10 PLEISTOCENE MAMMALIA. 



The most satisfactory explanation of the occurrence of such a mass of skeletons as 

 was found at Bally betagh is that offered by Williams (77). The lake in which the 

 skeletons occur occupied a hollow in the boulder clay with the sides sloping at an 

 angle of sometimes as much as 45°. The lake formed a natural trap which the animals 

 could easily enter, but from which escape was extremely difficult, partly owing to 

 the steepness of the sides, partly to the depth and tenacity of the clay forming the 

 floor of the lake. As the author points out, the large number found may be accounted 

 for on the supposition that one or two lost their lives in this fashion every season. 

 It is unnecessary to assume that the animals were destroyed as a herd. 



The suggestion by C. Reid (96) in the following paragraph also bears on this 

 question : 



" Those familiar with the pools containing Char a will be well aware of the appear- 

 ance of shallowness and of a solid floor, which is so deceptive. The Chara and Pota- 

 mogeton may grow from a depth of several feet, but they often appear to form a 

 carpet of bright green turf a few inches under the surface of the clear water. Any 

 animal treading on this turf would immediately plunge head foremost into the water, 

 and the wide-branching antlers of Cervus megaceros would become entangled amid the 

 Chara stems, and still tougher Pondweeds, so that the animal would have scarcely a 

 chance to escape." 



Porte says that the condition of the antlers — full-grown, but showing in the burr 

 and constriction round the base preparation for the fall — proves that the season of 

 the year at which the animals perished was the end of April (supposing the habits of 

 the Irish Giant Deer to be the same as those of Deer in Ireland at the present day). 



c. Cause of its Special Abundance in Ireland. 



The immense numbers of this magnificent Deer in Ireland and the fact that it 

 considerably exceeded its continental relatives in size, show clearty that the conditions 

 in Ireland must have been exceptionally favourable to it, both as regards climate 

 and in other respects. The scarcity of great Carnivora has always, as by Adams 

 (1881) and Ball (1885), been considered a chief cause of its abundance, the Lion and 

 Cave-bear not having been found in Ireland and the Hysena very rarely. Dr. Scharff 

 writes : ' They probably lived in an open prairie country and were comparatively 

 free from enemies. Hyaenas were not to be feared, for they probably became extinct 

 (in Ireland) sooner than the Giant Deer. The tremendous sweep of the heavy antlers 

 was a powerful defensive weapon against the Wolf, which was always abundant in 

 Ireland. It would seem that Man camped mostly near the sea among the hills, and 

 may only have arrived in Ireland when the Giant Deer was on the verge of extinction." 



Among the localities where the Giant Deer has occurred in special abundance are 

 the following : margin of Lough Derg, near Mountshannon, Galway ; Killowen 

 Wexford ; Ballybetagh Bog, near Kiltiernan, Dublin ; Ask Bog, N.E. of Gorey, 

 Wexford. 



