1862.] DA>yS0N DEYOXIAN PLANTS. 303 



2. Reddish conglomerate, with quartz pebbles ; reddish, pur- Feet. 



pie, and grey sandstones and grits ; deep-red, grey, and 

 pale-green shales. A few fossil plants 2350 



3. Blackish and grey hard shale and arenaceous shale ; buff 



and grey sandstone and flags. Many fossil Plants; 

 Crustaceans and Spirorbis 2000 



4. Reddish conglomerate, with slaty paste and rounded pebbles; 



trappean or tufaceous rock; red, purplish, and green 

 sandstones and shales. Thickness variable 1000 



5. Black papyraceous shale, with layers of cone-in-cone con- 



cretions 400 



6. Hard, generally coarse and micaceous, grey shales and flags, 



of various shades of colour, and with some reddish shale 

 and tufaceous or trappean matter at the bottom. Lin- 

 ffulce, Burrows, and Trails of animals 3000 feet or more. 



7. White and grey crystalline limestone, with bands of shale 



and beds of graphite 600 feet or more. 



8. Gneissose and other metamorphic beds, mth bands of quartz- 



rock and slate. Thickness unknown. 



The Devonian age of the upper members of this great series of 

 beds I regard as established by their fossils*, taken in connexion 

 with the unconformable superposition of the Lower Carboniferous 

 conglomerate. The age of the lower members is less certain. They 

 may either represent the Middle and Lower Devonian, or may be in 

 part of Silurian age. Their only determinable fossil, the Lingula of 

 the St. John shales, affords no decisive solution of this question, and 

 the evidence of mineral character is not to be relied on in the case of 

 beds so remote from tbose regions in which the Devonian rocks of 

 America have been most minutely studied. 



In mineral character, Nos. 1 & 2 of the above sectional Kst might 

 very well represent the Old Red Sandstone, or Catskill gToup of the 

 New York geologists. Nos. 3 & 4 might be regarded as the ana- 

 logues of the Chemung and Portage groups. ISTo. 5 would represent 

 the Genesee Slate ; j^o. 6 the remainder of the Hamilton group ; 

 No. 7 the Corniferous Limestone ; and !N o. 8 might be regarded as a 

 metamorphosed equivalent of the Oriskany and Schoharie Sandstones. 

 The entire want of the rich marine fauna of these formations is, 

 however, a serious objection to this parallelism. If, on the other 

 hand, we employ as our scale of comparison the development of the 

 Devonian system in Gaspe, Nos. 1 & 2 will correspond very well 

 with the upper member of the Gaspe series, and No. 3 with the rich 

 plant-bearing beds of the middle of that series; but no mineral 



* The scanty animal remains of the plant-beds No. 3 accord very well with 

 the evidence of the fossil Plants. They are a small Trilobite, apparently a Phil- 

 lipsia, three other Crustaceans, one of which is probably a Sti/hnurus, another a 

 Kuryfterva, and the third a Decapod not apparently referable to any described 

 genus. These Crustaceans are now in the hands of Mr. Salter. (See his paper 

 on these fossils, read before the Society, May 21, 1862.) There is also a shell, 

 apparently a Loxonema, and a Spirorhh. 



