THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE V. VOL. VIII. 



No. XII.— DECEMBER. 1911. 



OEIGIMAL ARTICLES. 



I. — The British Eossil Shrews. 

 By Martin A. C. Hinton. 



(PLATE XXV.) 



REMAINS of Shrews have long been known to occur in the 

 Norfolk ' Forest Bed ', and have been discovered in several 

 British Pleistocene deposits. Hitherto they have been referred to 

 one or other of the three species at present inhabiting this country, 

 but having had occasion lately to examine nearly all the available 

 material, comprising representative series of specimens from each of 

 the known horizons, I find that it is not until we reach the latest 

 Pleistocene deposits that we meet with remains of species indistinguish- 

 able, with the material before us, from the living British forms. 



The Shrews are low Placentals specialized in two ways, viz., 

 (1) for an insectivorous diet, and (2) to a smaller degree for 

 a subterranean existence. They have been divided into two groups : 1 

 Soricincs, in which the teeth are more or less extensively stained with 

 a reddish-brown pigment ; Croctdurince, in which the teeth are quite 

 white. All the British species, fossil and recent, so far discovered 

 belong to the first group ; and so far as the characters of the fossil 

 forms are known they are all referable to one or other of the two 

 living British genera, Sorex and JSeomys. 



Sorex stands on a slightly lower plane than Neomys in most 

 respects. 2 It retains one more premolar above ; in the large lower 

 incisor three or four of the denticles primitively present upon the 

 crowns of mammalian incisors persist until an advanced stage of 

 wear has been reached 3 ; and the condyle of the lower jaw and 

 the glenoid articulation of the skull, although differing much from the 

 normal mammalian type, are a little less highly modified. In the small 

 size of most of the species, their external characters, and the form 

 of the skull and humerus, we see the effects of an adaptation to life 

 underground. 



1 Dobson, Proc. Zool. Soc, 1890, p. 49. Winge suggested this classification 

 many years before (Vidensk. Med. Nat. For en. Kjubenhavn, 1877, p. 138). 



2 The best account of the skull of the Shrews and of their relationships is to 

 be found in the following works of Winge : ' ' Om Muldvarpens og Spids- 

 musenes Cranier og Spidsmusenes systematiske Stilling," Vidensk. Med. Nat. 

 Foren. Kjobenhavn, 1877, p. 115 ; " Om Grseske Pattedyr," ibid., 1881 (1882), 

 p. 12 ; " Pattedyr," Danmarks Fauna, 1908, pp. 14-16, 22-7. 



3 Owen, Anatomy of Vertebrates, vol. iii, p. 306, 1868. 



DECADE V. — VOL. VIII. — NO. XII. 34 



