No. 5.] 



DONALD — HELDEBBERG ROCKS. 



303 



grounds of their lithological character only, since they are " a 

 dolomitic conglomerate so similar to that of St. Helen's Island, 

 with the exception of the associated masses of limestone, that 

 they are most probably of the same age." * 



As to the fossils of this deposit, but little seems to have been 

 done. Report of Geological Survey of Canada for the year 1863 

 says : " The fossils observed in this limestone are Favosites Goth, 

 landica, Strophomena rhomboidalis, S. punctuli/era. Orthis 

 ohlata, an undetermined species o^ Rhynchonella with R. Wilsoni, 

 Athyris hella, Atrypa reticularis and two undetermined species 

 of Spirifera. 



The students attending the class in Geology in McGill College 

 visit various places in the neighborhood for the purpose of study- 

 ing practical Geology and collecting fossils. Among other places, 

 St. Helen's Island is frequently visited, and, as a result, quite 

 a collection of fossils from this deposit accumulated in the Col- 

 lege. Having access to this collection, and possessing a small 

 one of my own, I endeavored to determine the fossils thus 

 obtained, the result being embodied in the following list, which 

 comprises sixteen genera and thirty six species : 



Crinoid (stems), 

 Favosites Gothlandica, 

 Favosites, 

 Stenopora, 

 Fenestella, 

 Ptilodictya acuta, 

 Orthis hipparionyx, 



" discus, 



" oblata, 



" tubiilostriata, 



" eminens, 



" deformis ? 



Orthis 



Strophomena punctulifera, 

 " profunda, 



« rhomboidalis, 



Strophodonta varistriata, 



" radiata, 



Spirifer concinnus, 

 " cyclopterus, 

 « allied to S. arenosus. 



Rhynchonella formosa, 



" Eequivalvis, 



" mutabilis, 



" allied to R. 



miutabilis, 

 " nucleolata, 



" ventricosa, 



" Species undeter. and not 

 described in Hall. 

 Atrypa reticularis, 

 Stricklandinia Gaspensis, 

 Pentamerus Verneuili, 

 " galeatus, 

 " pseudo-galeatus, 

 Avicula, perhaps allied to 



A. manticula, Hall. 

 Platyostoma depressa, 

 Tentaculites Helena (new 

 species.) 



Report Geological Survey of Canada, 1863, p. 356. 



