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



ManueVs Brook Section. 



1. Coarse conglomerate, in massive layers. The material 

 next to the gneiss vai'ies in size, from bowlders of quartz 

 and gneiss six feet in diameter, down to small pebbles, 

 and in the upper beds from pebbles to fine sand 35 



Strike, N. 80° E. (Magnetic) ; Dip. 12° to 13° N. 



2. Irregular beds of calcareous sandstone, siliceous limestone 

 and greenish-colored argillaceous shale, covering the irreg- 

 ular upper surface of the conglomerate 0-25 



Fossils: — Obolella Atlantica, Hyolithellus micans Bill- 

 ings, Hyolithellus? , n. sp., Hyolithes princeps Billings, 

 Hyolithes impar Ford, -Hyolithes quadricostatus, S. and F. 

 and two undescribed species, Gasteropoda n. gen., n. sp., 

 Scenella reticulata Billings, Stenotheca rugosa, var. acuta- 

 costa, n. var., Stenotheca rugosa, var. erecta, n. var., Steno- 

 theca rugosa, var. losvis, n. var., Stenotheca rugosa, var. 

 pauper a Billings, Platyceras primazvum Billings, Micro- 

 discus Selena, n. sp., Microdiscus speciosus Ford, Micro- 

 discus, sp. ?, Olenellus Broggeri Walcott, Avalonia Man- 

 uelensis, n. gen., n. sp., Ptychoparia Morrisi, n. sp., Agrau- 

 los (S.) strenuus Billings, Agraulos (S.) strenuus, var. 

 nasutus, n. var., Solenopleura bombifrons Matthew, Solen- 

 opleura, n. sp. 



3. Greenish argillaceous shale, conformably subjacent to 2.. 40 



4. Reddish-colored argillaceous shale 4 



5. Calcareous sandstone, with pinkish limestone in irregular 

 masses 2 



6. Green argillaceous shale with thin layers of hard, dark, 

 ferruginous sandstone, interbedded at several horizons 270 



Strike, N. 80° E. ; Dip. 12° N". 



Fossils : — Near the base the head of an Olenellus was 

 found, also fragments of an Agraulos or Ptychoparia. At 

 218 feet from the base a layer of pinkish limestone con- 

 tained the head of an Agraulos, like A. strenuus, and 

 many fragments of trilobites. Fifty-two feet higher up 

 quite an abundant fauna was found, and the following 

 species were collected : Lingulella sp. a, Acrothele Mat- 

 thewi Hartt (sp.), Agnostus sp. a, Agnostus sp. d, Par- 

 adoxides Hicksi Salter, Conocoryphe Matthewi Hartt (sp.), 

 Liostracus sp. a. 



7. Dark argillaceous shales with thin layers of limestone and 

 sandstone, at various horizons 295 



Fossils : — Zone a. From 10 to 20 feet feet from the base 

 the following species were collected: Lingulella sp. a, 

 Linnarssonia miser a Billings, Acrothele Matthewi Hartt 

 (sp.), Hyolithes sp. a, Agnostus, 3 sp., a, b, c, 3£icrodiscus 

 punctatus Salter, Paradoxides Hicksi, Conocoryphe (C) 

 Matthewi Hartt (sp.), Conocoryphe elegans Hartt (sp.), 

 Agraidos socialis Billings, Liostracus tener Hartt (sp.). 



