Mahylaxd Gkological Sukvey 583 



Occurrence. — Jennings Formation, Wooumont Member, Ithaca 

 FAt'iXA. Two miles west of Pawpaw, West Virginia, 1340, 1388; 

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

 T.ittlo Orlciinp, 14 Ki; Wdndiiioiit. 10-24 ahundant. 1032 common, 1067; 

 National Road, M'est of Tonoloway Eidge, abundant; Hancock, 1274, 

 1149 to 1274 abundant; Millstone, 1057, 1122 abundant, 1148 abundant; 

 Berkeley Springs, West Virginia, 712 common, 1058, 1080, 1163 com- 

 mon : Yellow Springs Eoad, West Virginia, 629 abundant, 6(i5 abundant. 



Collection. — Maryland Geological Sui-vey. 



Genus PUGNAX Hall and Claike 

 PUGNAX PUGNUS VAR. AI.TUS (Calviu) 



Plate LIV, Figs. 17-22 



RhynclwneUa alta ' Calvin, circa 1875, privately distributed paper with 



figures. 

 Rhynchonella punniis var. alta Williams, 1S9(I, Bull. Geol. Soc. Amer., vol. i, 



pi. xii, figs. 5-7. 

 Pugnax alius Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, p. 203, pi. Ix, 



figs. 1-5. 



Descripiion. — Shell triangular to elliptical or ^ubcircular. Slightly 

 transverse or length and breadth subequal. Ventral valve depressed into 

 a sinus which begins near or slightly posterior to middle of shell and 

 becomes deep towards front of shell, umbo erect or slightly incurved, 

 extending much l)eyond that of dorsal valve. Dorsal valve much more 

 convex than ventral, bearing a fold which becomes prominent towards 

 front. Surface ornamented by coarse plications of which 2 usually occur 

 in sinus, 3 on fold and about 4 on each lateral slope. The plications 

 become obsolete towards umbo which is smooth. In some cases they are 

 confined to marginal portion, on others they extend % length of shell. 



Tlic variety altiis was named by Calvin but does not appear to have been 

 described by him. It differs from the typical f(n'm in being much less 

 transverse. 



Length 18 mm.; width 20 mm. 



' Bull. Geol. Soc. Amer.. vol. xxiii. 1912, p. C. 



