664 MURIDA—MUS 
Skull :—Condylo-basal length, 21 to 22-2 (at least), zygomatic 
breadth, 11-2 to 12-6; interorbital constriction, 3-4 to 3-8; breadth of 
brain-case, 9-8 to 10-2; depth of brain-case at middle, 6-8 to 7-2; 
length of nasal, 8 to 8-8; of diastema, 5-6 to 6-2; of maxillary tooth- 
row (alveolar), 3-4 to 3-8; of mandible, 12-2 to 13-8; of mandibular 
tooth-row (alveolar); 3 to 3-2. None of the specimens hitherto 
measured has had the teeth more than moderately worn, skulls with 
much-worn teeth are probably larger. 
Mus feroensis, Clarke, remains to be noticed. This was originally 
described (Proc. Roy. Phys. Soc., Edinburgh, xv., 1904, 163) as a sub- 
species of mzsculus, the type being a female,in the Edinburgh Museum, 
collected by Annandale and Marshall, in August 1903, on Naalso, 
Feroes. In his Catalogue (875), Miller treats this form asa full species. 
Like JZ. muralis, this mouse is remarkable for its large size, its 
hind feet are very robust, their width measured across the bases of the 
outer toes being 5 mm.; the tail is stout, its diameter near the base 
being about 4 mm., instead of 3-6 as in murals, or about 3 as in 
musculus. In colour it is more like musculus than muralis ; its upper 
surface shows “a mixture of rufous and greyish-black (the former 
predominating), the fur being blackish at the base, broadly margined 
with reddish-brown. A number of thinly distributed black hairs are 
also present. Under-surface a mixture of buff and pale grey, inter- 
grading on the flanks with the tints of the upper surface. The ventral 
fur is pale grey at the base, broadly edged with buff” (Eagle Clarke). 
Apart from its larger size (condylo-basal length, 25 to 23-4 mm.), 
the skull (Naals6é specimens) differs from that of musculus only in 
having the rostrum relatively more robust, and the brain-case perhaps 
a little more depressed; the mesopterygoid fossa, in the three skulls 
examined, is as in wsculus. 
Three specimens, in the Copenhagen Museum, from Myggenes, 
another island of the group, have been described by Winge (in Clarke, 
op. cit., 164). These also are “very stout, with exceptionally large 
feet, ‘ wild-coloured’ (z.e. without the sooty colour common in specimens 
taken in large towns);”’ and the mesopterygoid space is contracted 
anteriorly, exactly as in JZ. murals, 
