100 THE ROYAL SOCIETY OF CANADA 



Another condition which has added value to the plants found at 

 Kiltorcan is that they are contained in measures which preceded in 

 regular order, and without any geological break, the Lower-Carboni- 

 ferous limestone with marine organisms, whose age is unmistakeable; 

 and hence the plants in these shales and sandstones are undoubtedly 

 of Devonian age. In these measures the beds containing fossil plants 

 are about ninety feet below the Lower Carboniferous limestone, with 

 characteristic marine organisms. 



Among the geologists who have been to Kiltorcan and studied 

 its plant remains, three names stand out with prominence as students 

 of its Devonian vegetation, viz., Edward Forbes, Samuel Haughton and 

 Thomas Johnson, whose services to science in this connection are in 

 the order we have named ; for the last named is the one who has made 

 the most varied observations on these plants. In the case of Mr. 

 Forbes the examination was made in connection with his position as 

 palœontoligist of the Geological Survey, but in the case of the two 

 others the work was done in connection with their duties in the Royal 

 College of Science of Ireland. Of late years Professor Johnson has 

 devoted himself enthusiastically to the study of these plants, and has 

 kept a close watch on the quarrying operations in the sandstones where 

 the plants are found. He has thus developed a flora which is emin- 

 ently Upper Devonian and in Europe highly characteristic of that 

 period. His study has given to science from these beds a flora 

 which compares favourably with that of Oswald Heer and 

 A. G. Nathorst from Bear Island in the Arctic Sea, and is particularly 

 illuminating as a precursor to the better known floras that succeeded— 

 the Lower Carboniferous flora, and that of the Coal Measures. 



In the following account it seems best to take up the genera of 

 Kiltorcan in the order in which they have been described, mentioning 

 first the widely distributed genus Archa?opteris. 



Arch^opteris Hibernica: E. Forbes. 



Cyclopteris hibernica, Ed. Forbes. 

 Palaeopteris hibernica, Schimper (fide Crepin). 

 Archaeopteris hibernica, Johnson. 



Professor Johnson has devoted much study to this species and 

 in his memoirs in the Transact. Roy. Coll. Sci. Ir'd, gives a full and well 

 balanced account of its features, and especially those which bear 

 on its possible inclusion in the new Order of Pteridosperms, rather 

 than in that of Filicales, where for so long it has found a resting-place. 

 He considers its fern-like aspect, the dichotomy of its fronds and 

 pinna?, and remarks that its apheboid pinnœ are parallel to those of 



