1 1 02 The American Naturalist. [December, 
constantly moving their feelers, and experimenting with everything. 
If one be attacked by a hostile ant, it first seeks to pacify its antagonist 
by antennary caresses, but if this is unavailing it emits a strong odor 
which appears to narcotize the ant. Wassmann describes how the ants 
feed the Atemeles, and are caressed and licked for their care ; how one 
Atemeles feeds another, or even as a rarity one of the hosts. Yet the 
beetles feed independently on sweet things, dead insects, and even the 
unprotected young of the ants. The guests are licked and cleaned by 
the hosts, as well as vice versa; but the beetles are in reality quite 
dependent upon the ants. 
As to Somechusa, it is represented in Central Europe by a single 
species, S. strumosa, which is almost always found with Formica san- 
guinea, though occasionally with other forms. This beetle is much 
larger, plumper, and more helpless than Atemeles ; its odor is different 
and very like formic acid ; its relations to the hosts are more passive, 
yet it can feed independently, for instance, on the larvae and pupae of 
The other guests are rather pests than pets. They almost all live on 
animal food, are often protected simply by prestige or by their odor. 
The minute Oligota, Homalota talpa, Myrmecoxenus, Monotoma, 
Histeridae, the small guest-ant Formicoxenus in the nests of Formica 
rufa, etc., appear to escape unnoticed. * 
On a change of abode, the myrmecophilus insects follow their 
guests, or, as in the case of Somechusa and Atemeles, they are taken 
with them by force. While the ants themselves are well known to be 
very exclusive, the guests can be shifted from nest to nest or even from 
species to species. As Wassmann says, the guests seem to have " inter- 
national relations." 
In commenting upon the above facts. Prof. Emery regards it as 
certain that the semi-domesticated, and in one sense parasitic, forms 
like Atemeles and Somechusa, are descended from thievish forms. 
They retain some of the original traits, just as dogs and cats do in 
their recently acquired tamed %X.2Xt.— Journal Royal Microscopical 
A New Harvest-Spider.— In a lot of material collected in War- 
ren county, Ohio, during the summer of 1889, I find a single female 
specimen of an undescribed species of Oligolophus, a genus of Phalan- 
giinae of which we have as yet recorded for the North American fauna 
but a single representative — O. pictus (Wood). This latter differs 
greatly from the one under consideration, for which the specific name 
