12 



first named formation, is represented by a continuous band of light grey 

 calcareous sandstone, holding in great abundance Orlhooer.ig Antenor, 

 ModiolojJsis parviuscida and several undescribed species of Ctenodonta. 

 This band has been traced a distance of about five miles, extendinof 

 from the second milestone on the Ayliner Road, in a westerly direction, 

 to where it outcrops on the Eardley Road opposite the residence of Mr. 

 F. Parker, In descending order, there occurs next to this a consider- 

 able thickness of shale, which immediately oveilies another heavy 

 dark colored bed of calcareous sandstone, which appears to be composed 

 for the most part of fucoidal remains, no other organic matter having 

 been found therein. These two strata, with their iatervening shales, 

 have been identified at about a dozen different exposures, and have been 

 found to preserve invariably the same stratigraphical order. Tt might 

 here be observed, that beds similar to these occur at Hog's Back, on the 

 Rideau River, with the exception that the upper beJ, at that place, 

 contains fewer and more poorly preserved fossils, and is a good deal 

 thicker than its equivalent at Aylmer. 



As a general rule the Aylmer shales have yielded very fair speci- 

 mens of characteristic Lingula, together with fragments of Isotelus canalis 

 and probably an undescribed species of the same genus ; but, where 

 they are deficient in well preserved specimens of the first mentioned 

 forms, they have been found, in many cases, to be crowded with the 

 comminuted remains of these delicate organisms. 



While the foregoing rem irks, relative to the finding at Aylmer of 

 typical chazy forms, are applicable in a great measure to the shales at 

 Hog's Back, an important exception was met with at the latter place 

 in the discovery of Lingula Mantelli, a membor of the Brachiopoda, 

 the upward range of which has hitherto been limited to thg Calciferous 

 formation. 



It might here be be obsarved that, in a paper read before the Club, 

 March 4th, 1885, Mr. H. M. Ami alludes to the occurrence, in one of 

 the fossiliferous beds at Hog's Back, of " numerous black phosphatic 

 nodules, probably coprolites," associated vrith Lingula Belli (Billings) 

 and Cyrtodonta hreviuscula (Billings). During the past season these 

 "nodules" have been examined and recognized as verv diminutive 



