34 Dentition and Characters 



Millim. Inc. Lin. 



Length of body, .... 0,070 = 2 9i 



of tail, .... 0,045 = 1 9£ nearly. 



From the orifice of the ear to the end of 



the snout, .... 0,021 = 10, or more. 



From the eye to the same point, . 0,010 =0 4| j 



which are not very different from those of many individuals of our 

 common species, which last varies very much in this respect,— in 

 the relative length of the tail and body especially. 



The S. tetragonurns was first described by Hermann, in 1783, 

 from specimens found in the neighbourhood of Strasburg by the ce- 

 lebrated Dr Gall. To his work, entitled Tabula affinitatum Ani- 

 malium, I have had no access. The species, however, has been sub- 

 sequently noticed by several other authors besides Duvernoy, in 

 whose descriptions I find scarcely any thing at variance with the 

 characters of the S. araneus of this country. Geoffroy 's, , indeed, is 

 almost the only one which appears founded upon original observa- 

 tion.* And one remark of his, relating to the teeth, which perhaps 

 may be thought not strictly applicable to our species, it will be right 

 to notice. He states that all the canines, (by which name he de- 

 signates what in this paper are called lateral incisors) are of equal 

 size. But it must be remembered, that he is here, as well as in 

 most other parts of his description, contrasting the S. tetragonurus 

 with the S. araneus of the continent, in Avhich last, according to 

 Duvernoy, the teeth in question diminish in size very rapidly. 

 Hence the expression must not be taken strictly, and according to 

 the letter. As to the form of the tail, which has obtained for it 

 its name, and which is much dwelt upon by Geoffroy, we have al- 

 ready shown that this is not in any case to be depended on. The 

 dimensions given by him are : 



Length of body 60 millimetres = 2 inc. 4^ lin. nearly, 

 tail 40 =1 inc. 7 lin. 



which differ from those of Duvernoy, shewing that in this respect 

 the S, tetragonurus is equally variable as our British araneus. Its 

 tendency to vary in other respects also, we may gather from the ac- 

 count of this species by Isidore Geoffroy St Hilaire in the Diction- 

 naire Classique d'Histoire Naturelle,\ where, after repeating several 

 of the characters already noticed by Geoffroy, he states that he has 

 examined many individuals apparently referrible to it, in which he 



* Memoire sur les especes de genre Musaraigne — Ann. du Mus. Tom. xvii. 

 (1811,) p. 177, pi. 2, f. 3. 

 f Tom. xi. p. 320. 



