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Show 1900.] MUS SYLVATICUS AND ITS ALLIES. 407 Mouse-prove to be different from the present form and identical with Mice from Scandinavia, it is unfortuuately necessary that Mus fiavicollis 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. Tbe use of the name fiavicollis by other writers, such as Dehne, was probably in connection partly with 31. 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 sglvaticus, 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 m m. 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 vertebras as 30, as against 27 only in the latter subspecies. From 31. 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 m m . and upwards. Distribution. Sporadically distributed in colonies amongst 31. s. intermedins in England, but replacing it eastwards. From England I have seen specimens from Graftonbury (de Winton) and Bishopstone, Herefordshire ; Oundle, Northants (the late Lord Lilford); Sussex, Suffolk, and Northumberland. On the Continent it seems to become more dominant towards tbe east, until it must somewhere intergrade with its eastern representative, M. s. princeps, which appears to be the only form in Boumania, and perhaps also in S. Bussia. Towards Denmark and in the neighbourhood of the South Baltic it is replaced by M. s. typicus, JM. s. cellarius, 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 Pirna in Saxon Switzerland, while Prof. Nehring1 states that there are specimens in the 1 Katalog der Saugethiere, p. 13 (1886). 27* |