16 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148 



collectors, and several of the fossils in the U.S. National Museum 

 collections were used as types by Walcott and Resser (U.S.N.M. 

 locality 120). In these early collections fossils from the Crepicephalus 

 and Aphelaspis zones were indiscriminately mixed. Bridge (1956) 

 gave a description of the section in which, however, many intervals 

 were stated to be covered. His collection No. 2804, from which the 

 new species Aphelaspis hridgei is described herein, was made at this 

 locality. 



The general lithology of the Nolichucky is very similar to that 

 described for the Rogersville Big Creek section. Thicknesses were not 

 measured because of the unfavorable topography and incomplete expo- 

 sures. The lower Nolichucky shale is followed by a massive limestone 

 unit that bears fossils at least in its upper portion. Fossils of the 

 Crepicephalus zone occur (loc. cnn/5) 30-40 feet below the top of the 

 limestone (Tricrepicephalus thoosa, Meteoraspis sp.). However, the 

 top of the massive limestone belongs in the Aphelaspis zone. Crystal- 

 line lenses in aphanitic limestone in the uppermost 1 foot of the unit, 

 as well as limestone lenses in the lower few feet of the overlying shale, 

 yielded collection cns/2. The species observed are : 



* Aphelaspis arsoides c 



* Aphelaspis inertnis r 

 Aphelaspis tumifrons cc 

 Cheilocephalus, sp. undet. r 

 PseudagnosHis communis r 



Comparison with the faunules of the Big Creek, Three Springs, and 

 Washburn sections indicates that the above faunule is fairly high in 

 the middle portion of the Aphelaspis zone. The U.S. National Museum 

 collection 120 includes the types of Aphelaspis camiro, A. laxa, and 

 A. quadrata which, as it appears from other evidence, are somewhat 

 older than the species listed above. Collection 2804 of the U.S. Geo- 

 logical Survey yielded the types of Aphelaspis hridgei, unknown from 

 other localities. Its association with Blountia bristolensis and Glaphyr- 

 aspis ornata, species that were found only in the basal beds of the 

 Aphelaspis zone at other localities, shows that this collection was 

 made from beds still lower than those yielding Aphelaspis camiro, A. 

 laxa, and A. quadrata. Unfortunately, the portion of the massive lime- 

 stone with interbedded shale intervals, from which all these fossils 

 are presumed to come, is now poorly exposed and shows only apha- 

 nitic, unfossiliferous beds. 



The massive limestone is overlain by 40 to 50 feet of shale, the lower 

 portion of which contains the rare limestone lenses mentioned above. 

 The shale is in turn overlain by the usual limestone ribboned with 



