SCENT ORGANS IN TRICHOPTERA. 465 
example in hyacophila, the cardo and stipes are much shorter, 
so that the maxillary palpi are carried close to the head instead 
of at a distance from it. In such cases the angle or niche 
in which the cardo, is articulated is much larger, and in this 
angle the cardo is attached to the head by the whole of its 
inner surface, whereas in Phryganea and others this angle or 
Text-figure 4. 
LAB 
Sericostomea personatum. 
Head from in front with the palpi and lobes of the first maxillee dissected off 
(diagrammatic). >< 36. 
E. Eye. Aj. First segment of the antenna, excavated to receive tips of the 
palpi. P. Upturned process. LAB. Labrum. SC. Soft chitin. C.SC. 
Cly peal sclerite. 
niche receives only the proximal end of the cardo, which is 
provided with a stout condyle for the attachment of a powerful 
muscle arising from the tentorium. ‘The stipes is carried at 
right angles to the cardo, so that the general direction of the 
palpi is dorsal. The female of Sericostoma personatum agrees 
