224 
Psyche 
[September-December 
wheel” organs are also striking, and so far as I am aware are un- 
matched among the ants, although the region of the ventral furrow 
between pro- and mesothorax is sometimes modified and apparently 
glandular in some dacetines and a few other myrmicines. 
The 2-segmented antennal club, together with some points of 
habitus (especially coarse sculpture and long, flexuous pilosity, 
plus the antennal scrobes), recalls the neotropical genus Lachno- 
myrmex , but the shape of the trunk in Pilotrochus is completely 
different, the propodeal teeth so prominent in Lachnomyrmex are 
completely absent, and the mandibles in the two genera are very 
different. 
At the moment, all one can say without seeing the winged forms 
and larvae of Pilotrochus, and without knowing something of its 
lifeway, is that it is a member of subfamily Myrmicinae, but one 
not belonging to any of the well-circumscribed “higher” tribes 
(Crematogastrini, Dacetini, Basicerotini, Cataulacini, Attini, etc.). 
Thus, it falls among the mass of generic complexes related to 
Myrmica, Pheidole, Myrmecina, Rogeria, etc., among which tribal 
boundaries are impossible to define for the present, or at least are 
in dispute. 
Considering the revisionary work that must be done before we 
have a rational tribal classification of Myrmicinae, it seems to me 
that nothing would be gained by erecting a new tribe for Pilotro- 
chus, even though for the time being I am able to fit it comfortably 
into any existing myrmicine tribe. 
The generic name is derived from the Greek ‘pilos’ (hair) + ‘tro- 
chos’ (wheel), while the specific name besmerus combines the Latin 
‘bes’ (eight of twelve) with the Greek ‘meros’ (part), in reference to 
the 8-segmented antennae as compared to the primitive myrmicine 
(and formicid) 12-merous condition. 
