Preliminary note on the occurrence of Carychium tridentatum Risso in the Netherlands

Among my rather extensive material of Carychia from various countries in Europe, recently kindly examined by Mr. Hugh Watson (Cambridge), Carychium tridentatum Risso was found in 3 specimens from Vogelenzang, province of Zuid-Holland, leg. P. P. de Koning, 18-VIII-1931 (Rijksmus. Natuurl. Hist., Leiden). As far as I know this is the first record for the Netherlands. Carychium tridentatum Risso (an auctorum?) seems to be widely distributed in Europe, but appears to live excluselively in woods, contrary to C. minimum O. F. Müll., which occurs in open country, along lakeshores, in moors, etc. As my researches for minute species have hitherto mainly been devoted to the fauna of woods, it is clear why I found C. tridentatum already in 45 localities in Denmark. In some of our dark beech-woods 100% of the Carychia belong to this species. C. tridentatum is also present in my material from Northern France, Germany, Austria, Sweden, Latvia and Lithuania.