638 The American Naturalist. [July, 
being the external lobes of the underlip formed by the consolidation 
of the second pair of maxille, and which reach, when extended, 
to about the second-third of the length of the second palpal 
joint. Itsinner edge is directly connected with the inner lobe 
(mala interna). The latter are coalesced into a short, wide tube, 
which, by the greater size of the hinder wall, opens externally 
on the point, also appearing as if, at the same time, cut off ob- 
liquely from within outwards. 
“The outer anterior edge of the tube forms a strongly chi- 
tinous semi-circle which, becoming thinner, finally passes into 
the delicate membranous hinder wall. Also anteriorly a deli- 
cate membrane appears to cover the chitinous portion. | 
Fig. 1. Fic, 2. 
“ We have here, in opposition to the weak, naked under lip 
represented by a triangular chitinous plate of the Lepidoptera, 
a true ligula formed by the coalescence of the inner lobes of 
the second maxille into a tube, as in many Hymenoptera, and 
with free external lobes, which correspond to the paraglusse of 
Hymenoptera,” : 
Walter has also detected a paired structure which he regards 
as the hypopharynx. -As he states: “A portion of the inner 
surface of the tube-like ligula is covered by a furrow-like band . 
