212 PAPERS BY DR. B. CLEMENS. 



tennse one-third less long than the fore-wings. Labial palpi 

 slender, ascending, not higher than the vertex; the second 

 joint is scaly, the third smooth. Beneath the labial palpi are 

 small, ascending maxillary palpi. Tongue naked, as long as 

 the fore coxae and femora. 



The larva is much flattened, and the segments separated 

 by deep incisions, particularly on the sides. The head is 

 extremely thin, circular, with a peculiar appendage in front 

 of the mandibles similar to that found in the larva of Litho- 

 colletis of the second group* which it likewise resembles in 

 form. Like these it has three feet and three abdominal pro- 

 legs and one terminal pair, all very short. It leaves its mine 

 at maturity to weave a white, semi-transparent cocoon within 

 some crevice of the bark of the tree on which it feeds or upon 

 the ground. The exterior of the cocoon is covered with little 

 froth-like globules, which resemble minute pearls. 



The imago rests with the front part of the body elevated, 

 and, I believe, the fore-feet applied to the breast, like the 

 members of the genus Tischeria. The antennas are held 

 extended at the side of the head, and have a constant trembling 

 motion. 



M. salictella. Fore-wings dark fuscous, with a silvery- 

 white band at the basal third of the wing, and a slightly 

 oblique one of the same hue, in the middle inclined towards 

 'the inner angle. Near the tip of the wing is a dorsal and 

 costal silvery-white spot opposite each other. Behind the 

 dorsal spot, is a narrow, somewhat curved white streak, 

 extending from the apical cilia to the middle of the wing. 

 Cilia silvery-grayish at the tips. Hind- wings grayish- 

 fuscous. 



Antennas grayish-fuscous. Head silvery-white. Labial 

 palpi silvery ; the hairs of the second joint touched with fus- 

 cous. Maxillary palpi dark fuscous. 



The larva mines the young branches of the yellow willow 

 tree. I have always found it in those that spring from the 



* See ante, p. 63. H. T. S. 



