90 BULLETIN 31, UNITED STATES NATIONAL MUSEUM. 



consisting of two large ovate spots, narrowly separated and reaching 

 the lateral margins ; second and third cross-bands broad, separated from 

 the lateral margins by a black narrow border; they are much narrower in 

 the middle of the segments, the front margin straight, touching the an- 

 terior edge of the segments; fourth baud similar, but much smaller; 

 posterior margin of the segments shining, dilated in the middle. Legs 

 brown, the posterior tibia? and all the tarsi blackish; sometimes the 

 legs are luteous, the base of femora, distal portion of tibiai, and the tarsi 

 brown. "Wings grayish hyaline, the base before the humeral cross vein 

 and the stigma brown, the remainder of tlie subcostal cell and the 

 costal cell may be brownish : third vein rather deeply curved near the 

 middle of the first posterior cell. 



Three specimens, Connecticut, Pennsylvania (S. Auxer, E, Keen). 



This species, as it has been called, shows but slight differences from 

 D. fasciata of Europe. The propriety of separating them specifically 

 is, to say the least, very doubtful. The only real difference appears to 

 be that the legs are a little lighter colored. In a single specimen that 

 I have from Holland the bands are narrower on the abdomen and the 

 brownish color of the wings fainter ; the legs are black, with the base 

 of the tibiae reddish. 



Didea lasa. (Plate IV, figs. 4, 4a.) 



Didea laxa Osten Sacken, Bull. Buff. Soc. Nat. Sci., iii, 56; Cat. Dipt., 245, 

 note 212. 



Habitat. — ISTew Hampshire, California, Washington Territory', Or- 

 egon !, Michigan, Maine (O. S.). 



5,9. Length, 10 to 13"'™. Eyes ])i]ose, more distinctly so in the 

 male. Antennae black, third joint oval, obtusely rounded on the end; 

 arista black. Face yellow, with a broad .shining black or brown stripe, 

 not reaching the antennse. Cheeks brown. Frontal triangle black, 

 yellowish dusted along the eyes, pile black; front in female shining 

 black ; on the sides the yellowish-gray dust extends up along the eyes 

 and expands in the middle, nearly meeting. Thorax blackish metallic 

 green, shining. Scutellum dull brownish yellow, with a slight greenish 

 or bluish metallic luster. Pleurae with a whitish vertical stripe. Ab- 

 domen black or bluish black, with greenish-yellow cross-bands ; on the 

 second segment two large oval spots, reaching (rarely narrowly sepa- 

 rated from) the lateral margins ; third and fourth segments each with 

 a cross band, extending narrowly quite to the lateral margins, biconvex 

 behind, and with a sharp ])OSterior notch in the middle, in some speci- 

 mens distinctly interrupted ; fourth segment behind narrowly yellow in 

 the middle, forming with the anterior angles of the fifth an entire cross- 

 band ; fifth segment behind yellow ; pile on the black portions black, 

 elsewhere yellowish. Venter black, the second, third, and fourth seg- 

 ments each with a broad cross-band, narrowed in the middle. Legs yel- 

 lowislired; i)roximalhalf of front and middle femora black, hind femora 

 black, except at tip; hind tibiae with a brown ring in the middle, some- 



