78 



Miscellaneous. 



in front; of the inner series only two or three could be counted, 



others had probably been present. The outer row m the lower jaw 

 consisted of about sixteen teeth on each side, without counting the 

 long ones in front. 

 The following: are the dimensions of the specimen : — 



° inche 



Total length • ^iV 



Height over middle of anal, rather more than -^ 



Head, length IT 



, height TO 



Eye, diameter ^- 



Maxillary i o 



Teeth, length of fourth pair under jaw 5^0 



First dorsal, height and length of base ■^\ 



, distance from muzzle -j^ 



Second dorsal, distance from muzzle l-fiy 



, distance from first dorsal 



, length of base 



, height A 



Pectorals, length -fij 



, width of base tV 



, distance from muzzle 1 



Ventrals, length -^j^ 



Anal, distance from muzzle . . l^o 



, length of base j'V 



, height in front -fxs 



Caudal, length -^ 



Air-bladder, length i 



10 



MISCELLANEOUS. 



Migration of Lemmings. 



To the Editors of the Annals of Natural History. 



Gentlemen, — In a recent Number of the ' Annals and Magazine 

 of Natural History,' the subject of the migration of Lemmings was 

 discussed, and some causes of it, propounded by M.Guyon, mentioned, 

 none of them being quite satisfactory. 



I have discovered that rats in England frequently abandon good 

 quarters, where they have plenty of food and are unmolested by man 

 or carnivora, and that the cause of their doing so is that they are 

 plagued with insect vermin — fleas, lice, and ticks. 



Knowing that insects are a plague to man in Lapland, I beg to 

 suggest the question whether the occasional migrations of Lemmingg 

 may not be caused by the unusual abundance of insect vermin of the 

 above-mentioned or other kinds. 



Perhaps I may mention here something I have observed about 

 Dormice. In some parts of Suifolk they are very numerous, and 

 are called Sleep-meece by the labourers. In other parts, if turned off 

 in woods equally abounding in oaks and hazel, they seem not to in- 



