AEVICOLA 741 



Skull and teeth. — The skull resembles that of Arvicola terrestris 

 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* slightly larger than in the Scandinavian species, 

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

 larger. 



Measurements. — Average and extremes of five adults from 

 Lugano, Ticino, Switzerland: head and body, 180-6 (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 l(i. Adult female from Ceresole dAlba, 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 S, 2 ?. Locarno, Ticino, Swit- 0. 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). 46. 1. 9. 20. 



ARVICOLA ILLYRICUS Barrett-Hamilton. 



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



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

 1910. Arvicola illyricus Miller, Proc. Biol. Soc. Washington, xvin, 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 buff. 



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 



