. 11, 12. 

 Area saffordi Johnson, 1905, Proc. Acad. Nat. Sci., Phila., p. 9. 

 Breviarca saffordi Weller, 1907, Geol. Survey of New Jersey, Pal., vol. iv, 



p. 404, pi. xxx, figs. 21-24 (casts only). 

 Breviarca saffordi Grabau and Shinier, 1909, N. A. Index Fossils, vol. i, 



p. 408, fig. 527. 



Description. — " Gibbous, nearly equilateral ; beaks small, overhanging 

 the area ; umbones broad ; area narrow and transversely striate ; anterior 

 margin narrower and straighter than the posterior, which is regularly 

 curved; surface marked by obscure radiating and concentric lines; hinge 

 rather broad, curved ; teeth large. 



" Dimensions.- — Length .2 in. ; width .26 in. ; height of valve .1 in. 



" Locality. — Hardeman County, Tennessee. Prof. Safford. Also found 

 in the Ripley group of New Jersey." — Gabb, 1860. 



