(4) Shale with a few thin layers of limestone containing fragments of 

 Isotelus sp 8'/2 



(3) The bryozoan reef, in places a single massive bed of limestone, 

 at other places separated into two or three beds by thin layers of shale. 

 It varies in thickness from six inches to 18 inches and is characterized by 

 the abundance of Heterotrypa definita. Examples of Rafinesquina alternata 

 are numerous and the following species also occur: Rafinesquina alternata 

 subcircularis, Catazyga headi, Hebertella occidentalism Hallopora. sub- 

 nodosa, Hallopora cf. onealli, Byssonychia sp., Modiolopsis sp. By wye 

 level the under side of this reef, where it first outcrops east of the bridge 

 over the creek, was found to be 392.77 feet above sea level V/i 



(2) Shale with thin layers of limestone and argillaceous sandstone. 

 The limestone yielded: Hallopora subnodosa, Rhinidictya cf. parallella, 

 Hallopora onealli creditensis, Strophomena planumbona erindalensis (abund- 

 ant), Strophomena varsensis, Rafinesquina alternata, Rafinesquina alternata 

 subcircularis, Hebertella occidentalis, Zygospira modesta, Ctenodonta cingu- 

 lata, Modiolopsis concentrica, Byssonychia sp.,. Isotelus sp 4'/2 



(1) Grey fissile to brown and black, rubbly shale with: Rafinesquina 

 alternata, Hebertella occidentalis, Strophomena varsensis, Byssonychia 

 radiata, Byssonychia cf. praecursa, Whiteavesia pholadiformis , Pterinea 

 demissa, Lophospira tropidophora, Lophospira bowdeni, Clathrospira cf. 

 subconica, Isotelus cf. maximus 4 



The rocks below and above the road bridge, one mile west of the mouth of 

 the creek, belong to Horizon No. 6 (Upper Erindale). The bryozoan reef 

 (Horizon No. 3) is seen about 100 yards east of the bridge. 



SECTION No. 9.— COOKSVILLE CREEK (394 to 447) 



Thickness 

 feet 



A full account of this section will not be given here, with the exception 

 of a few features which have a bearing on the Credit River section proper. 

 The Strophomena varsensis zone is well exposed and the bryozoan reef is 

 seen approximately in the middle of the zone, just as it is in Mullet creek. 

 By wye level, the elevation above sea-level of the under side of the reef in 

 this section is 459.95 feet. In Cooksville creek as well as in Mullet creek, 

 the zone is characterized by the abundance of Heterotrypa definita. 

 Stigmatella hybrida, a new species, was also found. Calloporella vacua, 

 another new species, was found about 10 feet below the reef 53 



SECTION No. 10.— WEST SIDE OF RIVER, NORTH OF HOME OF WILLIAM CROZIER 



(424 to 447) 

 Erindale Member: Thickness 



feet 



In descending order: — 



(3) The upper zone consists of shale with numerous layers of argil- 

 laceous sandstone varying in width from one inch to one foot. Limestone 

 layers are rare, but two or three one-half inch slabs which evidently came 

 from this horizon were found on the side of the cliff. They contain: 

 Homotrypella hospitalis, Hallopora onealli creditensis, Hallopora cf. onealli, 

 Whiteavesia pholadiformis , Byssonychia cf. radiata 18 



(2) The lower zone {Strophomena varsensis zone) consists of limestone 

 with very abundant examples of Strophomena varsensis-, also: Stropho- 

 mena planumbona erindalensis, Rafinesquina alternata subcircularis, 

 Trematis millepunctata, Heterotrypa definita, Hallopora onealli creditensis, 

 Rafinesquina alternata. The under side of this band was determined by 

 wye level to be 409.41 feet above sea-level 1 



(1) The lower four feet, extending to water-level, consists of fissile, 

 grey shale, with no fossils. By wye level, the creek bed at this locality 

 was determined to be 405.27 feet above sea-level 4 



