Maeylaxd Gkological Survey 413 



Occurrence. — Oriskany Formation, Eidgely Member. Cumber- 

 land, Washington County, abundant. 



Collections. — Maryland Geological Survey, American Museum of 

 Natural History, TJ. S. National Museum. 



Spirifer murchisoxi var. marylandicus n. var. 

 Plate LXX, Figs. 6, 7 



Description.- — This variety may be distinguished from the species by the 

 greater number of plications and their greater angularity, and by the fold 

 and sinus. The plications in the variety vary in number from eight to ten 

 on each side of the fold, while in the Maryland specimens of S. nmr- 

 chisoni the range is from six to eight. 



Length 3.2 cm. ; width about 4 cm. 



Occurrence. — Oriskany Formation, Eidgely Member. Cumberland, 

 abundant. 



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



Spirifer iiartleyi n. sp. 

 Plate LXX, Figs. 8-10 



Description. — -This species resembles S. murchisoni in its form and 

 the few plications, of which it has from five to six on each side of the fold 

 and sinus. However, it is less alate and gibbous and never has the wide 

 angulated fold and sinus of that species, but rather of 8. tribulis, in which 

 it is narrow, low, and rounded. 8. Jiartleyi differs from all the Maryland 

 species of this genus by its depressed and strongly incurved ventral beak, 

 an exaggerated character of 8. cyclopterus. In a general way this species 

 may be regarded as a very large 8. trihnJis in which divergence has taken 

 place by the decided angulation of the plications, a slight reduction in 

 their number, with a more depressed and more hooked ventral beak. 



Length about 3 cm. ; width about 4 cm. 



Occurrence. — Oriskany Formation, Eidgely JMember. Cumberland. 



Collection. — U. S. National Museum. 



