268 Rev. L. Jenyns on some of 



, There are 6 lumbar vertebrae and 1 7 caudal, there being 1 

 more of these last than in any specimen of the S. tetragonurus 

 yet examined; and the entire number of vertebrae will stand 

 at 45 or 48, according as the sacral are reckoned at 2 or 5 as 

 before. This estimate was obtained from an examination of 

 three specimens. 



(8.) Soreoo ciliatus. — I have seen so many intermediate 

 specimens, in point of colour, between this and the last 

 species, that I consider it extremely doubtful whether they 

 be distinct. Nevertheless, it deserves to be mentioned, that 

 in one very dark-coloured individual of the S, fodiens, and 

 which was sent to me as the S. ciliatus, though it was 

 not quite so uniformly black as my original specimen of this 

 latter, or so bulky for its length, I found 18 caudal vertebrae, 

 being 1 more than in any of the three individuals of the 

 S.fodiens above-mentioned. This must not be considered 

 as conclusive in favour of the S, ciliatus being a species, as 

 we have already seen the number of caudal vertebrae varying 

 by 1, in the case of the S. tetragonurus ; yet it should serve 

 to stimulate to further inquiry. I regret that I have not 

 myself had an opportunity of examining into the value of 

 this character in more specimens. 



I once thought that there were other anatomical pecu- 

 liarities by which this species might be distinguished from 

 the >S. fodiens, to which M. de Selys-Longchamps has made 

 some allusion* ; but having since had reason to suspect that 

 they are not to be relied upon, I forbear dwelling on them. 



(9.) Mus sylvaticus ? — I have two or three times had sub- 

 mitted to my examination specimens of a mouse found on the 

 tops of the Irish mountains, either belonging to this species 

 or very closely allied to it; but those which I have seen have 

 been in too bad condition (merely dried skins) to enable me 

 to decide this point. One of these was taken in the county 

 of Kerry, at an elevation of 2500 feet above the sea-level. 

 The only respects in which they appear to differ from the 

 M. sylvaticus are, in being of a darker colour, smaller, and 

 with some of the relative proportions rather less ; but it must 

 be left for those who have an opportunity of examining a large 

 number in the recent state, to say whether there are any real 

 grounds for believing them to be distinct. On the whole, I 

 am inclined to think that they are only a small variety of that 

 species, somewhat modified in its characters from the peculiar 

 locality which they inhabit. 



(10.) Arvicola amphibius, — Not long since I obtained a 

 small Water Vole, which I consider exactly intermediate 

 * Microniammalogie, p. 29. 



