109 



numerous petrified trunks of the giant alga {Prototaxites) 

 (Nematophyton). One trunk, partially exposed, was 

 described as exceeding 3 feet (0-9 m.) in diameter. 



At one place, near the middle of the section, a coal bed 

 one inch to three inches in thickness, associated with 

 highly bituminous shales abounding in remains of plants, 

 and containing fragments of crustaceans and fishes, is said 

 to occur in the midst of grey sandstones and dark shale 

 which resemble ordinary coal measures. The coal, which 

 is shining and laminated, has no underclay, and appears to 

 consist of what was once a peaty mass of rhizomes of 

 Psilophyton, which now lies between layers of laminated 

 bituminous shale. This thin coal occurs near Tar point 

 on the south side of Gaspe bay, a place named for the oc- 

 currence of a thick dyke of trap holding petroleum in its 

 cavities. The coal is supposed to be of considerable 

 horizontal extent, the Tar Point outcrop being provision- 

 ally correlated with a similar bed about 4 miles (6-4 km.) 

 distant on Douglas river. 



The plants described by Dawson from Gaspe include 

 Prototaxites logani, Prototaxites {Nematoxylon) crassum, 

 P. ten-iie, Stigmaria areolata, S. minutissima (the latter 

 species being perhaps based on the rhizones of Psilophyton) 

 Didymophyllum reniforme, Catamites inomatus, Annularia 

 taxa, Lepidodendron gaspianum, Leptophleum rhombicum, 

 Lepidophloios antiquus, Psilophyton princeps, Psilophyton 

 robustius, P. elegans, Arthrostigma gracile, Cyclostigma, 

 Cordaites angustij olius and Parka related to, though smaller 

 than, the Scotch P. decipiens. 



The plants in the Gaspe section represent the Psilophyton- 

 Arthiostigma flora, which preceded the Archaeopteris flora 

 The genus Archaeopteris is present practically everywhere 

 in the floras of the Upper Devonian in Europe and America, 

 whereas the typical Psilophyton princeps, including the 

 spinous forms, together with Psilophyton robustius, 

 Psilophyton grandis and Arthrostigma, are characteristic 

 of a lower zone in both Canada and the eastern United 

 States. This older flora which is found in the Chapman 

 sandstone in Maine, seems hardly to have survived the 

 Hamilton group, above which (especially above the 

 Portage) the Archaeopteris flora reigns to the close of 

 Devonian time. 



