338 SUPPLEMENT. 



3. Pelastoneurus vagans. 



Pelastoneurus vagans, Loew, Neue Beitr. viii. p. 39 1 ; Mon. N. A. Dipt. ii. p. 107 2 . 

 Hab. North America, United States 12 . — Mexico, Orizaba (H. H. Smith). 

 One male. This is the most common species in the United States. 



4. Pelastoneurus argentiferus. 



Pelastoneurus argentiferus, Aldrieh, Trans. Ent. Soc. Lond. 189(3, p. 313 \ 



Hab. Mexico, Chilpancingo, Vera Cruz, Medellin, Teapa, Frontera (H. H. Smith). — 

 Antilles, St. Vincent 1 . 



Numerous specimens. 



5. Pelastoneurus hamatUS, sp. n. (Tab. VI. figg. 12, wing, 12 a, end of front 

 tarsus, d 1 .) 



<5 • Face wide, the concavity below the antennae shining green, the convexity covered with golden pollen ; 

 palpi silvery ; antennae black, first joint whitish below at the tip and with two whitish spine-like 

 prolongations — one shorter on the underside, and one longer, rather noticeable on the inner side. Front 

 green, not very shining ; cilia of lower orbit pale yellow, rather bushy. Thorax above blackish-green, 

 moderately shining ; the triangular white spot in the suture large, the black behind it not of unusual 

 size; pleurae blackish, with very thin grey dust, changing to yellowish on the upper half; halteres and 

 tegulae yellow, the latter with black hairs. Abdomen not compressed, uniform dark green in colour, the 

 sides with small white-dusted spots ; sixth segment wholly white-dusted ; hypopygium stout, black, with 

 brownish dust, not pedunculated, the lamellae short, broad, black, with quite dense hairs along the border, 

 and more delicate ones on the outer surface. Legs black, the knees and trochanters narrowly dark 

 yellow ; fore tarsus shorter than the tibia, its last four joints (fig. 12 a) of about equal length, the inner 

 claw greatly enlarged and bent back to form a grasping-organ (it bears a striking resemblance to the 

 fish-hook protruding from a trout-fly, but is stouter proportionately). Wings moderately infuscated, 

 rather narrow ; costa not thickened ; last section of fourth vein bent at its middle, thence nearly straight, 

 ending farther before the tip of the wing than in any other species of the genus known to me. 



§ . Upper part of the face dull, yellow-dusted : antennae as in the male : apical third of fore femora, and half 



of the others, dark yellow; tibiae, except the extreme base and tip, of the same colour. 

 Length 5-5'6 millim. 



Hab. Mexico, Mexico city (H. H. Smith). 



One male and two females. The arista has a shorter plumosity than in many species. 



6. Pelastoneurus bigeminatus, sp. n. (Tab. VI. tig. 13, wing of s .) 



S . Face wide, protruding below, covered with dull yellow dust, which becomes greyer along the sides below ; 

 palpi prominent ; mouth very large ; antennae small, yellow, third joint short, slightly brown at the tip ; 

 arista with very long hairs. Front opaque, covered with brownish-yellow dust. Cilia of the inferior orbit 

 white. Thorax brown, but little shining, with black dots out of which the large bristles arise ; the 

 usual black stripe above and before the root of the wing entirely divided into two ; the sutural groove 

 with yellow dust (instead of the bright white dust that is common in this genus) ; pleurae black, with grey 

 dust ; halteres and tegulae yellow, the latter with black bristles. Abdomen dull green, a little shining, 

 on the sides with patches of rather indistinct white dust ; hypopygium of medium length, more slender 

 than usual, black, the lamellae elongate, brown, the apical angle prolonged into a hairy filament. Middle 

 and hind coxae black on the basal part, the tarsi infuscated towards the tip ; legs otherwise yellow. 

 Wings moderately infuscated, with a distinct round brown spot in the apex, resting against the margin 

 before the end of the third vein, but widely separated from it behind the end of the fourth ; costa not 

 thickened ; cross-vein distant about its own length from the margin. 



