5'J2 Systematic Paleontology — Upper Devonian 



This is a common species in the Ithaca fauna. It is less frequent in 

 the Parkhead and rare in the Chemung. 



Occurrence. — Jennings Forimation, Che:mung Meiiber. Between 

 Oaldand and Deer Park; Town Creek, 2033, 2228; Pennsylvania state 

 line, west of Green Eidge, in upper Tropidoleplus zone. Parkhead 

 Member. Allegany Grove 850; Eocky Run; Williams Eoad, on Polish 

 Mountain, 1660; 2 miles north of mouth of Town Creek, 1842; Sideling 

 Hill Creek 21/^ miles above mouth. Woodmont ]\Iember, Ithaca Fauna. 

 Two miles west of Pawpaw, "West Virginia, 1340 abundant, 1388 com- 

 mon; east of Little Orleans, 1446; Fifteenmile Creek, 1 mile above Little 

 Orleans, 1446 abundant; Woodmont, 1024, 1032 common, 1067; National 

 Eoad M-est of Tonoloway Eidge; Hancock, 1149 to 1274 common; Mill- 

 stone, 1122 comiiKm; Berkeley Springs, West Virginia, 1163 abundant; 

 Yellow Springs, West Virginia, 629 abundant, 665. 



Collection. — ^Maryland Geological Surv^ey. 



Genus RETICULARIA McCoy 



Eeticularia l.evis (Hall) 

 Plate LVI, Figs. 4-6 



Delthyris Iwvis Hall, 1843, Geol. N. Y., Rept. 4th Dist., p. 245, fig. 1. 

 Spirifer Iwvis Hall, 1867, Pal. of N. Y., vol. iv, p. 239, pi. xxxix, figs. 1-12. 

 Eeticularia Iwvis Schucliert, 1897, Bull. U. S. Geol. Survey, No. 87, p. 343. 

 Recticularia la'vis Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 

 339, fig. 432. 



])psrrijttion.: — "Shell ventricose, snbcircnlar or semiclliptical. with the 

 cardinal extremities rounded; length and breadth as two to tlirce, or three 

 to four; not plicate. 



" Ventral valve ventricose ; the greatest convexity above the middle, 

 from whence it curves gently to the base and suddenly towards the beak, 

 which is abruptly attenuate and arching over the area: sinus variable, 

 often shallow, gently concave and scarcely defined : sometimes l)ecoming 

 deep, suliangular, and very In'oad in the lower part. Area extending to 

 the hinge-extremities, of moderate height at the sides and rising abruptly 

 towards the middle; foramen partially closed by an arching, very convex 

 pseudo-deltidiiun. 



