154 



Annals of the Carnegie Museum. 



Tail-valve ovate, wider in front than behind. Jugal ridge narrow, 

 sharply delimited by narrow lateral furrows. The mucro is low, but 

 sharp, situated close to the posterior margin. Posterior sinus very shal- 

 low, indented by a narrow groove. Surface marked by lines of growth 

 and \ery fine granules. 



As the two valves here described were found disconnected it is not 

 certain that they belong to the same species. In any case the tail-valve 

 is to be considered the holotype and the other valve a paratype. 



The tail-\'alve of this species differs from that of Glaphurochiton car- 

 boniferous in having the mucro much further back, its position being 

 almost median in the species described by Stevens. The surface of the 

 new species is very finely granulose, while in the other form the granules 

 are large. 



Locality. — The two specimens which represent this species were found 

 in the Vanport limestone in the abandoned quarry between New Castle 

 and New Castle Junction, Pa. 



Distribution of Species. 



Fusulinella sp 



Lophophyllum profundum (Milne-Edwards & Haime) 



Carnpophyllum torquium (Owen) 



Cyathaxonia dislorta Worthen 



Ceriocrinns craigi (Worthen) 



Ceriocrinus sp 



Hydreionocrinns sp 



Columns and plates of crinoids 



Seplopora biserialis (Swallow) 



Tharnniscus sevilletisis Ulrich 



Rhomhopora nickelesi Ulrich 



Lingula umbonata Cox 



Orbicidoidea missoiiriensis (Shumard) 



Orbicidoidea convexa (Shumard) 



Orbiculoidea planodisca sp. nov 



Crania modesta White and St. John 



Rhipidomella pecosi (Marcou) 



Derby a crassa (Meek and Hayden) 



Chonetes mesolobus Norwood and Pratten 



Chonetes verneuilanus Norwood and Pratten 



Chonetes granidifer Owen 



Productus semireticulatus (Martin) 



Productus cora d'Orbigny 



Productus nebrascensis Owen 



Productus punclatus (Martin) 



Productus nanus Meek and Worthen 



Productus pertenuis Meek 



