6 THE ZOOLOGIST. 



who sent us specimens from the Saltee Islands, off the Wexford 

 coast, remarks that they live there with the Brown Rats, and do 

 not appear to interfere with each other. 



Perhaps the most interesting, as well as the most singular, 

 feature in the history of Mus hibernicus is its peculiar and limited 

 geographical distribution. It is not rare, and is very widely 

 distributed in Ireland. Out of that country, the only known 

 localities for Britain in which it occurs are in the Outer 

 Hebrides, where it has long been known to the inhabitants, and 

 whence we have examined three specimens. It would appear to 

 be quite unknown on the mainland of Britain, where all our 

 endeavours to procure specimens have failed, though we should 

 certainly not be surprised to find that a melanism of so common 

 a creature as the Brown Rat should now and then occur. It 

 seems certain, however, that such varieties are very far from 

 common. On the Continent of Europe the only instance of the 

 occurrence of black varieties of Mus decumanus known to us is 

 the one recorded by A. Milne-Ed wards(Ann. Sci. Nat. 1871, xv. 

 art. 7) for Paris, where, in 1871, it had been known for twenty 

 years in the Menagerie of the Museum, and is described as 

 abundant and increasing in numbers. 



The somewhat common and general occurrence of this 

 melanic form in the circumscribed areas indicated should, it is 

 thought, afford some help towards the solution of the interesting, 

 but as yet unexplained, phenomenon of melanism. In this con- 

 nection, it may not be considered out of place to allude to 

 another melanic form, Sabine's Snipe, which has occurred in 

 Ireland, we believe, much more frequently than elsewhere ; thus 

 out of about thirty recorded examples, one appears as a con- 

 tinental specimen, one is from Scotland, about ten from England, 

 while no less than about eighteen are credited to Ireland. 



Considerable trouble has been taken to investigate the 

 distribution of Mus hibernicus in Ireland, and communications 

 have been received on the subject from almost every county. 

 Further investigation is, however, still needed. This we hope 

 to undertake, and, should it prove successful, it may form the 

 subject of a future communication. Though a careful record has 

 been kept of all the localities from which positive evidence of the 

 existence of these Black Rats has been received, it has been thought 



