Claassen: Larva of a Chironomid. 397 



tion of this species will be given by Doctor Needham in a paper 

 which is soon to be published. 



The chironomid is a new species of Trissocladius, a genus new to 

 this country.* 



DESCRIPTION OF THE STAGES OF THE CHIRONOMID. 



Trissocladius equitans n. sp. 



ADULT. 



Length, 4.5 mm., exclusive of antennae. General color, blackish brown. 



Head blackish ; ej-es black, naked, slightly emarginate on inner margins, the 

 facets moderately rounded; distance between the eyes from above greater 

 llian the length of the eye. Labium short, thick, and reaching to the second 

 segment of the palpi. Palpi short, three-segmented; the first segment nearly 

 twice as long as broad; second segment twice as long as broad; third seg- 

 ment graduallj' tapering to the tip and a little longer than second segment; 

 total length of palpi about .25 mm. Antennae composed of fourteen segments, 

 the terminal one-half again as long as the combined length of segments two 

 to twelve; ba^al segment large; second segment about twice as long as third; 

 total length of antenna L3 mm.; entire antennae covered with long hairs, the 

 basal hairs as long as the terminal segment. Epistome without bristles; trans- 

 verse suture distinct. 



Thorax blackish brown, with whitish pruinose patches; dorsum with a 

 naiTow median line, depressed in front and raised into a feeble carina behind 

 the middle; surface smooth except for a few hairs on each side of the broad, 

 flattened longitudinal area of the mesonotum ; collar incised in middle, angles 

 rounded; scutellum and metanotum blackish, smooth; plura and pectus black- 

 ish, smooth. 



Abdomen compressed, blackish, with long, yellowish hairs ; basal segment of 

 the male clasper about twice as long as the distal segment, spoon-shaped, 

 the median projection or tubercle blunt, with short hairs, basal segment below 

 with long hail's; distal segment narrow at base and gradually enlarging toward 

 the apex, a few hairs above and underneath with two short spines near 

 the tip. 



Wings milkj^ white, reaching to the base of the claspers; surface finely 

 punctate; anal lobe produced and fringed with long hairs; venation as in 

 figure 14. 



Halteres pale, slightly infuscated. 



Legs light brown, hairy; tibia of front leg L4 times the length of metatarsus; 

 a single distinct spur at distal end of tibis. the ones on the posterior legs 

 being much larger; fourth and fifth tarsal segments of equal length; tarsal 

 claws squarely truncate, surface fluted; no pectinate empodium present. 



Type in the Cornell University collection, now mounted in balsam. Para- 

 types, two males; one a pinned specimen, the other in alcohol, in the Cornell 

 University collection. 



These specimens are all from Estes Park, Colo., August 7, 1921. 



♦Acknowledgments are due to Dr. O. A. Johannsen, who recognized this as a new species, 

 and without whose assistance the following descriptions could not have been adequately made. 



