Mimicry of Ants by other Arthropods. 309 
5. Mimicry of ants by other Arthropods which always 
live with their hosts: This section includes the Myrmecoid 
Synoeketes, of which the best examples are the guests of 
the Driver ants (Dorylii) of tropical Africa and Asia, and 
the legionary ants (Ecitonti) of the warmer portions of 
America. The species are principally Staphylinid beetles, 
and among them are some of the most remarkable ant- 
mimics in the world. As their hosts have no fixed abode 
these Synoeketes live as camp-followers, moving from place 
to place in company with the ants, and feeding on the 
plentiful booty obtained by them. Perhaps the most 
wonderful of all is the Staphylinid beetle Mimanomma 
spectrum, a Doryline guest, whose whole body is modified 
in the most extraordinary manner, to imitate that of its 
hosts. 
Mimeciton pulex is also a very curious insect which lives 
with an Eeiton in Brazil. Wasmann, to whom we are 
indebted for our knowledge of nearly all these Doryline 
guests, considers that the form and hairiness of Mimeciton 
are for the purpose of deceiving its hosts, whilst its ant-like _ 
colour protects it from outside enemies when running along 
in company with Eciton. As the Doryline ants are blind, 
but possess a keen sense of touch, it is highly probable 
that in such cases as this Wasmann’s interpretation is 
correct. 
6. Mimicry of ants by other Arthropods which always 
live with their hosts, and are fed and licked by them—these 
are the true guests, or Myrmecoid Symphiles. The 
Staphylinid beetle Lomechusa is always to be found in 
parts of the nest where the ants are thickest. Here it is 
to be found sitting amongst and crawling over the ants, 
and when at rest practically indistinguishable from them. 
The reason being that the light which is reflected from the 
concave sides of the thorax appears to the eye like the 
narrow back of an ant, and the rolled-up abdomen of the 
beetle reflects the light in the same way as the rounded 
gaster of a large ant. The species of another Staphylinid 
genus Atemeles are not only ant-like, but also mimic the 
ants’ movements. When an Alemeles desires to be fed 
it not only solicits an ant by tapping with its antennae as 
_ does Lomechusa, but it further mimics the actions of its 
hosts by stroking the side of the head of the ant with its 
front feet. These actions are also performed by the larva 
of Xenodusa, the American representative of Lomechusa, 
