686 



MlCEOTUS AHVALIS MEKIDIANUH Miller. 



1908. Microtus arvalis vicridianus Miller, Ann. and Mag. Nat. Hist. 



8tb ser., i, p. 197, February, 1908. Type in British Museum. 

 1910. Microtus arvalis mcridia7ins Trouessart, Fauna Mamm. d'Europe, 



p. 174. 



Tyj)e locality. — Near Biarritz, Basses-Pyrenees, France. 



Geographical distribution. — South-western France, in and near 

 the Pyrenees. 



Diagnosis. — Like Microtus arvalis arvalis but larger (hind 

 foot, 15 '8 to 16*6; condylobasal length of fully adult skulls, 

 about 25' 5 mm.), and shghtly more yellowish. 



Colour. — The colour so nearly resembles that of the typical 

 race as to require no detailed description. In general there 

 appears to be a tendency toward more conspicuous suffusion of 

 sides and underparts with buff. 



Shull and teeth. — Apart from their greater size the skull and 

 teeth resemble those of M. arvalis arvalis. In some specimens, 

 however, the brain-case is unusually short, its outline almost 

 circular. 



Measurements. — External measurements of type (adult female) : 

 head and body, 1 1 5 ; tail, 32 ; hind foot, 1 6 • 6 ; ear, 12. Average 

 and extremes of four adult individuals from the type locality : 

 head and body, 106-2 (102-115) ; tail, 31-7 (30-34); hind foot, 

 16*1 (15* 8-1 6 • 6) ; ear, 11*2 (10-1 2). For cranial measurements 

 see Table, p. 689. 



Specimens examined. — Eleven, from the following localities in south- 

 western Prance: Port6, Pyrenees-Orientales, 1; Pic du Midi, Hautes- 

 Pyren^es, 1 skull (Lataste) ; Biarritz, Basses-Pyr^ndes, 8 ; Pyrenees, no 

 exact locality, 1. 



?. Porte, Pyr^nees-Orientales, 0. Thomas (p). 8.9.1.70. 

 France. [A. Robert.) 



2 c5, 4 ?. Biarritz, Basses-Pyrenees. J. F. Davison (c & p). 6. 6. 4. 23-28. 



(6. 6. 4. 26. Type of subspecies.) 



1. Pyrenees. Baron E. de S^lys- 45. 7. 5. 6. 



Longchamps (p). 



1. Tomes Collection. 7. 1. 1. 137. 



Microtus arvalis duplicatus Rorig and Borner. 



1905. \_Arvicola arvalis] forma duplicata Eorig and Borner, Arbeiten aus 

 der Kaiserlichen Biologischen Anstalt fiir Land- und Forstwirt- 

 schaft, v, Heft ii, pi. v. 



Type locality. — Rossitten, Ostpreussen, Germany. 



Geographical distribution. — Shores of the Baltic in north- 

 eastern Germany. Limits of range not known. 



Diagnosis. — Like Microtus arvalis arvalis but attaining a 

 larger size (hind foot, 17 to 18 '6 mm. ; condylobasal length of 

 skull in fully adult individuals about 25 to 25 * 5 mm.) ; colour 



