of the Devonian of '" Western Tennessee. 753 



tion to the Maecuru fauna of South America are Stro- 

 pheodonta cf . blainvillei, Anoplia nucleata, Chonetes hud- 

 sonicus mut. camdenensis, Amphigenia curta, Spirifer 

 duodenarius, Leptocoelia flabellites, and Actinopteria 

 communis. 



Succeeding the Clear Creek in Illinois, the Grand 

 Tower (Onondaga) formation is about 150 feet thick. 

 The characteristic and widespread coral fauna does not 

 appear here until about the middle of the formation. 

 Savage's studies have led to the conclusion that its 

 appearance marks the first confluence of this southern 

 embayment with the northeastern one whence the corals 

 seemingly came. Both the corals and cephalopods, he 

 believes, are present in New York in lower strata equiva- 

 lent to the lower half of the Grand Tower formation. If 

 this be true, the inclusion of the Clear Creek (and Cam- 

 den) chert in the Ulsterian series makes a thickness of 

 over 300 feet of strata in this southern embayment before 

 the advent here of the coral fauna. The incursion of this 

 embayment must therefore have taken place very early 

 in the Middle Devonian, and the Camden (and Clear 

 Creek) chert may be partially at least the equivalent of 

 the Esopus and Schoharie grits of New York. 



Pegram limestone. — This thin formation of heavy- 

 bedded white limestone was named by Foerste (1901) for 

 the village of Pegram, Tennessee. It attains a maximum 

 thickness of 12 feet at this locality, but thins out eastward 

 to 3 feet near Newsom. Only three widely separated 

 remnants of the formation are known, the first being the 

 small area about Pegram where several outcrops occur, 

 the second fully 50 miles west at the "whirl" on Buffalo 

 River 4 miles north of Bakerville, and the third in Wayne 

 County near Fortyeight P. O. 



The exposure 3 miles west of Newsom has yielded the 

 diagnostic Onondagan blastoid, Nucleocrinus verneuili 

 and in addition Stropheodonta demissa, 8. perplana, 

 Rhipidomella penelope, and Nucleospira concinna. The 

 formation at the locality on Buffalo River 4 miles north 

 of Bakerville is replete with Onondaga corals, among 

 which are Cyathophyllum rugosum, species of Helio- 

 phyllum, Blotlirophyllum, CystipliyUiim, Cyatliophyllum, 

 etc. 



The fauna clearly indicates an equivalence with the 

 Jeffersonville limestone of Indiana and Kentucky, of 



