Maryland Geological Survky 547 



from L. ligca and L. melie in its more ovate form. Associated with the 

 larger shells are many sm'aller individuals M'hich are considered the young 

 of this species. They are less ovate, not being much if any wider in 

 front, a feature shown to be characteristic of the young individuals by 

 the concentric lines on the older shells. This species is locally abundant 

 in the western sections at the base of the Parkhead member. 



Occurrence. — Jennings Formation, Parkhead Member. Williams 

 Road east of Cumberland, 1393, abundant; 2^4 miles southeast of Cum- 

 berland ; road 1 mile north of Eocky Eun, AVest Virginia. 



Collection. — Mar}dand Geological Survey. 



LiNGULA ligea Hall 



Plate XLVIT, Figs. 6, 7 



Lingula ligca Hall, 1860, 13th Rept. N. Y. State Cab. Nat. Hist., p. 76. 

 Lingula ligea Hall, 1867, Pal. of N. Y., vol. iv, p. 7, pi. 1, fig. 2. 

 Lingula ligea var. Hall, 1867, Pal. of N. Y., vol. iv, p. 8, pi. ii, flg. 8. 

 Lingula ligea Grabau and Shlmer, 1909, N. Amer. Index Fos. vol. i, p. 197, 

 fig. 229. 



Description. — ■" Shell narrow elliptical ; length equal to twice the width; 

 sides regularly curving ; extremities subequal ; margins of the valves thick- 

 ened. Surface marked by fine concentric stria^, and by a few obscure or 

 obsolete radiating strife. The more convex valve shows, along the inner 

 margin, a narroM' shallow groove as if the edge of the opposite valve 

 closed just within its margin." Hall, 1867. 



The variety is described as "larger, the sides somewhat straighter; 

 while the cardinal extremity is not so rounded, and slopes in nearly a 

 right line on each side of the beak." ' The individuals observed coitcs- 

 pond well with the form described by Hall as Lingula ligea var. save that 

 they are somewhat smaller. 



Occurrence. — Jennings Formation, Ithaca Fauna. Hancock, 1149 

 to 1274 rare, 1564 to 1599 ? abundant. The latter specimens were found 

 loose on the road. They occur in red sandstone similar to that forming 



' Pal. of N. Y., vol. iv, p. S. 



