192 The Ottawa Naturalist. [Feb. 



The strata immediately overlying the clavigera zone were 

 well exposed in the trenches at Rockcliffe, especially on Buena 

 Vista Road in front of the residence of Mr. Elfric Drew Ingall of 

 the Geological Survey, who made a large collection of the fossils. 

 A large species of Loxoceras, and Modiolopsis parviuscula were 

 common in the sandstones, and a few thin beds of limestone 

 associated with them were full of Leperditia canadensis nana. A 

 bryozoan, which Dr. Bassler has identified as a Dekayella similar 

 to D. simplex, Ulrich, was abundant in the sandstone. 



Within 20 feet above the clavigera zone at Aylmer there are a 

 number of thin layers of limestone almost entirely made up of 

 ostracods, and with the ostracods are found Helicotoma ivhite- 

 avsiana, Bathyums angelini, and a Cry'todonta. 



The strata above those exposed at the station on the electric 

 railwav are well exposed at the Hogs Back: 



Ft. In. Ft. In. 



8. Blue-gray limestone mostly rather heavy- 

 bedded. Some layers very fossiliferous 10 6 10 6 



7. Rather pure dark gray limestone with 



irregular wavy bedding 5 15 6 



6. Heavy-bedded, fine grained light gray to 

 cream-colored sandstone with Vanux- 

 emia and other lamellibranchs 4 6 20 



5. Dark gray shale, with two or three thin 



layers of limestone 1 8 21 8 



4. Heavy-bedded sandstone with many 



replaced bryozoa 3 9 25 5 



3. Shale and thin-bedded black limestone 



with ostracods 4 9 30 2 



2. Thin-bedded sandstone and shale 5 9 35 11 



1. Heavy -bedded, greenish limestone 8 6 44 5 



No. 1 of this section is believed to be the same as No. 12 of 

 the section at Westboro. 



The sandstone. No. 6 of this section, is a very important one, 

 as from it Mr. W. R. BilHngs obtained the various species of 

 lamellibranchs described by the late Dr. Whit eaves in vol. XXII, 

 No. 6, of The Ottawa Naturalist. This same layer, with the 

 same fossils, was found on the road leading down to the river 

 just beyond the Robillard quarries on Montreal Road, about 53 

 miles east of Ottawa. The section there is as follows: 



Ft. In. Ft. In. 

 12. Massive, impure, dark gray lumpy lime- 

 stone with Cohimnaria halli and Ormo- 

 ceras tenuiflum near the base. Top 

 not seen. Black River 6 6 



