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May 22, 1832. 

 Richard Owen, Esq., in the Chair. 



Mr. Yarrell exhibited skeletons and stuffed specimens of several 

 Mammalia, in illustration of the distinctive characters of two species 

 of that class, which he had recently ascertained to be inhabitants of 

 Britain. 



The first of these additions to the British Fauna is the oared Shrew, 

 Sorex remifer, Geoff., distinguishable from the more common water 

 Shretv by its greater size and its uniform colour. The whole of the 

 upper part of the head, the body, and sides, are velvet black ; the 

 situation of the ear is marked by a tuft of white hairs, more con- 

 spicuous than in the water Shrew, from the greater contrast of co- 

 lour ; there is a small patch of light brown under the lower jaw ; the 

 under surface of the body is rusty black j and the tail is black, with 

 a line of pendent greyish white hairs along its under surface. 



Mr. Yarrell remarked, that although the individual exhibited (the 

 only indigenous specimen which he had yet seen,) was smaller than 

 that described by M. Desmarest in his 'Mammalogie' (the length of 

 the head and body being 3 inches 4 lines, and that of the tail 1 inch 

 9 lines), he had determined its identity with the species to which he 

 referred it, by comparison with a specimen of Sor. remifer, trans- 

 mitted by M. Baillon of Abbeville to the British Museum; the two 

 specimens being perfectly similar in every particular of colour, mark- 

 ings, and measurement. He further observed, that the Sor. ciliata 

 of Sowerby's * British Miscellany,' pi. 49, is probably referable to 

 the same species. 



The second animal to which Mr. Yarrell more particularly directed 

 the attention of the Committee, was a species of Arvicola, new, not 

 only to Britain, but also apparently to science. It is so nearly re- 

 lated to Arv. agrestis (the Mus agrestis of Ray, and probably also 

 of Linnaeus, and apparently the Mus arvalis of Pallas), as to require 

 that the characters of the latter, the common short-tailed jfoW Cam- 

 pagnol, should be modified. Mr. Yarrell accordingly thus charac- 

 terized the two species : — 



Arvicola agrestis. Arv. supra rufescenti-Jusca, subtiis cinerea i; 

 auriculis vix prominulis ; Cauda tertiam partem corporis longitu- 

 dine vix cequante. 



Arvicola riparia. Arv. supra saturate castaneo-rufescens, sub- 

 tits cinerea ; auriculis paullb prominulis ; cauda dimidium cor- 

 poris longitudine cequante, apicis pilis subelongatis. 

 Mr. Yarrell pointed out, on the specimens exhibited by him, the 

 external differences between these species, consisting chiefly in the 

 size and colour of the body, and the relative length of the tail. He 

 [No. XIX.] Zool. Soc. Proceedings of the Comm. of Science. 



