1910] Wheeler — North American Forms of Lasius umbratus 235 Odinia picta Loew. There seems to be no record of the occurrence of this species since it was described from Georgia. A specimen was taken by the writer at Glenside, Pa., June 2, 1895. A second specimen from Branford, Conn., June 23, was collected by Mr. H. L. Viereck. THE NORTH AMERICAN FORMS OF LASIUS UMBRA-TUS NYLANDER.i By William Morton Wheeler. Like many other ants that are peculiar to the north temperate zone, Lasius umbratus is very widely distributed and presents a number of local subspecies and varieties. In the Old World it ranges from England to Japan, through northern and central Eurasia; in North America from Nova Scotia and the Atlantic States to the Rocky Mountains and will probably be found on the Pacific Coast, at least in the mountains of California or at lower elevations in Washington and Oregon. According to Forel and Emery the species is represented in Europe by four subspecies, namely, the typical umbratus Nyl., mixtus Nyl., affinis Schenk and bicorji is Forster. To these Ruzsky has added a fifth, e.racutus, from Oriental Russia. To judge from a female specimen in my collection, the Japanese form is indistinguishable from the typical umbratus. Transitional forms which Forel has called mixto-umbratus occur in Switzerland, and others which Ruzsky has called umbrato-affinis have been taken in eastern Russia. Mayr cited three forms from the United States: mixtus, affinis and bicornis, but Emery has shown that the first of these differs slightly from the European mixtus and had been previously described by Walsh as Formica aphidicola, and that the last is a distinct subspecies which he has called minutus. He was unable to find affinis among his American material and I have been equally unsuccessful. This form, there-fore, is probably not represented on our continent. More recently "Contributions from the Entomological Laboratory of the Bussey Institution, Harvard University, No. 30.