JIEMOIES OF THE NATIOI^AL ACADEMY OF SCIENCES. 
59 
The outer exterior ed^e of the tube forms a strongly chitiiious semicircle •which, becoming thinner, finally passes 
into the delicate membranous hinder wall. Also anteriorly a delicate membrane appears to cover tlie chitinous 
portion. 
"We have here in opposition to the weak naked uuderlip represented by a triangular chitinous plate in other 
Lepidoptcra a true ligula formed by the coalescence of the inner lobes of the second maxilla* into a tube, as in 
many Hymeuoptera, and with free external lobes which correspond to the paraglossiu of Hymenoptera. 
Walter has also detected a paired structure which he regards as the hypopharyux. As he 
states: 
A portion of the inner surface of the tube-like ligula is covered by a furrow-like baud which, close to the 
inner side, is coalesced with it, and in position, shape, as well as its appendages or teeth on the edge, may he 
regarded as nothing else than the hypopharyux. 
While he refers to Burgess’s discovery of a hypopharyux in Banais arcliiiypusy he remarks that 
this organ in the lower Micropteryginm (Eriocephalidie) exhibits a great similarity to the relations 
observable in the lower insects, adding: 
The furrow is here williiu coalesced with the inner side of the labium, and though I see in the entire structure 
of the head the inner edge of the ligula tube extended under the epipharynx as far as 
the inandihle, I must also accept the fact that here also the hypopharyux extends to the 
.mouth-opening as in all other sucking insects with a well-developed underlip, viz, the 
Diiitera and Hymeuoptera. 
Another feature of importance diagnostic of tbi.s suborder is the 
maiulil)les (fig. 3), whicli, in form, size, and the presence of teeth, are 
closely related to those of the lower mandibulate orders, being, as Walter 
states, in the form of true gnawing jaws, like those of the biting insects. 
They possess loowerful chitinous teeth on the opposed cutting edge, twelve 
to fifteen on each mandible, and also the typical articulating hook-like 
processes by which they are joined to the gena, and fit in corresponding 
cavities in the latter. In Micropteryx and other of the more generalized 
moths the mandibles in a very reduced form have survived as functiouless 
vestiges of the condition in Eriocephala. 
Turning now to the head and trunk, we find other p)riuiitive characters 
■correlated with those just mentioned. 
The head is of moderate size, as well as the body, with small compound 
eyes, and with two ocelli. The occipital region is well developed, as is the 
■epicranium: the clypeus and labrum are of moderate size. 
1 he generalized nature of the thorax is especially noteworthy. The outer articulation; cavity of 
prothorax is seen to be Very much reduced, the two tergites being separate the joint (acetabulum); a, end 
and minute, not readily seen from above. The rest of the thorax is very edgl-Afte^w^ten^ 'Utnng 
long, exhibiting but little concentration. 
The mesothorax is but slightly larger than the metathorax. The mesoscutum is very short; 
the scutellum rather triangular than scutellate. 
The metathoi'ax is but little shorter and smaller than the mesothorax and remarkable for the 
widely separated halves of the scutum, a neuropterous character (compare Ascalaphus and 
Corydalus), in which it differs from Micropteryx. The shape of the scutellum is that of a low 
flattened triangle. 
As regards the abdomen, attention should be called to the disparity in size and shape between 
the sexes; also to the male genital armature, which is very large and completely exserted, 
and reminds us of that of Corydalus, iii which, however, the lateral claspers are much reduced; 
and also of that of certain Trichoptera (Sericostoma, Tinodes, Steuophylax, Hydropsyche, etc,), 
'The venation of both pairs of wings is much as in Micropteryx. 
The larval characters of this suborder it would be difficult to give, for in the remarkable larva 
of Eriocephala calthella, as described and figured in Dr, Chapman’s elaborate account, we appear to 
have a highly modified form, entirely unlike the simple apodous larva of Micropteryx and i)erhaps 
quite unlike the primitive stem-forms of lepidopterous larvm. Chapman well represents its form, as 
>we can testify from mounted specimens in a slide kindly given us by him. The body is broad 
