664 MURID^— MUS 



Skiill: — Condylo-basal length, 21 to 222 (at least), zygomatic 

 breadth, ii-2 to i2-6; interorbital constriction, 3-4 to 3-8; breadth of 

 brain-case, 9-8 to io-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 fasroensis, Clarke, remains to be noticed. This was originally 

 described {Proc. Roy. Phys. Soc, Edinburgh, xv., 1904, 163) as a sub- 

 species oi Muscu/uSithe type being a female, in the Edinburgh Museum, 

 collected by Annandale and Marshall, in August 1903, on Naalso, 

 Faeroes. In his Catalogue (875), Miller treats this form as a full species. 



Like M. 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 muralis, or about 3 as in 

 musculus. In colour it is more like niusculus th3.n muralis; its upper 

 surface shows "a mixtuie 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 (Naalso specimens) differs from that of musculus only in 

 having rhe rostrum relatively more robust, and the brain-case perhaps 

 a little more depressed ; the mesopterygoid fossa, in the three skulls 

 examined, is as in musculus. 



Three specimens, in the Copenhagen Museum, from Myggenses, 

 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 ' {i.e. without the sooty colour common in specimens 

 taken in large towns)," and the mesopterygoid space is contracted 

 anteriorly, exactly as in M. muralis. 



