CAMBRO-ORDOVICIANS LIMESTONES 707 



Rhabdaria, cf. R. fragilis Billings. Maclurea affinis. 



Calathium sp. undet. Eccyliopterus. 



Orthis wemplei ? E. triangulus. 



Ophileta complanata. Bathyurus near B. conicus. 



In the middle of the formation two faunas have been distinguished. 

 The lower one, characterized by horn-like Opercula, small Isochilina, 

 Hormotoma artemesia, and large thin-shelled Maclurea, occurs in 

 both quadrangles and good collections were made at Licking Creek 

 and near McConnellsburg. 15 species were collected of which the 

 following have been tentatively determined : 



Orthis cf. electra. Eccyliopterus, cf. triangulus. 



Maclurea affinis. Isotelus canalis. 



Horn-like opercula of an otherwise Bathyurus cf. conicus. 



unknown gasteropod for which B. caudatus. 



Mr. Ulrich suggests the generic Amphion cf. salteri. 



name Ceratopea. Leperditia cf. Primitia gregaria 

 Liospira canadensis. Whitfield. 



The upper fauna of the middle division, characterized by Syn- 

 trophia lateralis and found only at Stoufferstown, is as follows : 



Syntrophia lateralis. Liospira cf. laurentina. 



Maclurea? sordida. Orthoceras cf. primigenium. 



In the upper part of the formation, which is characterized by high- 

 spired turritelloid gasteropods and by Ophileta disjuncta, 17 species 

 have been collected from the quarry at Stoufferstown, and the fol- 

 lowing tentatively identified by Mr. Ulrich : 



Orthis ( ? Dalmanella) electra. Hormotoma gracilens. 



Maclurea cf. M. oceana. Lophospira cf. Murchisonia gregaria 



Ophileta ? disjuncta. Billings. 



Solenospira cf. prisca. ' Cyrtocerina cf. mercurius. 



Turritoma acrea? Trocholites internestriatus. 



Mr. Ulrich, who determined all the fossils described under this 

 and succeeding headings, correlates the foregoing lists with the Beek- 

 mantown of New York, and that name is therefore applied to the 

 formation. 



STONES RIVER LIMESTONE 



Above the Beekmantown is a considerable thickness of very pure 

 limestones with occasional magnesian layers. The greater portion 

 of the limestone that is burned for lime in this area is obtained from 



