1900.] MUS STLVATICUS AND ITS ALLIES. 407 



Mouse — prove to be different from the present form and identical 

 with Mice from Scandinavia, it is unfortunately necessary that 

 Mus Jlavicollis Melchior should stand as a synonym of 31us 

 sylvaticus typicus Linn. Mr. de Winton's discovery, therefore, 

 needs a new name, and I now take the opportunity of connecting 

 it with its discoverer, to whose excellent field-work amongst 

 British Mammals we owe our knowledge not only of this, but of 

 the Hebridean subspecies. The use of the name jlavicollis by other 

 writers, such as Dehne, was probably in connection partly with 

 M. s. typicus and partly with M. s. princeps, so that a certain 

 amount of nomenclatural confusion cannot well be avoided. 



Distinguishing Characteristics. Generally speaking, a remarkably 

 finely developed Mus sylvaticus, in which the size is above the 

 average, and the colours both of the upper and under sides are 

 very pure and intense. Specimens of all ages usually, but by no 

 means always, possess a well-defined breast-band, "about 8 mm. 

 broad, passing along the chest, immediately in front of the fore 

 legs, with a cross or longitudinal stripe in the centre extending 

 forward about 5 mm., and back along the sternum about 10 mm., 

 where it is entirely lost, unlike the slight dash of colour so frequently 

 found on the chest of Mus sylvaticus, and which varies from the 

 smallest spot on the breast to a decided yellow-brown tinge 

 extending over the whole belly " (de Winton, op. cit.). The tail 

 is longer than in M. s. intermedins; and Mr. de Winton gives the 

 number of vertebra? as 30, as against 27 only in the latter sub- 

 species. From M. s. princeps it may, perhaps, best be distinguished 

 by its slightly duller colour and the more frequent occurrence and 

 greater extent of the breast-band. Western specimens show the 

 greatest development of the breast-band, which seems to become 

 less conspicuous towards the east. 



Skull larger and stronger than in M. s. intermedins, reaching a 

 total length of 27 mm. and upwards. 



Distribution. Sporadically distributed in colonies amongst M. s. 

 intermedins in England, but replacing it eastwards. From 

 England I have seen specimens from Graft on bury (de Winton) 

 and Bishopstone, Herefordshire ; Oundle, jYortbants (the late 

 Lord Lilford) ; Sussex, Suffolk, and Northumberland. On the 

 Continent it seems to become more dominant towards the east, 

 until it must somewhere intergrade with its eastern representative, 

 W . a. princeps, which appears to be the only form in Roumania, 

 and perhaps also in S. Russia. Towards Denmark and in the 

 neighbourhood of the South Baltic it is replaced by M. s. typicus, 

 M. s. cellariits, or by intermediate forms, a set of which I have 

 myself trapped at Brunswick. There are in the British Museum 

 specimens from Tharand, Saxony; Magdeburg; Haida, Bohemia; 

 Niesky, Silesia, and from Western Hungary. So long ago as 1855 

 A. Dehne (op. cit.) recognized a big Field-mouse with golden collar 

 and long tail as not rare in the district of Pima in Saxon Switzer- 

 land, while Prof. Nehring 1 states that there are specimens in the 

 1 Katalog der Ssiugetliiere, p. 13 (1886). 



27* 



