ilARYLAXD Geological Survey 399 



vertical ventral cardinal area ; the valves are more appressed, causing the 

 visceral area to be shallower, and the lamellse are devoid of marginal 

 spines. 



S. suhmucronaius is nothing more than young specimens of S. cumher- 

 Jandice. Both have the same general expression, and while the former has 

 at times fewer plications, yet this difference is due either to age, or size, or 

 individual peculiarities. 



Mr. Andrews, who furnished Hall's material, collected most of his 

 Oriskany fossils in the quarries on Green Street, back of the German 

 Lutheran Church, Cumberland. They are no longer worked but are now 

 built over by the church and neighboring houses. Although S. cumber- 

 landice was gathered here, it is significant that none of the local collectors 

 have this species in their collections. This shows that these quarries are of 

 another horizon than those now furnishing fossils, and tliis is borne out by 

 their geological structure, indicating that they are lower down in the 

 Oriskany. S. cumierlandice seems to be restricted to a horizon about 150 

 to 200 feet above the base of the Oriskany. 



Length 1.3 to 2.4 cm. ; width 2.2 to 4.6 cm. 



Occuirence. — Oriskany Formation, Eidgely Mejiber. The original 

 material came from tlie quarries back of the Gennan Lutheran Church on 

 Green Street, Cumlierland, DeviFs Backbone, east side of Nicholas Moun- 

 tain, Collier's Euu. 



Collections. — Maryland Geological Survey, U. S. National Museum. 



Spirifer modestus Hall 



Plate LXVITI, Figs. 17-22 



Spirifer modestus Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 203, pi. xxviii, 

 figs, la-e, 1861. 



Description. — " Shell small, subglobose. Ventral valve very gibbous 

 near the middle and towards the beak, having a shallow undefined sinus 

 extending from the beak to the front : beak prominent, acutely pointed, 

 incurved. Dorsal valve regularly convex, semicircular or subtriangular : 

 extremities rounded, sometimes an undefined mesial elevation : beak 

 scarcely extending above the hinge-line, not incurved ; hinge-line very 



