184 DIPTEROUS GENUS DIAPHORUS 



die tarsi longer than their tibiae, the first joint being about as 

 long as the three following together ; hind tarsi much shorter 

 than their tibiae. Tegulae, their cilia and the halters pale yel- 

 low. Wings grayish hyaline ; the first vein reaching about one- 

 third of the distance to the tip of the second vein; third vein 

 bent backwards towards the tip somewhat as in D.' simplex Aid. 

 (Fig. 14) ; veins brown, yellow at the root of the wing. 



Described from two males from California, one labeled 

 "Claremont, Cak, Baker ;" the other "Three Rivers, Calif., 

 Clbrtson," both from the Aldrich collection, and presented to 

 him by Prof. C. Fuller Baker. Type in the collection of Prof. 

 J. M. Aldrich. 



26 Diaphorus usitatus n. sp. 



Male : Length 2.1 mm. Face wide with the sides parallel, 

 covered with silvery pollen ; palpi rather large, as long as the 

 proboscis, yellowish white, brownish at base ; front metallic 

 green with very thin white pollen, a little wider than the face; 

 antennae black, third joint a little shorter than the first, slightly 

 pointed at tip (Fig. 4); arista inserted just above this point; 

 cilia of the lateral and inferior orbits white ; the hairs on the 

 lower part of the orbits rather long and abundant. Thorax 

 and scutellum metallic green with golden reflections and consid- 

 erable white pollen on the dorsum ; pleurae dulled with white 

 pollen. Abdomen metallic green with a little white pollen along 

 the sides and rather long white hairs on the venter and lower 

 part of the sides, bristles at tip very short but stout as if broken 

 off; hypopygium small, concealed, with a long stout, dark brown 

 filament inserted at base below and directed forward, nearly as 

 long as the diameter of the hypopygium (this may not be found in 

 all specimens.) Coxae black the fore pair slightly greenish, 

 tipped with yellow, with white hairs on the front surface ; mid- 

 dle pair with a few white hairs ; hind pair with the usual black 

 bristle on the outside ; fore trochanters yellow ; femora metallic 

 green with yellow tips ; tibiae and base of tarsi yellow still the 

 tibiae slightly brownish at tip ; hind tarsi brown almost from the 

 base ; fore and middle tarsi becoming brownish from the tip 

 of the first joint ; middle tibiae with the usual bristle near the 

 knee rather large ; bristles of the hind tibiae small ; hind femora 

 with a few bristle-like hairs close to the tip on the outside ; pul- 



