448 Trans. Acad. Sci. of St. Louis. 
The other flowers have the nectar so situated that it is con- 
venient for short-tongued insects, and these flowers agree in 
showing a preponderance of Apidae, Andrenidae and Diptera. 
Early in the spring the anthophilus insect-fauna consists 
mainly of these insects. Later in the season bees and flies 
come in competition with the lower Aculeate Hymenoptera, 
which become abundant. Accordingly, these insects show a 
larger proportion on the late flowering Geum album than on 
any other species. The earlier species show quite a number 
of bees of the genus Andrena. The time of flight of all of 
these species of Andrena is over before Geum album comes 
in bloom, and, consequently, the list of visitors shows none 
of them. Andrenas would he expected to occur on Fragaria, 
and probably do, but my list is quite fragmentary. Miiller 
found one Andrena on F’. vesca. 
The usual colors of the Rosaceae are white (13 species, 
table II.) or yellow (5 cases), ‘colors characterizing flowers 
adapted to miscellaneous insects. Pyrus and Rosa show 
marked departures from the ordinary colors, and, as noted 
above, are adapted to bumble-bees. 
_ Except in the cases of the species adapted to Apidae, these 
bees are not very abundant on the flowers. Of the Apidae 
which fly throughout the season, we have Apis and Ceratina. 
Bombus females occur on the early species, and the workers 
appear later on fosa. On the earlier flowers we find the 
early flying species, such as Anthophora, Synhalonia, Osmia, 
Nomada and Panurgus? Later species show Phileremus, 
Stelis and Calliopsis. 
The.flowers being of rather simple structure, with easily 
accessible nectar and numerous exposed stamens, are partic- 
ularly well suited for the short-tongued bees — Andrenidae. 
These consist mainly of Andrena and Halictus. Early bloom- 
ing species show the single early Colletes inaequalis. A little 
larer we find Agapostenion, Augochlora, Prosopis and 
Sphecodes —a few species of each. The males of Halictus, 
and the allied genera Agapostemon and Augochlora, do not 
appear until late in the season. Accordingly, the early lists 
show nothing but females of these genera, and we find males 
of Halictus and Augochlora only on the late flowers of 
Geum album. 
