674 Mr. J. R. Mallocli on Exotic Muscaridae. 



from another species which I have before me, and, believing 

 as I do that either a difference in a structure of more 

 fundamental importance than the wing, or the existence of 

 several characters in common distinguishing the species of a 

 group from their allies are essential to relegate the forms to 

 distinct generic status, I cannot reasonably debar this new 

 form from Ecesid, though the habitus of the two species is 

 entirely different. It is also pertinent to state that I have 

 seen only the male of singularis ; the female may have 

 more normal wings. I would therefore amend the generic 

 description by eliminating reference to the shape of the 

 wings. 



Exsul tenuis J sp. n. 

 Male. — Black, densely opaque pale grey pruinescent. 

 Head whitish pruinescent, the parafacials almost silvery, 

 parts showing blackish in some lights. Dorsum of thorax 

 with two narrow black vittse in front of suture between 

 the dorso-centrals, and a broader one on each side be- 

 yond the dorso-centrals, all of which are continued beyond 

 suture but not to hind margin, and a brown central vitta 

 posteriorly ; scutellum with a blackish spot on each side at 

 base; mesopleura with a faint brown spot on upper hind 

 margin. Abdomen with a pair of subtriangular brown spots 

 near hind margin of the first three tergites. Legs black. 

 Wings whitish, with a brown suffusion along sides of all 

 longitudinal and cross veins. Calyptrse white. Knobs of 

 halteres brown. 



Eyes hairy ; frons much w^idened anteriorly, at narrowest 

 part, in front of anterior ocellus, fully twice as wide as third 

 antennal segment ; orbits with bristles to above middle, and 

 fine hairs above and laterad of them ; parafacials haired on 

 upper half ; antennae half as long as face, third segment 1*5 

 as long as second; arista almost bare, second segment thick, 

 slightly longer than wide, third much thickened at base, 

 rapidly tapered ; facial ridges setulose on lower half ; para- 

 facials about 1*5 as wide as third antennal segment, and 

 half as wide as height of cheek ; palpi slightly dilated 

 apically, bristly ; proboscis thick and glossy, with very 

 strong apical teeth. Thorax with four pairs of postsutural 

 dorso-centrals; both intra-alars strong; presutural acrostichal 

 hairs sparse; sterno-pleurals 1:1; hypopleura bare. Abdo- 

 men cylindrical, very slender, about twice as long as thorax, 

 with sparse long setulose hairs; basal sternite bare; seventh 

 tergite cleft longitudinally in centre, with long setulose hairs 

 on sides of cleft ; fifth sternite with a deep V-shaped notch. 



