NO. 3 UPPER CAMBRIAN TRILOBITE FAUNAS — RASETTI 13 



Oder's collection No. 14, a short distance below the preceding : 



Aphelaspis arsoides 

 Aphelaspis tumijrons 



The above unit is underlain by a thick shale interval with minor 

 siltstone, limestone, and limestone conglomerate layers. Some of the 

 limestone beds are lenticular. The base of this shale rests on massive 

 limestone as in the sections of the Rogersville area. The thickness of 

 the limestone cannot be accurately measured but seems to be much 

 less than in the vicinity of Rogersville. 



The following collections were all made from thin limestone beds 

 in the shale unit. 



Collection cns/16 (= Oder's collection No. 13), 

 about 100 feet below top of shale : 



Aphelaspis camiro c 



Aphelaspis laxa r 



Aphelaspis quadrata c 



Collection cnq/16, about 2 feet below the preceding : 



Aphelaspis walcotti 



Glaphyraspis ornata 



Glaphyraspis declivis 

 Collection cnr/16, about 2 feet below the preceding: 



Aphelaspis walcotti cc 



Glaphyraspis ornata r 



Collection cnn/16, about 145 feet below top of shale : 



Amiaspis erratica 



Amiaspis obsolescens 



Coosia alethes 



Crepicephalus buttsi 



This section affords a good sequence of Aphelaspis faunules and 

 confirms the order of the species of this genus observed in other sec- 

 tions. The lowest faunule belongs to the Crepicephalus zone. It is 

 notable for the presence of the genus Amiaspis. 



Thorn Hill. — The Nolichucky formation exposed in the Thorn Hill 

 section, measured by Hall and Amick, is not particularly fossiliferous. 

 The author collected from limestone beds interstratified with shale in 

 the lower portion of the formation (Cedaria zone, loc. cnd/13) the 

 following species : 



Cedaria tennesseensis 



Kormagnostus simplex 

 Menomonia, sp. undet. 

 Norwoodella walcotti 



Washburn. — A richly fossiliferous and excellently exposed section 

 of the beds of the Aphelaspis zone was measured in a cut of the 

 Southern Railway about a mile north of Washburn, The locality is in 



