88 THE ENTOMOLOGIST’S RECORD. 
the host’s outward appearance. Both active and passive mimicry 
assist the genuine intercourse of the guest, as well as its simple tolera- 
tion. The former is best exhibited by the Staphylinid genus Atemeles, 
which deserves the first prize for active mimicry, as they summon 
their hosts at feeding time in the same manner most generally employed 
by ants (see pl. fig. 1). They not only make use of their antenne as 
do other true guests (Claviger, Lomechusa, Amphotis), but they also use 
their fore feet, which they lift up to stroke the feeding-ant on the side 
of the head, in the same way as does an ant asking for food. Active 
mimicry in many Brazilian Heiton guests probably assists them to be 
tolerated by their hosts. The shape of their antenne for example, in 
Ecitomorpha arachnoides and simulans, is a sure sign of intercourse, 
although they do not possess the tufts of yellow hair, or any of the other 
characteristics of hospitable intercourse. In Mimeciton pulex it is 
doubtful whether the similarity of the antenne has any connection 
with hospitable intercourse. Even in the genus Myrmedonia, which 
dwell with Lasius fuliginosus as hostile persecuted lodgers, I haye 
often seen individuals stroke the ants with their antennae, in their 
efforts to appease the latter. 
The similarity of the outward appearance calculated to deceive the 
ant, even in the genuine guests, is only one of the means employed by 
them to make themselves pleasant to and taken care of by the ants. 
No passive mimicry is to be found in the whole family Clavigeridae, 
which belong, as has been already stated, to a higher form of Symphilie. 
They are always of that greasy shining red hue, sometimes darker, 
sometimes lighter, which is the most usual colour of true guests. It 
is of no consequence to them as far as their colour is concerned, 
whether they live with black or yellow ants. The peculiar shape of 
their bodies is also always the same in the whole group, and never 
imitates the shape of their hosts. Their guest patent is assured them 
by their aromatic charms, which give pleasure to their hosts’ sense of 
taste. Hven their active mimicry, t.e., the imitation of the movements 
of the ants’ antenne, is much more imperfect than that of Atemeles and 
Lomechusa. 
Lastly we mentioned among the adaptive characters of Myrmeco- 
phila and Termitophila a protected form which renders the guest 
unattackable by its host. This protected form is naturally only found 
in hostile and indifferently cared-for guests, so that as they are 
unattackable they are left in peace. Tropical American Staphylinidae, 
belonging to the genus Xenocephalus, are the best examples of this 
kind. They live in the company of the robber wander-ants (Eciton) 
and follow in their suite in the same way as the mimicking species of 
Ficiton guests. Instead of deceiving their hosts with mimicry, they 
hide themselvs under a protecting roof, which is shaped like a shield 
and covers them completely with the exception of the ball-shaped 
pointed abdomen. It reaches to the ground, completely covering the 
head, antenne, and legs of the beetle, which gives it somewhat the ap- 
pearance of a molluse-crab (Limulus), or of a pre-historic Trilobite. Dr. 
Joeldi once saw near Rio de Janeiro such a Xenocephalus, walking quietly 
and unmolested in the midst of a column of marching wander-ants. 
What makes them still more unattackable, their legs are quite flat and 
furnished with long spines, the head is pressed downwards under the 
thorax into a nearly pointed corner, so that the mouth comes between 
