412 PROCEEDINGS OF THE NATIONAL MUSEUM. voi. xxv. 



a>)dominiil ono.s sessile, represented on joints 7 to 9 by a })unch of 

 crochets Ix'hind and a single row before each planta; on 13 a more dis- 

 tinct foot, with double row of crochets broken on the inside and out- 

 side. No feet on joint 10. Setie long, brownish, from small, distinct 

 tubercles; ia and lb in a group; ib larger; iia and iib somewhat ante- 

 riorly placed, iib large; iv and vipresent. On abdomen i and ii nearly 

 ill line, ii larg(;r; lii above and a little })ehind the small, anteriorly 

 situated sijiracle; iv below and well behind; v and vi obsolete. Su>)- 

 primary tulx^rcles all absent, apparently l)y reduction. No ventral 

 seta". Skin finely granular, shagreened, not distinctly so. 



Younger larvae were all colorless, th(» head the same but with black 

 ocelli at the edge. Anal end well rounded, the segments sut)equal 

 throughout. Seta' apparently the same. 



The cocoon is elliptical, 7. .5 by 4 mm., formed in the center of the 

 mine. Mines in the broji(l-lea\ed cottonwood in Denver. Imago 

 Julv 2. 



