W. Williams — The Megaceros in Ireland. 863 



As far as I have seen, the reclothing of the country by forest after 

 the denudation of the " Ice age," made little progress till near or 

 after the times of the peat. In the lower deposits of the lake-beds I 

 never found any timber nor met with the Megaceros remains. In the 

 glacial beds just under the peat, I have found some branches ; but in 

 the peat, as is well known, trees are of common occurrence ; nor is 

 it surprising that prairie should precede forest growth by a very long 

 period.^ 



Thus, having traced the silting up of an Irish lake, and the 

 probable changes of climate that an examination of the clays con- 

 tained therein indicate, we find : — 



1st. A cold wet climate, as marked by clay No. 1, which was 

 evidently washed from the hills in the great thaw ; it is a pure rain- 

 wash or glacial fluviatile clay. 



2nd. A dry and warm period, which succeeded the former, marked 

 by the accumulation of the bed of vegetable matter found in the 

 very bottom of these lakes, during the growth of which the land 

 probably became covered with prairie. 



3rd. A mild and genial climate, during which the Megaceros ap- 

 peared in Ireland, leaving the bones of drowned individuals in the 

 lakes, where we find them surrounded and covered up by the brown 

 clay No. 3. The drowning appears to have been caused by the animals 

 having mired or stuck fast in the thick tenacious clay No. 1. 



4th. Another glacial period, indicated by the greyish clay described 

 as No. 4, ice-action or frost and thaw bringing it down from the hills, 

 thus filling the lakes, afterwards by the lowering of their level and 

 making the surface of the clays fit for the peat plants to root in. 

 The cold of this period having probably exterminated the Megaceros 

 in Ireland. 



I believe it will be found that these clays are a key to the changes 

 of climate that have occurred in the northern hemisphere from the 

 great Glacial period up to the times of the peat and forest growths. 



2, Dame Street, Dublin. 



1 In a letter to the writer from Dr. James Geikie, F.E.S., F.G.S., of the 

 Geological Survey of Scotland (author of a work entitled "The Great Ice Age," 

 etc., one of our highest authorities on glacial questions), this eminent geologist 

 writes as follows :■ — ■" Perth, 1st January, 1880, .... As I told you in former 

 letters, I was not prepared to believe that your marls and peat with Megaceros 

 could be older than the last cold phase of the Ice-age. I thought then, and think 

 still, that they are all Post- Glacial — in the sense of being later than the last big 

 ice-sheet. But I think you are right in supposing that cold conditions of climate 

 succeeded to the period when the Megaceros lived in Ireland." . . . . " You will 

 see from my paper that your Megaceros comes into the ' Age of Forests,' and that 

 the beds immediately overlying the peat will most likely be of the same age as our 

 coarse clays, with Greenland whale, and the latest local, or valley-glaciers — a climate 

 probably approaching to that of Northern Norway." 



The writer believes the Megaceros lived before the forest-period in Ireland, just 

 as it existed previous to the growth of the Peat-bogs. 



