ARVICOLA 741 



Skull nnd teetli. — The skull resembles that of Arvicola terrestns 

 in size and general appearance, but the brain-case is deeper and 

 noticeably longer in proportion to its breadth, the general outline 

 thus approaching that of the large numbers of the group. 

 Auditory bulL-e slightly larger than in the Scandinavian species, 

 but not peculiar in form. Teeth as in A. ierrestris, but slightly 

 larger. 



Measurements. — Average and extremes of five adults from 

 Lugano, Ticino, Switzerland: head and body, 180 -G (174-191); 

 tail, 87-8 (84-90); hind foot, 27-7 (27-29). Adult male and 

 female from Locarno, Ticino, Switzerland : head and body, 

 179 and 171; tail, 102 and 98; hind foot, 29 and 27-5; ear, 

 15-5 and IG. Adult female from Ceresole d'Alba, Turin, Italy : 

 head and body, 163; tail, 90; hind foot, 29. For cranial 

 measurements see Table, p. 743. 



Specimens examined. — Twenty-nine, from the following localities : — 

 Switzerland : Lugano, Ticino, 19 (U.S.N.M. and Mottaz) ; Locarno, 



Ticino, 4. 

 Italy: Casaleone, Verona, 1 (U.S.N.M.); Modena, 3; Ceresole d'Alba, 



Turin, 1 (Turin) ; no exact locality, 1. 



2 6,2 9. Locarno, Ticino, Swit- O. Thomas (c & p). 2. 7. 1. 2-5. 

 zerland. 



9, 2juv. al. Modena, Italy. Marquis G. Doria (p). 90.3.5.1-3. 



1. Italy. Purchased (Brandt). 4G. 1. 9. 20. 



ARVICOLA ILLYRICUS Barrett-Hamilton. 



1899. Microtus musignani illyricus Barrett-Hamilton, Ann. and Mag. Nat. 



Hist., 7ch ser., in, p. 225, March, 1899. Type in British Museum! 

 1910. Arvicola illyricus Miller, Proc. Biol. Soc. Washington, xviii p 21 



March 23, 1910. 

 1910. Arvicola illyricus Trouessart, Faune Mamm. d'Europe, p. x. 



Type locality. — Bosnia, no exact locality. 



Geographical distribution. — Bosnia. Limits of range not 

 known. 



Diagnosis. — Similar to Arvicola italicus, but underparts with 

 a decided whitish wash. 



Colour. — The colour is in all respects similar to that of 

 Arvicola italicus, except that the chest and belly are a whitish 

 grey, with only the faintest tinge of bufl'. 



Skull and teeth. — -The imperfect skull of the type shows 

 nothing to distinguish it from that of Arvicola italicus. 



Measurements. — -Type: hind foot, 30; ear, 15. For cranial 

 measurements see Table, p. 743. 



Specimen examined. — The type. 



Remarks. — The Bosnian water vole is so similar to Arvicola 

 italicus that the two animals will not improbably prove to be 



