61 



SECTION No. 15.— EAST SIDE OF RIVER, NORTH OF BRIDGE IN SECTION No. 14 



(480 to 504) 

 Meadowvale Member: Thickness 



feet 

 (4) Hard, compact shale alternating with impure, argillaceous lime- 

 stone and soft clay shale. The following fossils were found: Hebertella 

 occidentalism Rafinesquina alternata, Rafinesquina alternata subcircularis, 



Zygospira modesta, Byssonychia sp 6 



(3) The Columnaria reef with: Stromatocerium huronense, Colum- 

 naria alveolata, Columnaria calicina, Tetr odium approximatum, Hebertella 

 occidentalis, Platystrophia sp 2 



Streetsville Member: 



(2) Interbedded shale and limestone with: Hebertella occidentalis, 

 Platystrophia clarkesvillensis , Columnaria alveolata 2V2 



(1) Talus-covered interval extending to water level 13'/2 



Horizon No. 2 is regarded as the upper part of the Bythopora meeki zone and is 

 included in the Streetsville member, since the Columnaria reef which is an easily- 

 recognized horizon is made the base of the Meadowvale member. 



SECTION No. 16.— WEST SIDE OF RIVER, 100 YARDS NORTH OF CASTLER'S 



BRIDGE (495 to 505) 

 Meadowvale Member: Thickness 



feet 



(2) The Columnaria reef made up of the coralla of Columnaria 

 alveolata, Columnaria calicina, Tetradium approximatum, and Stromatocerium 

 huronense. The two bryozoans, Rhombotrypa quadrata and Constellaria 

 polystomella, are very numerous. The following fossils also occur: 

 Hebertella occidentalis, Platystrophia clarkesvillensis, Rafinesquina 

 alternata, Zygospira modesta, Hallopora cf. onealli, Homotrypella hospitalis, 

 Fenestella sp., Opisthoptera fissicosta, Byssonychia sp., Cyclonema sp., 

 Liospira cf. helena 6V2 



Streetsville Member: 



(1) Alternating beds of shale and limestone. The shale is ripple- 

 marked, some cross ripples being noticed. Fucoids are numerous, and 

 Columnaria alveolata is found 2'/2 



Horizon No. 1 is herein included in the Bythopora meeki zone. Near the 

 northern end of the section the Columnaria reef becomes much thinner. At 

 this end, also, a bed of limestone occurs about three feet above the water-level, 

 (500) which yields numerous examples of the gastropods, Lophospira bowdeni 

 and Lophospira tropidophora. Platystrophia clarkesvillensis, Homotrypella 

 hospitalis, Hebertella occidentalis, and Byssonychia sp. also occur. 



SECTION No. 17.— WEST SIDE OF RIVER, ONE MILE NORTH OF CASTLER'S 



BRIDGE (495 to 505) 

 Meadowvale Member: Thickness 



feet 



(3) Alternating beds of limestone, clay shale, and argillaceous sand- 

 stone. The following fossils are found: Columnaria alveolata, Hebertella 

 occidentalis, Platystrophia cf. clarkesvillensis, Zygospira modesta, Rafines- 

 quina alternata, Rafinesquina alternata subcircularis, Byssonychia sp., 

 Clidophorus fabula, Modiolopsis concentrica, Opisthoptera fissicosta, Pterinea 

 demissa, Whiteavesia pholadifotmis, Cyrtolites ornatus, crinoid columns. ... 7 



(2) The Columnaria reef with: Columnaria alveolata, Columnaria 

 calicina, Tetradium approximatum, and Stromatocerium huronense 2 



Streetsville Member: 



(1) Alternating beds of soft shale and arenaceous shale, extending to 

 water-level. The arenaceous shale shows beautiful cross ripple marking. 

 Columnaria alveolata occurs 1 



