26 
Psyche 
[March 
valuable phylogenetic characters that it is doubtful whether we shall 
ever be certain of its true affinities. ... It is possible that forms as yet 
unknown will reveal their ancestry more clearly. Until that time, 
however, subfamily rank for the Leptanillinae may as well be main- 
tained. Present opinion seems to favor relating this group to the 
Dorylinae ” 
The larvae of the Leptanillinae do bear certain resemblances to the 
known doryline larvae (Dorylus, Aenictus , Eciton, Cheliomyrmex) : 
the long slender body and the small feebly sclerotized mandibles. On 
the other hand, they differ in the constriction at the metathorax, the 
long hairs on the abdomen, the absence of hairs on the head and the 
shape of the head. But these differences become trivial and insignificant 
beside the three which not only differentiate them from the Dory- 
linae, but also from all other known formicid larvae (160 genera) : 
( 1) the peculiar projection from the ventral surface of the prothorax; 
(2) the reduction of the spiracles from the normal ten pairs to a 
single pair, which is located on abdominal somite III; and (3) the 
shape and stance of the mandibles. 
Subfamily leptanillinae Emery 
Elongate and very slender; slightly constricted at the metathorax; 
anterior end curved ventrally ; remainder of body straight and clavate. 
With a curious complex structure projecting anteroventrally from the 
ventral surface of the prothorax. Only one pair of spiracles, located 
on abdominal somite III; each spiracle opening eccentrically on a 
naked circular area. Body hairs simple ; the minute hairs very 
abundant and uniformly distributed ; a few conspicuous long hairs 
sparsely scattered. Head naked and elongate. Antennae small, 
slightly^ raised, each with two sensilla. Labrum slightly broader than 
long, with the ventral border semicircular; posterior surface spinulose, 
with the spinules in rows. Mandibles apparently turned laterally 
(instead of medially, as is usual with ant larvae) ; feebly sclerotized; 
each with a rather long slender sharp-pointed apical tooth, which 
curves laterally; lateral (=outer) border furnished with several long 
slender sharp-pointed teeth; anterior surface with rows of spinules. 
Labium thin, flap-like and narrowed basally; lateral surfaces sclero- 
tized; each palp a low ventrolateral projection bearing five sensilla. 
Of all the ant larvae studied we have found the Leptanillinae the 
most difficult to process partly because of their small size but chiefly 
because of their extreme slenderness. A slender larva is more apt to 
collapse than a stout one. Furthermore the constriction at the 
metathorax aggravates the difficulty of cleaning and predisposes to 
breakage in that region. As a result processing has often left us only 
