242 SYSTEMATIC PALEONTOLOGY 



beyond the width of the shell; area narrow, dorsal foramen extending 

 to the beak." Hall, 1847. 



Occurrence. MARTIXSBURG SHALE (Orthorhynchula bed at the top of 

 the Fairview division). Tuscarora Mountain, one and one-half miles 

 southeast of McConnellsburg, Pennsylvania. The types of this species 

 were obtained in the upper part of the Fairview formation at Cincinnati, 

 Ohio. 



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



PLECTORTHIS PLICATELLA Hall var. 

 Plate LIV, Figs. 15-16 



Description. The typical form of this species occurs in the lower part 

 of the Maysville group at Cincinnati, Ohio, and vicinity. The upper part 

 of the Martinsburg shale in Pennsylvania has afforded brachiopod so 

 close to P. plicatella that it cannot be considered more than a variety. 

 Unfortunately the preservation of these specimens is not good enough to 

 allow this variety to be distinguished. A description of Plectorthis 

 plicatella is given above. 



Occurrence. MARTINSBURG SHALE (Eden division). Jordans Knob, 

 one and one-half miles northeast of Fort Loudon, Pennsylvania, has fur- 

 nished the Eden form here regarded as a variety. 



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



Genus DALMANELLA Hall and Clarke 

 DALMANELLA TESTUDINARIA (Dalman) var. 



Plate L, Figs. 9, 10 



Orthis testudinaria Dalman, 1828, Kongl. Sverrska Vet.-Akad. Handl., p. 115, 



pi. ii, fig. 4. 

 Dalmanella testudinaria Weller, 1903, Geol. Surv. New Jersey, Pal., vol. iii, 



p. 155, pi. x, figs. 1,2; p. 216, pi. xvi, figs. 4, 5. 



Description. " Adult shells subcircular and the younger ones trans- 

 versely subelliptical in outline; hinge-line less than the greatest width: 

 cardinal angles rounded, lateral and anterior margins broadly rounded, 

 though the extreme front of the shell is sometimes straight for a short 



