130 Geological 'Gleanings. 



too ready to grasp at any semblance of fact, that tends to support 

 that strange doctrine of the diverse origin of the individuals of the 

 same species, with which in a manner so unworthy of his acute 

 mind, he endeavors to cut the knot of the difficulties in the geo- 

 graphical distribution of animals and plants, the legitimate solu- 

 tion of which forms one of the most interesting problems of geo- 

 logy and its allied sciences. 



The following is a list of species collected by Prof. Holmes, 

 which is sufficiently interesting, independently of those which may 

 be the debris of modern beef and mutton : — 



Extinct Species. — Mastodon, Megatherium, Megalonyx, Glypto- 

 don, Mylodon and- Hipparion, 2 species. 



Not now found on the Atlantic Coast, but indigenous to North 

 America. — Bison, Tapir, Peccary, Beaver, Musk-rat, and Elk. 



The Deer, Racoon, Opossum, Rabbit and the following Domestic 

 Animals — Horse, Hog, Sheep, Dog and Ox are not distinguishable 

 from the living species. 



Devonian and Carboniferous Rocks of Ireland. — The progress 

 of Geology is continually sweeping into one, groups of rocks here- 

 tofore distinct, and it is becoming a most exciting question where 

 will the breaks in geological time be ultimately left, or will there 

 be any breaks. Our geological chronology is like that of the old 

 Assyrian empire, where a few detached kings stand out on the 

 page of history broadly separated by intervals of time ; but just 

 as new monuments are disinterred, new names fill up the gaps, 

 and it is only as the list approaches completion that we can know 

 how and where one dynasty rudely or quietly displaced another. 



In Ireland a group of yellow and red sandstones, intervening 

 between the carboniferous and silurian systems, have been vari- 

 ously referred to the former, and to the Devonian period. Some 

 of the Irish Geologists even appear desirous of including the 

 whole, and with them the greater part of the Old Red of Scot- 

 land, among the carboniferous rocks. The case is thus stated by 

 Mr. Griffiths :— 



"No difficulty hence arises in regard to the position of the Old 

 Red series in the south of Ireland, it having been clearly ascer- 

 tained to conform to the Carboniferous strata above, while resting 

 unconformably upon the Silurian series beneath. The only ques- 

 tion that will arise regarding it is, as to what system it will of right 

 belong. And here I must enter upon an explanation of the principle 

 of subdivision by which I have been hitherto influenced. Finding, 



