HYDRELLINA. 151 



side of the thorax dusted with brown ; its anterior border, shoul- 

 ders, lateral border and pi euros grayish-white with white dust. 

 Scutellum like the upper side of the thorax, only a little more 

 glossy. Abdomen almost blackish-brown, not very shining, but 

 also little dusted. Legs brownish-black; fore coxas yellow, some- 

 what infuscated at the base ; all the knees brownish-yellow ; end 

 of the foremost tibia? for a little distance and the end of the mid- 

 dle and hindmost as far as the middle, reddish-yellow; fore tarsi 

 only at the base, middle tarsi as far as the middle, the hind tarsi 

 as far as the end of the fourth joint, reddish-yellow. Poisers 

 yellow. Wings a little grayish ; second segment of the costal vein 

 nearly half as long again as the third. Hydrell. ischiaca is rather 

 similar to the European species : fulviceps Stenh., pilitarsis Stenh., 

 and laticeps Stenh. ; from the first it is sufficiently distinguished 

 by its broader face being dusted with whitish ; from pilitarsis like- 

 wise by its broader and whitish-dusted face, and moreover by the 

 pure white color of the frontal dot, the much whiter dust on the 

 shoulders, anterior and lateral borders of the thorax and pleura?, 

 and finally by the much more extensive pale color of the legs ; 

 from laticeps by the rather less breadth of the front and face, by 

 the wings showing no whitish appearance in any direction, and by 

 the less extensive pale color of the legs. 

 Hob. Middle States. (Osten-Sacken.) 



2. H. hypoleuca LOEW. 9 Subsenescenti-fusca, antennis nigris, 

 facie punctoque frontal! candidis, thoracis margine antico et margine 

 lateral!, pleuris ventreque albo-pollinosis, pedibus nigris, metatarsis 

 posticis rufis. 



Somewhat brassy-brown, antennae black, face and frontal dot pure white ; 

 anterior and lateral borders of the thorax, pleurae, and the whole under 

 side of the abdomen dusted with white ; legs black, first joint of the 

 hind tarsi red. Long. corp. 0.11. Long. al. 0.12. 



Very similar to the European H. incana Hal., which Mr. 

 Halrday thinks to be the same as H. ranunculi, previously de- 

 scribed by him. Face snowy white, not very narrow, underneath 

 broader, slightly keeled in its whole length, beset on each side 

 with three small bristles. Palpi yellow. Cheeks descending but 

 little below the eyes. Antennae black; antennal bristle in the 

 described specimen with five rays. Front dusted with brown, 

 opaque ; anterior border, but especially the shoulder and lateral 



