282 NEW YORK STATE MUSEUM 



and the humeri yellowish. Albdomen blackish or brownish, venter 

 sometimes yellowish. Wings darker than those of the male, the 

 anterior veins dark, K 4+5 slightly bowed toward the costa beyond 

 its middle. In other respects like the male. Length, male and 

 female, 2.5 to 3 mm. 



In immature specimens the legs and particularly the femora 

 are pale. The paler female specimens resemble pubitarsis ; 

 the male differs in having no pale margins on the posterior ab- 

 dominal segments. 



Numerous specimens, Ithaca N. Y. Douglass, Alaska. 



18. Orthocladius basalis iStaeger 



1845 Chironomus Staeger. Krojer: Naturh. Tids. n. s. 1:351,6 

 1872 Chironomus Holingr. Ofv. K. Vet. Akad. Forh. 29 : 105 

 1878 Chiron omus Ost. Sack. Cat'l. Dipt. N. A. p.20. 

 1898 Chironomus Lundb. Vidensk. Meddel. p.279, 60 

 1902 Orthocladius Kertesz. Cat'l. Dipt 1:216 

 1869 Chironomus pavidus Holmgr. K. Svensk. Vet. Akad. Handl. 

 8:5, 42 



The following is Holmgren's description of pavidus: 

 Male. Antennae a little shorter than the thorax, with fuscous 

 black hairs ; the joints somewhat separated. Thorax smooth and 

 wholly shining, excepting the scutellum and metanotum; meso- 

 thorax with three stripes, the middle one produced anteriorly, and 

 depressed posteriorly in front of the scutellum, with three short 

 projecting points; scutellum obtuse, elevated and pilose. Ab- 

 domen blaick, subopaque, pale haired, the first segment wholly, the 

 posterior margins of the others shining. Wings narrow, cinereous 

 white or slightly smoky, darker along the costa; crossvein 

 straight; subcosta slightly curved, extending to about the middle 

 of the' wing, with two distinctly spurious veins (folds?) ; fork of 

 the cubitus but little distad of the crossvein. Halteres white or 

 yellowish. Legs black fuscous, the middle of tibiae or before the 

 base very frequently paler; the middle and hind legs sparsely 

 haired; the fore tibiae and tarsi very short haired; fore meta- 

 tarsus about one third shorter than the tibia. Length 3 mm. 



Staeger's description of basalis is as follows : 

 Female. Head black, front shining. Thorax with humeri and 

 pleura in front of base of wings yellowish, the dorsuim with three 

 confluent black stripes; the sternum grayish black. The coxae 

 shining black. Abdomen velvet black, the first two segments 

 yellowish brown (in fresh specimens perhaps pure yellow), and 

 the posterior margins of the following segments shining black. 

 The wings are somewhat darkened; the anterior veins and the 

 crossveins are dark brown and prominent, the other veins are 



