6 G. 8p. tiov. cc 



7 Coono^raptid yen. nor. vt sp. uoc. c 



8 Tetraj^raptus serra Brony. small iniit. c 



9 T. bigsl^vi Hall small mut. c 



10 T. fi'uticosiis Hall small mut. cc 



11 T. pendens Elks rr 



12 Didymograptns cf. similis Hall r 



13 D. bifidus Hall cc 



14 Phvllograptus typus Hall c 



15 P. anna Hall . cc 



16 P. angustifolius Hall c 



17 Xemagraptus sp. r 



18 Thamnograptus anna Hall c 



19 Lingula quebecensis B'iUukjs rr 



20 Small indet. brachiopods cc 

 To this zone belong also the beds j, k, 1, m and n, hard greenish 



silicious beds, sandy shales and limestones. Bed j bears, on 



black shaly partings, Didymograptns bifidus, the 

 most characteristic form of this zone. The thin graptolite bed 



4 in bed 1 also furnished this species and a few poorly preserved 

 fragments of some of the other forms. 



GniptoUtc bed 5 



Under this notation have been united the numerous shaly 

 partings between the heavy banks of greenish gray, extremely 

 hard, silicious rock which is exposed, with a thickness of 52 

 feet, in the quarry at the east end of the continuous section 

 (stratum o; the shaly partings are denoted on the diagram by 

 the letter p). Most of these partings are covered to the exclu- 

 sion of other species, with the rhabdosomes of the species 

 P h y 1 1 o g r a J) t u s t y p u s . P h. i 1 i c i f o 1 i u s (large muta- 

 tion) and Ph. anna. The largest specimens of Phyllo- 

 graptus typus occur however in a layer at the base of 

 graptolite bed .'?. The full list of the species observed in the 

 quarry is: 



1 Tetragraptus (iuadrilnadiiatus Hall c 



2 T. serra Bronq. r 



