270 Rev. L. Jenyns on some of 



rather longer, reducing the ears to nearly its own length ; and 

 the hair on the under parts was not only longer and thicker, 

 but darker at the roots, a considerable portion from the base 

 upwards being dusky. 



Similar to these last described are several individuals in 

 the Museum of the Zoological Society, which, being shown 

 to M. de Selys-Longchamps during his visit to London in 

 1839, he was at first inclined to think different from the 

 ^. arvalis of his work. However, in a subsequent commu- 

 nication by letter to this country, he writes word that he has, 

 since the publication of his 'Etudes de Micromammalogie,^ 

 obtained information with respect to the Mus agrestis of 

 Linnaeus, found in Sweden ; and he says that it appears to 

 be the same as his Arvalis, only the colour of the Swedish 

 individuals is rather darker, and the upper part of the tail 

 darker than the under. He then adds, that he had observed 

 a similar local variety in the collection of the Zoological 

 Society, and that he does not think that it is specifically 

 distinct from the common Arvalis. 



That this opinion is correct I have but little doubt ; and I 

 conceive that the variation in the length and colour of the 

 fur is probably dependent upon season, though the difference 

 of colour in the feet and tail in some specimens can be traced 

 to no particular cause. 



(12.) Arvicola neylecta, Thompson. — For some time I was 

 inclined to consider also as a mere variety of the A. arvalis 

 some specimens from Scotland, the first of which I received 

 from Mr. Thompson so long back as the spring of 1839. To 

 the kindness and liberality, however, of this gentleman I have 

 lately been indebted for permission to examine a much larger 

 number of the same kind oi Arvicola collected last autumn at 

 my request, and after a close comparison of both sexes of dif- 

 ferent sizes with English individuals, I am inclined to think 

 that they deserve to rank as a distinct species. I should say 

 that Mr. Thompson had been previously led to form this opi- 

 nion, and that it was also the opinion of M. Agassiz, to whom 

 he showed specimens, on the occasion of that naturalist's visit 

 to Scotland last summer. I have accordingly adopted Mr. 

 Thompson's own name neglecta for this species, of which he 

 is the discoverer, and which he has merely put into my hands 

 to describe. 



Mr. Thompson informs me that this new Arvicola is com- 

 mon on moors in two localities in the district around Megar- 

 nie Castle in Perthshire, where he first observed it himself, 

 whilst shooting, in 1829. He has also received it from some 

 spoi'ting friends at Aberarder in Liverness-shire. At this last 



