146 PROC. ENT. SOC. WASH., VOL. 24, NO. 6, JUNE, 1922 



That this actually functions as a mandible can not be doubted, 

 but no exact information is at hand regarding the nature of its 

 food; it is known however to live on the sea beach. 



In describing this unique fly as a new genus and species, I 

 am indebted to Mr. Snodgrass tor his assistance in the mor- 

 phological aspect, as well as for his drawings. His article with 

 plate follows mine. 



Melanderia, new genus. 



First antennal joint bare above, third antenna] joint short, arista dorsal. 

 Palpi large and flat, resting upon the proboscis; proboscis greatly enlarged, its 

 basal portion forming a very broad, short tube, the apical half fleshy, opening 

 underneath in a longitudinal slit, each side bilobed, the outer side pieces extend- 

 ing forward in the form of mandibles; in the type species they are elongated 

 and sharp. In the normal resting position of the mouth they are drawn up 

 enough to be mostly concealed behind the inner lobes, which extend below the 

 palpi for some distance. Head bulging behind, with numerous bristles below 

 at the neck, a single row of which extend across the occiput above with only a 

 slight interruption in the middle. Prothorax with spines around the neck 

 except below. Pleura hairy or bristly in front of the posterior spiracle, acrosti- 

 chal hairs in an irregular double row. Scutellum with a single pair of upright 

 bristles; dorsocentral bristles 6 or 7; intraalar 2, one of which is directly on the 

 .suture; supraalar 1, postalar 1. Abdomen with 6 visible segments in the male, 

 5 in the female. 



Hind cross-vein of the wing beyond the middle, about its own length from 

 the margin. Genital segments of the male rather prominent, but not extend- 

 ing forward under the venter. 



Type of genus, Melanderia mandibulata new species. 



The genus is related to Hydrophorus, differing principally in 

 the structure of the mouth. Beside the typical species i t 

 includes Hydrophorus curvipes Van Duzee. 



Melanderia mandibulata, new species. 

 [Plate 14, figs. 1-6.] 



Male. Front dark purple, face of the same color; the face runs to a sharp 

 median point below. Palpi black, with numerous long hairs; proboscis black 

 with brownish gray dust except on the mandible-like organs, which are shining, 

 black, curved and sharp, and when let down so as to be visible, have an astonish- 

 ing resemblance to the mandibles of a carnivorous beetle. The basal segment 

 of the mouth is almost as wide as the whole head and has two or three rows of 

 hairs across its apex below. Back of head with black hairs partially arranged 

 in rows, the lower hairs much the longer; antennae wholly black, very short, 

 the arista thickened at base for a very short distance, slender for the rest of its 

 length. 



Mesonotum and scutellum green, sub-opaque, with brownish dust. The 

 pleura rather pure green, but not very shining; in the side view the same color 

 extends above the suture between the humerus and the wing; propleura of 

 the same color with a tuft of coarse hairs; sternopleura on its posterior 



