Zool.— Vol. I.] WHEELER— MARITIME DOLICHOPODIDsE. 1 49 



when these appendages are folded over the back, and the 

 additional intensity which the blotch thus acquires enables 

 one to recognize the species at a distance of a few feet. 



Aphrosylus grassator, sp. no v. 



Plate IV, Figs. 12, 13. 



Male. — Length of body 1.5 mm.; length of wing 2 mm. Antennae black, 

 third joint very short, beset with short hairs and a few black bristles, which, 

 as in the two preceding species, are more numerous on the ventral than on 

 the dorsal surface. Arista long, distinctly pubescent throughout. Palpi not 

 very much enlarged. Body opaque black throughout. Frontal bristles long 

 and prominent, as are also those on the thoracic dorsum and abdomen. 

 Bristles of the scutellum as in the preceding species. Hypopygium large, its 

 outer appendages directed forwards and bent upwards at their tips, which are 

 provided with two short, conical projections. The outer appendages are 

 fringed with very dense and coarse black hairs, especially on their mesial 

 surfaces. The inner appendages are yellowish, and the penis projects back- 

 wards and downwards between the outer appendages but not as far as in 

 A. direptor. The bristles of the abdomen end on the rudiment of the sev- 

 enth segment, which, as in the preceding species, is shifted to the left side of 

 the swollen base of the hypopygium. Legs piceous, becoming blacker on 

 the tibia; and tarsi, bristly. The bristles on the samewhat swollen fore femora 

 rather long and erect. Wings smoky, somewhat opaque, immaculate; costal 

 bristles prominent, third and fourth veins parallel, the latter ending in the tip 

 of the wing and with its proximal segment distinctly incrassated. The pos- 

 terior cross-vein is very oblique, so that it forms an obtuse angle with the 

 fourth vein. It is more than twice as long as its distance from the posterior 

 margin. Halteres piceous. Tegular cilia black. 



Female. — Length of body 2 mm. ; length of wing 2.5 mm. The face is some- 

 what broader than that of the male, the proximal segment of the fourth longi- 

 tudinal vein is not incrassated, and the bristles on the fore femora are not so 

 prominent. The hairs on the last segment of the abdomen are long and 

 prominent. The ovipostor is piceous. 



Of this, the smallest and rarest of the Californian species 

 of Afihrosylus, I have taken only three specimens, one male 

 and two females. These were captured, together with spec- 

 imens of A. frcedator, at Pacific Grove, August 5th. 

 More material is needed before it can be definitely affirmed 

 that the proximal incrassation of the fourth vein is a male 

 character and not an individual variation. 



