443 



of the normal female joints, while the apical two thirds are of the 

 form usual in the male and similarly haired (PI. XXXII, Fig. 12). In 

 other respects the specimen appears to be of the ordinary female form. 

 Originally described from Washington, D. C. I have seen speci- 

 mens in the collection of the U. S. Bureau of Biological Survey from 

 Plummer's Island, Md., taken by W. L. McAtee in June and August. 



25. Chironomus riparius Meigen 



Chironomus riparius Meigen, Klass. u. Beschr. Eur. Zweifl. Ins., Vol. 1, 1804, 



p. 16, sp. 3. 

 Chironomus annularis Macquart, Recueil Soc. Agric. Lille, 1826, p. 194, sp. 2. 

 Chironomus viridipes Macquart, ibid., p. 195, sp. 4. 

 Chironomus zonulus Zetterstedt, Ins. Lappon., 1838, p. 810, sp. 1. 



Male. — Differs from fasciz'entris in having the fore tarsi bare and 

 the basal joint half as long again as the fore tibiae. 



Female. — Differs from the female of fasciventris in having the 

 basal joint of the fore tarsi comparatively longer, the proportions of 

 this joint and fore tibiae in specimens before me being 84, 54. 



Length, 6.75-7.5 mm. 



Illinois localities, Urbana, on window, April 11, 191 1 ; and White 

 Heath, in woods along bank of stream, November 22, 1913 (C. A. 

 Hart and the writer). 



I have as yet seen only females of this species and can not say what 

 is the form of the hypopygium. 



The larva, according to Van der Wulp and Weyenbergh, is trans- 

 parent and pale green, but Johannsen states that larvae from which he 

 reared specimens he identified as riparius agreed with those of dcconis 

 in all details. Some error in observation must have occurred or else 

 the European species is not the same as the American one. 



Johannsen records riparius from Ithaca, N. Y., Washington State, 

 Pennsylvania, South Dakota, Minnesota, New Jersey, and from Doug- 

 las, Alaska. 



26. Chironomus tentans Fabricius 



Chironomus tentans Fabricius, Syst. Antl., 1805, p. 38, sp. 3. 



Chironomus abdominalis Meigen, Syst. Beschr. Eur. Zweifl. Ins., Vol. 1, 1818, p. 



32, sp. 25. 

 Chironomus vernalis Meigen, Klass. Eur. Zweifl. Ins., Vol. 1, 1804, p. 13, sp. 5. 



Male. — Pale green, opaque. Head pale yellowisli green, antennae, 

 except the basal 2-3 joints of flagellum, fuscous; palpi fuscous, green- 

 ish at base. Mesonotum covered with whitish pruinescence, which is 



