378 C. D. Walcott — Position of the Olenellus Fauna. 



I next proceeded to Newfoundland, where there appeared to 

 be a prospect of settling the question for America, by discov- 

 ering the two faunas in the same stratigraphic section. 



The first section examined was that beneath Topsail Head, 

 Conception Bay. It was found to be as described by Mr. 

 Alexander Murray.* The limestone at the base is separated 

 from the " Huronian " rocks by a fault line. Over the lime- 

 stone a hundred feet or more of greenish shale completes the 

 section. 



In the limestone I found Obolella AtlanUca, Kutorgina 

 Labradorica, Scenella reticulata Billings, Hyolithellus micans 

 Billings, Hyolithellus micans, var. rugosa, Hyolithes princ&ps 

 Billings, II. impar Ford, Microdiscus speciosus Ford, Micro- 

 discus, sp. undet., Olenellus Broggeri, n. sp., Avalonia Man- 

 uelensis, n. gen., n. sp., Solenopleura bombifrons Matthew, 

 Agraidos (8.) strenuus Billings, Agraulos ($.), n. sp. 



In the superjacent green shales a few fragments of a trilobite 

 were observed that indicated, by a portion of the glabella and 

 eyelobe, a large species of Paradoxides. The evidence here 

 obtained being somewhat inconclusive, the section at Brigus 

 Head, on the west side of Conception Bay, was next examined 

 and found to be essentially the same as that at Topsail Head, 

 with the addition of a greater thickness of green and red shales 

 above the limestone, and a sandy deposit beneath the limestone 

 which rested unconformably against the "Huronian." The 

 limestone series is divided into three bands. I a the lowest, 

 a specimen of Hyolithes impar was found similar to that in the 

 limestone at Topsail Head, associated with fragments of a 



species of Olenellus (0. Broggeri), Microdiscus and 



Ptychoparia (?) . In the second bed of limestone frag- 

 ments of trilobites were seen ; and in the upper bed Olenellus 

 Broggei'i and Agraulos strenuus, were observed, the latter in 

 great abundance. No fossils were discovered in the superja- 

 cent slates. 



There remained but one section, known to me, where the 

 Cambrian rocks rested on the " Huronian " gneiss and the 

 stratigraphic succession of the beds continued unbroken up to 

 the unquestioned Paradoxides horizon. This was on Manuel's 

 Brook, one-and-a-half miles west of Topsail Head. A coarse 

 conglomerate rests directly and unconformably upon a syenitic 

 gneiss. Along the line of the brook the conglomerate is con- 

 formably subjacent to a belt of greenish shale which is suc- 

 ceeded by a band of red shale subjacent to a thin stratum of 

 limestone, which is followed by greenish shales, and these in 

 turn by black shales carrying an abundant Paradoxides fauna. 

 This section being conformable, a careful search was made for 



* Rept. Geol. Survey, Newfoundland, 1868, Reprint of 1881, p. 154. 



