Vol. XI] COLE AXD LOIETT—LIST OF OREGON DIPTERA 211 



Almost all the species are aquatic in the early stages, the 

 larvae feeding on decaying vegetable substances and tiny 

 aquatic organisms. A few are terrestrial, one lives in sap and 

 one species mines the leaves of water plants. Many species 

 furnish food for trout. 



56. Chironomus colei Mall. 

 Forest Grove, VI-3 (Cole). 1919, Proc. Cal. Acad. 

 Sci., Ser. 4, IX, p. 255. 



57. Chironomus plumosus (Linn.) 

 Corvallis (Churchill). 



58. Chironomus riparius Meig. 



Forest Grove, 111-10, 20 and VI-3 (Cole); Hillsboro, 

 IV-l (Cole). 



59. Chironomus viridis Macq. 

 Forest Grove, V-17 (Cole). 



60. Tanytarsus 3 dissimilis Johann. 

 Forest Grove, VI-2 (Cole). At light. 1905, N. Y. 

 State Museum, Bull. 86, p. 292. 



61. Tanytarsus fatigans Johann. 



Forest Grove, 111-28 (Cole). 1905, N. Y. State Mu- 

 seum, Bull. 86, p. 292. 



62. Tanytarsus obediens Johann. 



Forest Grove, IV-5 (Cole) . 1905, N. Y. State Museum, 

 Bull. 86, p. 286. 



63. Tanytarsus politus Mall. 

 Forest Grove, 111-20 and VI-3 (Cole); Forest Grove, 

 V-4 (Burrill). 1915, Bull. 111. St. Lab. Nat. Hist. X, p. 493. 



64. Metriocnemis flavifrons Johann. 

 Forest Grove, 111-26 to IV-14 (Cole). 1905, N. Y. 

 State Museum, Bull. 86, p. 301. 



3A number of species were collected at Forest Grove which could not be 

 determined with certainty; some of them are probably undescribed. 



