62 DIPTERA OF NORTH AMERICA. [PART II. 



the inferior orbit yellow. Lamellae of the hypopygium rather 

 small, ovate, whitish, with a narrow black border, jagged at the 

 tip and with black bristles round the edge. Fore coxas saturate 

 dark yellow, with black hairs ; the four posterior coxa? blackish 

 with a dark yellow tip ; the rather stout feet also dark yellow ; 

 hind femora with a bristle before the tip ; the middle tibias have 

 at the tip, on the upper side, a whitish, distinctly swollen spot, 

 which is bare of any hairs or bristles ; upper side of the hind tibiae 

 with numerous bristles ; there is no glabrous spot on their hind 

 side. Tarsi plain ; the four anterior ones are blackened from 

 the tip of the first joint ; the base of the second, sometimes also of 

 the third joint, remain however pale ; the hind tarsi are altogether 

 black. Cilia of the tegulse black. Wings grayish-hyaline, with 

 a wide sinus on the hind margin, before the anal angle ; costa 

 hardly thickened near the tip of the first longitudinal vein ; the 

 last portion of the fourth longitudinal vein considerably inflected 

 about the middle, without being broken. 



Hob. Illinois. (Le Baron.) White Mountains, N. H. (Osten- 

 Sacken.) 



31. I>. sexarticulatlis, n. sp. . Aureo-viridis, nitidus, anten- 

 nis rufis, ciliis ooulorum inferioribus flavicantibus, ciliis tegularum 

 nigris, coxis omnibus pedibusque flavis, tarsis posterioribus iride ab 

 articuli primi apice ex fusco nigris, alarum vena longitudinal! quarts, 

 non fracta. 



. Hypopygii apice flavo, lamellis albis late nigro-limbatis, tarsorum an- 

 ticorum articulis tribus primis elougatis, flavis, articulis ultiinis duobus 

 brevibus compressis, paenultimo toto atro, ultimo in basi atro, in apice 

 niveo et appendicula lamellifornii, cum articulo ipso concolore, instructo. 



9 



Gold-green, shining ; antennae red, cilia of the inferior orbit yellowish, on 

 the tegulas black; all coxae and feet yellow, the middle and hind tarsi 

 from the tip of the first joint brownish-black ; the fourth longitudinal 

 vein not broken. 



$ . Tip of the hypopygium yellow, lamellae white with a broad black 

 border ; the three first joints of the fore tarsi elongated, yellow, the two 

 last ones short and broadly flattened ; the penultimate entirely black ; 

 the 'last one black at the basis, snow-white at the tip, provided with a 

 lamelliforrn appendage of the same color with this joint. 



9 Long. corp. 0.22. Long. al. 0.22. 



Golden-green, rather shining, still the thorax rather distinctly 

 dusted with ochre-yellow ; front steel-blue ; scutellum greenish- 



