XV. Observations on the Structure of some Australian 
Lepidoptera Homoneura, including the Diagnoses 
of two new Families. By A. JErFERIS TURNER, 
M.D., F.E.S. 
[Read October 5th, 1921.] 
Text Figures 1-8. 
Tue order Lepidoptera is naturally divisible into two 
sub-orders of very unequal size, but separable by im- 
portant anatomical characters. In the Homoneura or 
Jugata (1) the neuration of both wings is substantially 
the same: (2) a jugum is developed at the base of the 
dorsum of the fore-wings as the chief, or at least a most 
important part of the wing-coupling apparatus: (3) the 
spiral proboscis or tongue so characteristic of the Lepido- 
plera is never developed. In the Heteroneura or Frenata 
(1) the neuration of the hind-wings is reduced by the 
radial sector beg unbranched (Comstock and Needham, 
p. 81), so that three veins (R3, R4, R5) normally present 
in the fore-wing are never developed: (2) there is no 
jugum, but the frenulum of the hind-wings articulates 
with a special apparatus consisting of a subdorsal reti- 
naculum in both sexes, and in addition a subcostal reti- 
naculum in the ¢ sex, except in groups in which these 
structures have been lost. By “lost ’’ I mean that these 
groups can be inferred with considerable certainty to have 
descended from forms in which these structures were 
present: (3) A spiral proboscis or tongue is_ present 
except in groups in which it has been lost. The absence 
of a proboscis in the Homoneura I imagine to be primitive 
and correlated with the fact that the group came into 
existence before the evolution of flowering plants. 
I do not doubt that other important anatomical differ- 
ences might be pointed out, but these appear to me to 
be sufficient, and this primary division of the Lepidoptera 
is, I think, generally accepted. The names Jugata and 
Frenata we owe to Comstock (p. 325). (They are some- 
times written Jugatae and Frenatae, but Lepidoptera 
Jugatae is, of course, an impossible combination.) Jugata 
is a sufficiently suitable term for the group that it represents, 
but the term Frenata is definitely misleading, as a frenulum 
is present in many Jugata, which are in fact, as Tillyard 
(A., p. 298) has shown, jugo-frenate. I therefore prefer 
to adopt the more accurate terms of Homoneura and 
TRANS. ENT. SOC. LOND. 1921.—PARTS II, IV. (JAN. 22) 
