Animals of the Mississippi Bottoms near Quincy. 159 



gallftries of agglutinated sand in which numbers live together. 

 The}^ may be found in water at all seasons of the year, even 

 under the ice in winter. Quite a number of species are repre- 

 sented by the larvee taken at Quincy, and some of the forms 

 described below may represent several related species instead 

 of one. 



The pupae differ from those of Corethra in having cottony 

 tufts or antler-shaped fleshy respiratory appendages on each 

 side of the thorax; but some apparently lack these structures. 

 Those with the cottony tufts were common in the galleries 

 under rocks. The ones with antler-shaped respiratory struc- 

 tures were taken at the surface in the bay, and may prove to 

 be free-swimming. Several of these latter had the posterior 

 part of the body enclosed in the larval skin. 



The winged adults were emerging at the surface of the bay 

 August 8. Those captured, nearly all females, were brought 

 in by the surface net, and are probably among the smallest of 

 the genus, being only about .08 inch long. Color, pale yellow, 

 with three large, brown, longitudinal spots on the thorax, the 

 middle one placed before the others and continued behind by a 

 very narrow median brown line. Segments of abdomen brown 

 centrally above; pale at the margins and below. Antennae, 

 legs, and balancers, whitish. Wings unmarked. One male 

 taken is more distinctly marked, and shows some dusky on the 

 legs and ventral side of the thorax, while the plumose antennae 

 are decidedly blackish. 



Chironomus^ larva (1). 



Large examples of this larva average about .44 inch in 

 length. Head, yellowish brown. Eye-specks, two. Labium 

 with strongly arched anterior edge, cut into about six black 

 teeth on each side, with a median tricuspid tooth. Posterior 

 segments with three pairs of fleshy (respiratory?) appendages; 

 the first pair short and club-shaped, attached at the posterior 

 edge of the antepenultimate segoient, the second and third pairs 

 long and contorted, attached the one to the middle and the 

 other to the posterior edge of the penultimate segment. The 

 four anal papillai rather slender, enlarging a trifle distally. 



