THE DORMOUSE OR SLEEPER 361 
Geographical variation:—As shown by the Italian and Sicilian 
forms, pulcher and speciosus, there is evidently a tendency to brighter 
tints and more striking contrasts in the south. In 1900 (see Synonymy), 
I separated the British form from JZ. a. avellanarius on the ground that, 
whereas each is more dully coloured than MW. pulcher, the British, which 
I named JZ. a. anglicus, appears to have the upper side more brilliant, 
a whiter breast, and a thicker and shorter tail than the typical form. 
Miller, working more recently, is unable to accept this conclusion ; but 
there is room for further study, as no series of British dormice is available 
for examination. 
DIMENSIONS IN MILLIMETRES :— 










Tail (with- | Hind foot Ear 
Hee and out terminal] (without (greatest 
ae hairs). claws). length). 
MALES :— 
] 
1. Purchased in London, 15th December 
1898 (W. Dodson) . . a . 71 s- 16 13 
. Honiton, Devon, 22nd August 1904 
(G. C. Shortridge) . ; 75 68 18 13 
FEMALES :— 
1. Wendon Lofts, Saffron Walden, Hees 
8lst May 1894 85 61 15 
2. Colchester, Essex (G. 8. Miller) . . 77 55 16 11 
3 and 4. Purchased in London, 15th |) 73 62 16 12 
December 1898 (W. Dodson) . AE 55 17 12 
SEX UNCERTAIN :— 
1. (No. 99.11.27.6 of British Museum 
Coll.), Bedford Purlieus, Thorn- 
haugh, Northamptonshire, 5th 
January 1895 (H. H. Slater); type 
of M. avellanarius anglicus . c 86 57 16 



Skull :—Greatest length, 22-7 to 24-5 ; condylo-basal length, 21-8 to 
23; breadth at zygomata, 13-2 to 14-4; inter-orbital breadth, 3-0 to 3-4; 
mastoid breadth, 11 ; depth of brain-case at middle, 8-0; greatest length 
of nasals, 6-8 to 7-2; of diastema, 6 to 6.2; of mandible, 13 to 14; of 
maxillary tooth-row, 4:8; of mandibular tooth-row, 4-2 to 4-4. 
Weight in grammes:—Rabus (Zool, Garten, 1881, 321-325, trans- 
lated in Zoologist, 1882, 161-164) found that this varies between 23 and 
43. It increases during the season of activity, especially in September, 
and attains its maximum just before the commencement of hibernation, 
It then decreases,! a female having dropped from 37 to 26 during 
hibernation lasting from 19th October to 27th March, or about at 
the rate of 2 a month. The September increment amounted in 
1 Some naturalists have curiously supposed that both fat and weight increase 
during hibernation. 
VOL. II. 2A 
