The populations of Sorex araneus collected from Lac des Bouillouses and Etang de Balcere, both localities near Mount Carlit, Pyrenees Orientales, France, belong to the Western European Phylogenetic Group, WEPG (Searle 1984), and show a primitive karyotype for this group, with the metacentrics gm, hi, and jl only.
The northern extension of the WEPG metacentric gm in Sweden, in populations otherwise characterized by metacentrics of different origin like hn (Fredga and Nawrin 1977), and the relatively independant cline of frequency of pr across the hybrid zone between Oxford and Hermitage race in England (Searle 1986b, 1988) can also be interpreted as indications of such processes.