European Species of the Suhjenus Pity my s. 50'J 



j\ VA. incertus ; or, commc cc squclctte est rapporte 

 par M. de Sel3's-Loiigcliamps j\ son A. duodechncostatus, il 

 s'ensuit que cette espece, dont on ne connaissait que la char- 

 pente osseuse, n'est qu'un A. incertus, ofPrant la siiiguliere 

 anomalie de n'avoir que douze paircs de cotes ct douze vcr- 

 tebres dorsales au lieu de treize . . ." ^. 



The Geneva skeleton agreeing, according to what De Sclys 

 had originally asserted, in every respect with the one from 

 Montpellier, Gerbe concluded further that "A. incertus'' occurs 

 also in the neighbourhood of Geneva ; in a postscriptum to 

 his memoir, however, he states as follows: — "M. de Selys- 

 Longchamps, dans une letti'c en date du 24 juillct dernier, 

 me dit avoir recounu que le squelette A' A. duodeclnicostatus 

 qui lui vient de Geneve se rapporte k VA. Baillonii, ct n'est 

 par consequent point semblable, comme il I'avait avance dans 

 ses Etudes de Micromammaloyie, h. celui du Museum 

 dliistoire naturelle de Paris. Des que cette similitude 

 u'existe pas, il n'y a plus lieu de supposer que le Campagnol 

 incertain doive se trouver dans les environs de Geneve" f- 



What, in 1854, De Selys may have meant by " Arvicola 

 Baillonii " it is difficult to guess, but it does not matter 

 much. Blasius has "Arvicola duodecimcostatus" as a synonym 

 of the Microtus arvalis %, and is herein followed by 

 V. Fatio §. 



The upper and side views of the skull of the Geneva 

 skeleton are represented in the figure 4 bis (pi. iii.) of the 

 ' Micromammalogie/ In the great depth of the skull, back- 

 ward from the rostrum, its longitudinal arching, and the 

 subcylindrical shape of the brain-case it shows so unmis- 

 takably the characteristic form of the skull of Microtus 

 " incertus " from Southern France, so well described by 

 Gerbe ||, that we may safely consider the skeleton to be that 

 of a species of Pttymys, either identical Avith the M. "incertus" 

 as described and figured by Gerbe, or else very nearly related 

 to it ; so that the two skeletons of " Arvicola duodecini- 

 costatus " may, after all, be one and the same species. 



In Fatio's ' Campagnols du Bassin du Leman ' no Pitymys 

 is recorded ; in the same wa'iter's ' Faune des Vertebres de 

 la Suisse ' the only Pitymys mentioned from Switzerland is 



* Rev. et Ma<r. de Zool. (2) vi. pp. 370, 371 (1854). 

 t Op. cit. p. 608. 



\ J. H. Blasiu:^, * Niiturgesch. d. Saugethiere Deiitschlands . . .,' p. 379 

 (1857). 



§ V. Fatio, ' Faune des Vertebras de la Suisse,' i. p. 234 (1869). 



11 Ilev. et Mag. de Zool. (2) vi. pp. 368, 360, pi. xi. fig.s. 1 & 2 (18o4). 



