438 



i8. Chironomus utahensis, n. sp. 



Male. — Black, slightly shining. Head entirely black, antennal 

 plumes fuscous. Mesonotum with the spaces between the vittae cov- 

 ered with grayish pruinescence ; pleurae and scutellum gray pruines- 

 cent. Abdomen with very slight pruinescence on the posterior mar- 

 gins of segments. Legs black, tibi?e and bases of tarsi brownish. 

 Wings clear, first and third veins blackish brown, cross vein slightly 

 infuscated, the other veins indistinct. Halteres black, the knobs yel- 

 low. 



Frontal tubercles distinct; antepenultimate palpal joint longer than 

 penultimate, the latter and the ultimate subequal. Pronotum distinct 

 but not broad. Hypopygium as in Figure 6, Plate XXXVIII. Fore 

 tarsi with long hairs, basal joint very little longer than fore tibise 

 (83 : 75) ; mid and hind legs with long hairs. Venation as in inahirus. 



Length, 7-8 mm. 



Type locality, Kaysville, Utah, April 7, 19 12 (E. R. Kaimbach). 



This species is probably that which was considered as niveipennis 

 by Johannsen. The latter species was recorded from Florida by John- 

 son, but the specimen upon which the record is based is a female of 

 C. lohiferus, which I have before me. 



The type specimen of utahensis is in the collection of the U. S. 

 Bureau of Biological Survey. 



Niveipennis Fabricius, or at least an Austrian specimen named as 

 such, submitted by Professor Johannsen, has the extension of the 

 dorsal plate of the hypopygium much longer than in utahensis and the 

 whole hypopygium more slender. 



19. Chironomus i'asciventris, n. sp. 



Male. — Black, slightly shining. Head brown, face yellowish; an- 

 tennae black, extreme base of flagellum brownish, the plumes brown. 

 Thorax with yellowish gray pruinescence, the vittse less densely cov- 

 ered than the remainder of disc, anterior lateral angles of mesonotum 

 and scutellum sometimes yellowish. Abdomen with the apical third of 

 segments 1-5 pale yellow, the remaining segments with less distinct 

 yellowish marks on lateral apical angles. Legs brownish yellow, 

 apices of femora, bases and apices of tibiae, the apices of basal two 

 tarsal joints and the apical three slightly darkened. Wings clear, veins 

 yellowish, cross vein distinctly infuscated. Hairs on body and legs 

 yellow. Halteres yellow. 



Frontal tubercles distinct; antepenultimate joint of palpi slightly 

 the longest. Pronotum moderately broad throughout its entire length. 



