The elegant genus EPEOLUS occurs in our own species throughout northern Europe, as high as Lapland, and is found also at the southern extremity of the continent of the Old World, at the Cape of Good Hope. It has been brought from Sicily, and other species come from Siberia. The genus in America passes down from the United States, by way of Mexico, to the Brazils, where it crosses the southern continent, having been transmitted from Chili. It is very limited in the number of its species, considering its wide diffusion, for not more than twenty are registered. It is almost identical in distribution with the genus _Colletes_, upon which it is with us parasitical. The species are never so large as those of the preceding genus, _Melecta_. The genus STELIS is limited both in number of species and distribution, although the spots whence it has come are wide apart. Our own species are found throughout France and northern Europe, as far as Finland. Other species occur in North America, and the Brazils, but the whole number yet described is under ten. The remarkable form in both sexes of the genus CÆLIOXYS occurs in identity with our own species throughout France and Austria, and spreads north to Finland and Russia, and through all the intervening countries. It is singular that it should not be recorded from southern or south-western Europe, as it is found in Oran. Other species of the genus have been found in northern Africa, Egypt, and Algeria. On the western coast of Africa it has been caught on the Gambia, at Sierra Leone, and on the coast of Guinea. It doubles the Cape of Good Hope, where it is found extending its range to Port Natal. From Asia we have it from Turkey, and again from India. It has been sent from the hither side of South America, from the Brazils, and separately from Pará, and occurs at Cayenne, and in the West India Islands, Cuba, and St. Thomas’s, and extends as high in North America, through the United States, as Canada. It is quite probable that it has as wide a range as the bees upon which it is parasitical (_Megachile_), although it has not yet come from such extensively-spread localities. More than fifty species are known, but some of our own have not yet been enumerated amongst those found elsewhere.