1895.] The Mouth-Parts of the Lepidoptera. 549 
In Hepialus sylvinus (see fig. 1), the labium is fleshy and lip- 
like, as in pas undetermined species, but the palpi, short and 
thick, are but 1-segmented, and all that is 
left of the maxilla is a short ex-articulate 
tubercle. In H. hecta, the broad thick 
mentum bears no palpi at all, and a faint 
5 suture separates the terminal, fleshy men- 
Pie rit pr ra: tum from the narrow, fixed sub-mentum. 
tum; “4 p. labial palpus. The maxille are represented in sylvinus 
each by a short cylindrical tubercle. Thus, despite the 
obscurity which obtains in the condition of the mouth-parts of 
Hepialus because of their atrophied state, it seems apparent 
that they are reduced from a type with free lip-like labium, 
and with one or more free maxillary lobes, a generalized con- 
dition only met with elsewhere among the Lepidoptera in the 
genus Micropteryz. 
Before proceeding = a brief eee of certain struct- 
ural features of the mo mouth-parts 
as presented in the Rrenate; I wish to call attention to a few 
points of interest adduced from a comparison of the mouth- 
parts of the Jugate with those of the Trichoptera. Here, as 
elsewhere in the morphology of the Jugate and Trichopterous 
types, the comparisons are suggestive. The morphology of 
the Trichopterous mouth-parts is an interesting, and by no 
means completed, study. Latreille and Pictet found no in- 
dications of mandibles; Kolenati and Westwood found rudi- 
mentary mandibles present. Some authors have thought the 
maxilla and labium to be distinct, while Speyer and Kolbe 
declare them to be fused to form a sort of lapping or pseudo- 
sucking proboscis. Lucas’ in his recent careful study of the 
mouth-parts of Anabolia furcata pretty conclusively demon- 
strates, for this species, at least, the entire absence of mandibles 
and the distinctness of maxille and labium (see fig. 1, plate 
XXV). In the few Trichopterous forms which I have ex- 
2 Author. The classification of Lepidoptera, in Amer. Nat., V. (Mar., 1895) 
pp- 248, 1 plate. 
3 Lucas, Robert, Beiträge zur Kenntnis der Mundwerkzauge der Trichoptera, 
Berlin, 1893. (Dissertation. ) 
37 
