16 
MURIDJE/ 
Many years ago, I noted that numerous specimens, sent to me from 
stack-yards in the North of Ireland, were larger, lighter in colour, and 
more handsome than those found in houses. The Rev. L. Jenyns has 
since published the following remark in his “ Observations in Natural 
History ” (1846), p. 74 : — 
“ The colours of the common mouse are naturally extremely bright, and can 
hardly be judged of from individuals found in houses, which contract more or 
less of a dingy hue from the dirt of buildings and the nature of the recesses 
they frequent. To see these colours in perfection, we should have recourse to 
mice found in stacks, which are often so remarkable for their bright yellow tinge, 
that I once thought they might prove to be of a distinct species. This is due 
to an annulus of yellow surrounding each hair on the upper parts, a little below 
the extreme tip, which in the domestic mouse is rarely noticeable.” 
The Black Rat, Mus rattus, Linn. 
This rat, which once prevailed from North to South of the island, is now 
almost wholly extinct everywhere. It is not considered indigenous to 
Great Britain any more than the common brown rat, Mus decumanus 
(Bell’s Brit. Quad.). Both are believed to have been introduced to 
Europe from the East. 
I have received notes of the occurrence of black rats at Ballyheigne 
Castle (County Kerry) ; Youghal (County Cork) ; and Crowhill (County 
Armagh) ; but have no proof that they were of this species. Seven or 
eight of the latter were killed at Talaght, near Dublin, in February, 1834, 
one of which I saw in Mr. Warren’s collection. 
Colonel Portlock informed me, in 1840, that a specimen of the Mus 
rattus was sent to the Ordnance Museum, from Portglenone (Co. Antrim), 
by the late Archdeacon Alexander, who stated that they were tolerably 
abundant there. 
In December, 1842, Mr. Edward Benn, of Glenravel, forwarded to me 
one of these animals killed in his neighbourhood ; and Dr. Harvey, in 
the Fauna of Cork, p. 2, notes, regarding the species : — “ In old build- 
ings, in the northern parts of the city of Cork, near Garryclonne, &c., 
rare.” There is no doubt of these being the true Mus rattus , and not 
black varieties of M. decumanus , which are sometimes mistaken for it, as 
Dr. Harvey, in a letter to me, observed, that “they were much smaller, 
more delicate in the limbs, and altogether strikingly different from the 
brown rat.” 
Mus Hibernicus, Thompson. 
I made the following communication, on this species, to the Zoological 
Society of London, in 1837, in the proceedings for which year it was 
published : — 
“ Mus Hibernicus— (Irish. Rat). — On questioning a person, some years ago, 
respecting a black rat which he had seen in the North of Ireland, my curiosity 
was excited ,by the statement that it had a white breast. In autumn last, a 
similar description was given me of one that had been caught, some time before, 
in Tollymore Park (County of Down). Mr. R. Ball, of Dublin, informs me 
that black rats, with the breast white, have been reported to him as once com- 
mon about Youghal (County of Cork), though they are now very rare or perhaps 
extinct. But until April last, when a specimen was sent from Rathfriland 
(County of Down) to the Belfast Museum, I had not an opportunity either of 
seeing or examining the animal. This individual differs from the M. rattus, as 
described by authors, and also from specimens preserved in the British Museum, 
