France is curiously divided in two in the direction of a diagonal

Le Havre -Toulon.

The main departments concerned are:

Aisne (Decret, Morellon, Pécheux),
Aveyron (Barroul, Calmel, Devic, Domergue, Duranton, Teyssedre),
Côte-d'Or (Bailly, Bouzereau, Simard, Tixier),
Creuse (Bord, Boussac, Lhomet, Morellon),
Finistère (Gales, Keralum),
Ille-et-Vilaine (Buan),
Maine-et-Loire (Bidet, Blourdier, David, Davy, Jamme, Roullier),
Moselle (André, Bigarel, Sibille, Théobald),
Oise (Ballin, Deforceville, Denisart, Dobigny, Fournier),
Paris and Ile-de-France (Domergue, Gomé, Grimont, Luquin, Sisco).