118 The Philippine Journal of Science 1917 



Male and female. — Length of body, 10 millimeters in the male 

 and 11 to 12 in the female; of wing, 8 in the male and 9.5 to 10.5 

 in the female. Head black, with gray dust on the occiput; eyes 

 of the male united for a line shorter than in A. limbata; the frons 

 in the male white-dusted above the antennae and deep black on 

 fore half, in the female narrow, gray-dusted at vertex to the 

 ocelli, deep black on middle, white-dusted above the antennae. 

 Face white-dusted in both sexes, with the middle bulla more 

 developed and more prominent in the female than in the male. 

 Antennae entirely black, with long, thin black arista; palpi 

 black, white-dusted and black-haired; proboscis wholly black. 

 Hairs of the head black on frons and vertex, white on the occiput 

 and below. 



Thorax entirely black, even on the humeral calli, in the male 

 more intensively black and more shining than in female ; pleurae 

 clothed with shining gray dust and with whitish hairs ; the hairs 

 on the dorsum entirely black in the male, whitish on the hind 

 half in female; above the humeri there is inward a narrow 

 velvety black patch, more distinct in female than in male ; meta- 

 pleurae with thin and soft white hairs. Scutellum black, in the 

 male shining and black-haired, in the female gray-dusted and 

 whitish-haired. Mesophragma black, gray-dusted on the sides. 

 Halteres black, their stalks yellow at base. 



Abdomen in both sexes entirely black, shining, even on venter ; 

 the first two segments in the female gray-dusted, in both sexes 

 the two last segments with a broad triangular spot of white 

 dust on the upper side; abdominal hairs mainly whitish. Male 

 genitalia black and black-haired. Legs with the coxae black; 

 middle tibiae dark yellowish; four posterior femora with a 

 yellow ring at end, which is narrow and less distinct in the male, 

 broader in the female. 



Wings of the male with the basal half faintly yellowish hyaline, 

 the apical half infuscated, more intensively infuscated toward 

 the middle and thus forming a dark crossband below the stigma, 

 which goes below the discoidal cell, the inner angle of the second 

 submarginal being hyaline. In the female the wings are hyaline 

 on the basal half, being only yellowish along the costal cell, and 

 brown on the apical half; from the hyaline inner angle of the 

 second submarginal cell begins a hyaline band which ends in the 

 fourth posterior cell and, therefore, divides the dark part into 

 two bands, united above and below ; in the first basal cell there is 

 a dark band before the root of the third longitudinal vein. 

 Stigma brownish in both sexes. Venation as in Atherix limbata, 



