W. Williams— The Megaceroa in Ireland. 355 



Preparator, I was desirous to obtain specimens to set up for sale. 

 But I was further desirous to know something of the circumstances 

 under which these remains were found. As a commercial speculation 

 my work was successful. Of the result of my scientific observations 

 and conclusions others must judge. In the years 1876-77 I spent 

 ten weeks excavating Deer-remains in the bog of Ballybetagh ; 

 subsequently I have made similar excavations in the counties of 

 Mayo, Limerick, and Meath; so that I am not without some ex- 

 perience in this matter. 



It may be premised that these peat-bogs occupy the basins of 

 lakes, the deeper hollows of which have long since been silted up 

 with marls, clays, and sands, and on this silt or mud the plants 

 which produced the peat grew. I find a general resemblance in the 

 order of succession of the beds in all the bogs I have examined ; 

 variations in the infilling materials and other circumstances will 

 account for any local diversity that may exist when comparing one 

 locality with another. 



The examination of these deposits is of interest not only on 

 account of the remains of these fine animals which they yield, but 

 also because I believe these beds afford the most reliable record we 

 have of the changes of climate that have occurred, not in this country 

 alone, but also over the whole northern hemisphere, from the close 

 of the great Glacial Epoch to the time of the covering up of these 

 silted-up lakes by the growth and accumulation of peat. 



In treating the subject we shall describe the Bog of Ballybetagh, 

 and take it as a type of the bogs throughout the whole country. I 

 select Ballybetagh, because it was there I arrived at the conclusions 

 here advanced ; and having spent ten weeks in making excavations, 

 I have an accurate knowledge af it. It was moreover the scene of 

 one of the excursions made by the British Association in 1878. 

 Prof. W. Boyd Dawkins refers to the visit in his new book, " Early 

 Man in Britain ; or Man's Place in the Tertiary Period." 



Ballybetagh Bog is situated in a small valley, lying between some 

 outlying hills south-east of the Three Eock Mountains, about nine 

 miles south-east of Dublin, at an elevation of about 800 feet above 

 the sea-level, and is bounded east and west by low granite hills, the 

 valley itself running north and south, where it is intersected by the 

 Glencullen river. Two small lakes occupy the bottom of this valley, 

 forming something like the figure oo . The larger loop occupies the 

 northern end, the smaller one lying towai'ds the south, at a higher 

 level, but connected with the northern lake, and receiving its over- 

 flow, which it discharges into the Grlencullen river. The Megaceros 

 remains have been found mostly in the smaller lake. Both of the 

 lakes have been silted up, and are now pasture-land. 



Having described the locality, one point is worthy of notice : its 

 elevation prevented it from receiving the drainage of any long sweep 

 of country ; hence there could not have been a rush of water through 

 it, and the clays could not have been imported into it from a 

 distance ; consequently they must liave been brought down from the 

 hills that immediately surround the valley, and, as their surface 



