1928] 
The Larva of Leptanilla 
89 
finds that the larva of Leptanilla is very aberrant, and the 
characters of the adult are either quite unlike those of other 
Dorylinae or only superficially similar and due to convergence, 
or similarity of subterranean habits.” (page 335) 
The larva of Leptanilla does bear certain resemblances to 
the known doryline larvae ( Dorylus , Aenictus, Eciton, Chelio- 
myrmex) : the long, slender, subcylindrical, orthocephalic, nearly 
straight body, narrowed progressively from behind forward; the 
small, feebly chitinized mandibles; the absence of a tropho- 
rhinium on the mouth-parts. On the other hand, it differs in the 
constriction at the first abdominal segment; the long hairs on 
the abdomen, especially the extremely long pair at the posterior 
end; the absence of hairs on the head; the shape of the head, 
which in the Dorylinae is suborbicular. But these differences 
become trivial and insignificant beside the four which not only 
differentiate it from the Dorylinae, but also from all other known 
formicid larvae (130 genera). Leptanilla is unique in the (1) 
possession of the plowshare-like structure on the ventral side of 
the prothorax, (2) the “tympanum” on either side of the fourth 
abdominal segment and (3) the toothed flaps of the labrum and 
(4) in the position of the mandibles, which are directed down- 
ward and somewhat backward along the sides of the labium 
instead of lying across the front of the labium with their apices 
nearly touching or crossed. 
These aberrant characters of the larva of Leptanilla support 
the contention of Dr. W. M. Wheeler (quoted above) that the 
tribe Leptanillini should be removed from the Dorylinae and 
raised to the rank of a subfamily. 
Concerning the functions of these peculiar structures nothing 
is known. The plowshare-like structure on the prothorax might 
be an exudatorium; the “tympanum” suggests an auditory 
organ. If the larvae of this rare ant (or of any related species) 
are ever collected again, they should be kept alive in an artificial 
formicary and studied for the purpose of solving these problems. 
Also some specimens should be suitably killed and fixed for 
histological examination. 
It is interesting in this connection to note that another 
