Sciiarff, Seymour, and Nbwton — Castlcpook Cave. 55 



Lemmings. 



As we pointed out in the preliminary report, 1 the bones and teeth of the 

 Arctic and Scandinavian Lemmings occurred in great abundance in this cave. 



Both in the caves of Kesh and Co. Clare only one kind of Lemming had 

 been noticed. In the Cork cave a second form (Lemmus lemmus), a species 

 still living in Scandinavia, was discovered and identified by me. In order to 

 make certain of the correctness of the identification, I sent all the Irish 

 Lemming remains to Mr. H. A. C. Hinton, who was then engaged in the 

 classification of the fossil rodents in the British Museum. Mr. Hinton kindly 

 confirmed my identification of the Scandinavian Lemming. 



As regards the Arctic Lemming, he points out that the maxillary molar is 

 more reduced in the specimens from Castlepook Cave than in Dicrostonyx 

 torquatus, approaching the Arctic American Dicrostonyx hudsonius in that 

 respect. As there are some points of -difference from the latter in the skull, 

 Mr. Hinton considers the Irish Arctic Lemming sufficiently distinct from the 

 two recent species to rank as a new species, which he calls Dicrostonyx 

 henseli. 2 No specific character discriminating the Lemming's bones from one 

 another has yet been noticed. In the great majority of cases it is impossible, 

 therefore, to determine the species of the Lemming remains. More than a 

 thousand Lemming bones were collected in Castlepook Cave, most of them 

 being associated with the bones of Beindeer and Bear. Out of thirty 

 parcels containing Lemming teeth, seven were referable to Lemmus lemmus 

 and four to Dicrostonyx henseli. 



Scandinavian Lemming (Lemmus lemmus . 



This is the first time that the still existing Scandinavian Lemming has 

 been identified in Ireland. It had been known as a fossil from the south of 

 England and the continent of Europe. 



Arctic Lemming (Dicrostonyx henseli). 



In the paper just quoted 2 Mr. Hinton gives a description of Dicrostonyx 

 henseli, and informs us how it is to be distinguished from the still existing 

 Arctic Lemming (D. torquatus). According to Mr. Hinton, the records of 

 Dicrostonyx torquatus from the Kesh and Clare caves are not quite correct. 

 The name of Dicrostonyx henseli should be substituted, except in a few 



1 Ussher, R. J., H. J. Seymour, E. T. Newton, and R. F. Scharfl": " On the Cave of 

 Castlepook, near Doneraile, Co. Cork." Brit. Assoc. Report. Dublin, 1!K)8. 



2 Hinton, H. A. C. : "Some new Late Pleistocene Voles and Lemmings," Annals 

 and Mag. Nat. Hist. (8), vol. vi. 1910. 



