226 



THE SCOTTISH NATURALIST 



2. MUS MUSCULUS, Linnaeus. 

 (The House Mouse.) 



A. Butt of Lewis. — Nine House Mice were collected at 

 this place by Dr Eagle Clarke ; these mice were leading a 

 wild outdoor life at some considerable distance from any 

 houses. The following are the dimensions : — 



The external measurements given above are as made by 

 the collector : as regards the females Nos. 5 and 12 we think 

 the hind-foot without claws cannot have measured more 

 than 20 and 18-5 mm. respectively. Twelve more or less 

 complete skulls have been sent with this collection, but some 

 slight confusion on the part of the preparer appears to have 

 been made in numbering them, so that we are not quite cer- 

 tain as to the association of the individual skins and skulls. 

 Nine skulls are complete, viz., "No. 3, Butt of Lewis 1914," 

 condylo-basal length 19-4, teeth very slightly worn; "No. 

 4," c-b. 1. 19-2, teeth hardly worn ; " No. 5," c-b. I. 23, teeth 

 moderately worn; "No. 2," c-b. 1. 22-5, teeth much worn; 

 "No. 7," c-b. 1. 2I-I, teeth half worn; "No. 8," c-b. 1. 22-2, 

 teeth much worn; "No. 9," c-b. 1. 21-9, teeth much worn; 

 "No. 12" (? No. 13), c-b. 1. 19-5, teeth hardly worn; "No. 

 13" (? No. 12), c-b. 1. 20-3, teeth half worn. 



In colour these mice are quite like ordinary nmscuhis in 

 out-door pelage, their bellies being dusky instead of light 

 coloured as in M. muralis and spicilegiis. The flesh measure- 

 ments are large but do not exceed the known maximum for 



