interesting habits have been closely studied by a number of naturalists. Mason bees of the genus Osmia are also small and brilliantly colored, blue or green, having habits somewhat akin to those of Megachile. A European species is said to build her cells of mud, depositing them in the empty shells of snails. Many other species of this genus Osmia, in various parts of the world, possess habits full of interest to us, that have been described in the books with greater or less detail. Then we have the less intelligent types of those bees that burrow in the ground, that are solitary, and leave their young to look out for themselves. These fossorial bees see their types in such forms or species as the common Andrena vicina, that I have observed in many parts of New England. Parasitic bees, called cuckoo bees (as Nomada sex-fasciata), prey upon these fossorial forms, such as Andrena or its allies of the genus Halictus and others, by laying their eggs in their nests. They are also infested by numerous other parasites, such as by certain ichneumon flies and oil beetles (Meloë), and others. Some of the South American bees are destitute of stings (Melipoma, Trigona), and I have frequently seen a large bee here near Washington that does not sting. It has the appearance of a Bombus, but the fore part of the head is nearly all of a very pale yellow, almost white.
Carder bees (Bombi muscorum) are known to all frequenters of open fields and meadows, after the haying season has commenced. A popular writer at hand says: "They select for their nest a shallow excavation in the ground about a foot in diameter, or, if such a one is not to be found, they make one with prodigious labor. This they cover over with a dome of moss, or sometimes with withered grass. They collect their materials by pushing them along upon the ground, working backward like the tumblebugs. Frequently in the spring a single female founds a colony, and by perseverance collects the mossy covering in the way described; later in the season, when the hive is populous and can afford more hands, there is an ingenious division of this labor, A file of bees, to the number sometimes of half a dozen, is established from the nest to the moss or grass which they intend to use, the heads of all the file of bees being turned from the nest and toward the material. The last bee of the file lays hold of some of the moss with her mandibles, disentangles it from the rest, and, having carded it with her fore legs into a sort of felt or small bundle, she pushes it under her body to the next bee, who passes it in the same manner to the next, and so on till it is brought to the border of the nest—in the same way as we sometimes see sugar loaves conveyed from a cart to a warehouse by a file of porters throwing them from one to another. The elevation of the dome, which is all built from the interior, is from four to six inches above the
