AGA MR. B. F. CUMMINGS ON 
gene are drawn out ventrally into flaps, usually triangular in 
shape, which hang down as strong perpendicular walls beside 
the soft gular region (text-fig. 3, F). 
Text-figure 3. 
Phryganea, 3. 
Side view of the head (diagrammatic). Much enlarged. 
E. Eye. O. Ocellus. A. Antenna. #'. Genal flap. C. Cardo. STZ. Stipes. 
LAB. Labrum. H. Haustellum. JP. Palpus of the first maxilla. 
The cardo and stipes are not free like the four joimts of the palpus, but are 
attached by their inner surfaces to the sides of the haustellum. Maxillary lobes 
not shown. 
For the sake of convenience it is easy to divide the mouth-parts 
of adult Trichoptera roughly into those with a very elongate 
haustellum*, and with no mandibles or with the mandibles much 
reduced, and those with a shorter haustellum and a pair of 
powerful well-developed mandibles. In the former case, for 
example in Phryganea and Limnophilus, the cardo of the first 
maxilla is articulated to the head in a small angle or niche 
formed at the point where the gena curves down as the trian- 
gular flap (text-fig. 3, F). In these genera, both cardo and stipes 
are elongate and lie along each side of the stalk or peduncle of 
the haustellum and carry off the maxillary palpi at their distal 
end some distance away from the head. In the latter case, for 
* Haustellum was the name given by Lucas (19) to what he regarded as an 
enormously developed fleshy labium projecting from the head as a sort of proboscis 
by means of which caddis-flies obtain their nourishment. In reality the haustellum 
is a modification of the region of the hypopharynx. 
