ADAMS : DIPTEROLOGICAL CONTRIBUTIONS. 27 



light brown, bearing narrow brown scales, those on the ante- 

 rior part of wing intermixed with white ones ; a spot at the 

 origin of the second vein, the small cross-vein, and a spot be- 

 ginning at the base of first submarginal and crossing the 

 second submarginal and first posterior cells, clouded with 

 brown ; the cross-veins at end of first and second basal cells ap- 

 proximated ; petiole of the first submarginal cell one-half the 

 length of the cell. 



Female : Agrees with male, except has more long black 

 scales on head, petiole of first submarginal cell one-third the 

 length of that cell ; all tarsal claws simple. Length, 8 mm. 



One male and six females ; Arizona. Prof. F. H. Snow. 



CHIRONOMID^. 

 Ceratopogon dimidiatus, n. sp. 



Female : Head black, occiput and cheeks subopaque, front 

 shining, eyes widely separated, face shining, with a yellowish 

 cast, antennae dark brown, first two joints yellowish, antennal 

 hairs whitish, palpi brown, tip of last joint yellowish ; thorax 

 black, mesonotum subshining, faintly whitish pollinose, pleurae 

 with a longitudinal silvery white pollinose band, halteres light 

 yellow ; abdomen black, subshining, sparse, pile yellowish- 

 white ; coxae black, apices yellow, basal half of femora yellow, 

 apical half black, tibiae wholly black, tarsi yellow, with apices 

 of first, second, third and the last two joints wholly black, meta- 

 tarsi twice the length of the following joint, last joint of fore 

 tarsi swollen, empodia of all tarsi wanting, front tarsal claws 

 rather small but of equal length, middle and hind tarsi each 

 with a single long claw which bears a rather long basal tooth, 

 the last tarsal joints being partly padded beneath with short, 

 dense hairs ; wings hyaline, larger veins dark brown, third vein 

 connected with the first by a cross-vein, the wing in this region 

 with a brown spot ; the third vein ends at about four-fifths of 

 the distance from the tip of the first vein to apex of wing ; at 

 this point is a second brown spot ; fourth and fifth veins furcate 

 opposite the small cross-vein. Length, 3.5 mm. 



Four specimens ; Grand Canon, Arizona. 



