88 The Irish Naturalist. 



Britain from the Continent, which, we are told, " appears to be 

 evident from the circumstance that it is not mentioned as 

 occurring here previous to the fifteenth century, coupled with 

 the fact that its remains are unknown in English cavern 

 deposits," we very much doubt the application of this state- 

 ment to Ireland, since Rats are certainly mentioned in Irish 

 literature of much older date than the fifteenth century. 

 Those who are curious on this subject would do well to con- 

 sult Mr. David Comj^n's ''Irish Illustrations to Shakespeare " 

 (p. 2i), recently published at the Ficemafi's Ofiice, in Dublin, 

 where will be found much interesting information on this 

 matter, as well as on the ancient Irish custom of rhyming 

 Rats to death. ' The whole subject takes up more space than 

 is at our disposal if gone into thoroughly, and we must con- 

 tent ourselves with merely mentioning that Rats are alluded to 

 by Giraldus Cambrensis' as having existed in Ireland in the 

 6th century.^ Other allusions in Irish literature seem to show 

 the existence of the common House-mouse in Ireland in very 

 early times, and the date of its introduction, if it was 

 introduced, is certainly shrouded in mystery. 



The Rat described by William Thompson in 1837 as Mus 

 hibernicus is rightly placed by Mr. Lydekker under Mus 

 decumanus as a variety of that species. Since the paper'*, 

 in which that conclusion was finally come to, was written, we 

 have been able to amass a great deal of additional information, 

 all of which strengthens the position there taken up. 

 Specimens have been examined which were intermediate in 

 coloration between Mus hibernicus and Mus deciwiajiuSy and 

 an interesting family of rats which was brought to our notice 

 through the kindness of Mr. D. R. Pack Beresford, of 

 Bagnalstown, Co. Carlow, consisted of an old female Mus 

 decumanus and ten young ones, eight of which were Mus 

 decumanus and two Mus hibernicus (one of the latter having the 

 typical white breast-spot). In addition to the specimens 

 alluded to in the above paper, we have now examined 

 specimens from the following additional Irish counties, viz. : 



^ Vide, " As you Like it." Act iii., Sc, 2. 

 '^ Top. D. Z., c. 6, and in other places. 



8 Vide also "The Proceedings of the Great Institute," published in 

 i860 by the Ossianic Society. 

 * Zoologist^ 1891, p. I. 



