Schauff, Seymour, and Nkwton — Castlepook Cave. 57 



outer ear becomes shorter. On the other hand, the eye has grown larger, 

 which lias had it due effect on the skull. This increased specialization was 

 not caused by the northern forms of hares having had to travel furthest 

 from the centre of dispersal. It is due to the fact that the northern members 

 of the variabilis group became exposed to abnormal or peculiar climatic 

 conditions As 1 have mentioned before, Mr. Ilinton urges, and I agree 

 with him, that when the Variable Hare inhabited the south of England the 

 climate of that part of the British Islands was temperate. But in the exist- 

 ing fauna and flora of Greenland there are many indications that the climate 

 of that part of the world was much less severe formerly than it is now. 1 It 

 is probable, then, that while the climate of the British Islands has fluctuated 

 comparatively little within recent geological times, that of Greenland has 

 altered considerably. Thus, although the Greenland form of the variabilis 

 group of hares is more specialized than those of the British Islands, it need 

 not necessarily be assumed that it lies on the periphery of the dispersal of 

 the group, nor that it is derived from a southern stock. 



Babbit {Orydolagus cuniculus = Lepus cunicultis). 



In my report on the animals of the Clare caves I suggested that the 

 Babbit was indigenous to Ireland. Some of the Clare bones of Babbit were 

 ancient- looking, and seemed to support this view. 



In the Castlepook Cave only two tibiae and one femur (M.D. 32 and 33) 

 show signs of antiquity. Almost all the other teeth and bones were quite 

 fresh-looking. None of them had been gnawed. The only two very old- 

 looking bones were femur fragments (M.D. 313), and these could doubtfully 

 be referred to this species. They may possibly belong to young hares. 



This is the first occasion on which a cave yielded the skull of a Babbit. 

 As a rule the bones are much broken. The skull alluded to is not perfect. 

 The anterior part is missing, and certain portions of the base are absent. 

 The only difference that could be observed between it and a recent Babbit 

 skull was that the orbits were slightly nearer one another in the fossil form. 



There is no reason to suppose that the Babbit was a native of the district 

 surrounding this cave at the time when the Hyaena and Mammoth lived in 

 the neighbourhood. This is all we can definitely assert after an examination 

 of the Babbit remains. 



Mammoth (Elephts prwiiycnius). 

 Mammoth bones were very abundant in the Castlepook Cave. Tney 



1 Scharff, R. F. : "Origin of Life in America," pp. 19-25. London, 1911. 



R.I. A. PROC, VOL. XXXIV, SECT. B. [77] 



