86 PKOCEEDINGS OF THE NATIONAL MUSEUM vol. 68 



the host relationships and scarcely more concerning the habits of the 

 species in this genus. 



KEY TO NORTH AMERICAN SPECIES OF EUMACRONYCHIA 



1. Fourth abdominal segment wholly black 5. 



Fourth abdominal segment red, at least on its apex 2. 



2. Parafacials at most with sparse black bristly hairs on the lower half of face; 



third antennal joint bright red or yellow; claws of inner forceps of male 

 genitalia widely divergent 3. 



Parafacials on upper half, thickly beset with black bristly hairs; third joint 

 of antennae black; claws of inner forceps of male genita,lia not divergent. 



nigricornis, new species. 



3. Arista thickened on basal three-fifths; inner orbits divergent from base of 



antennae to vertex; fourth sternite of male ordinary 4. 



Arista thickened on basal two-fifths; inner frontal orbits parallel; in male the 

 fourth sternite is conspicuously exposed and covered with short erect 

 villosity, and the prongs of inner forceps are not bowed in the middle, 

 pul villi longer than the last two tarsal joints; in female, first genital segment 

 appearing like a fifth abdominal segment, not arched like an inverted V> 

 but broadly rounded above sternalis, new species. 



4. Bucca in profile equals one-half eye height; facial depression scarcely wider 



than either parafacial; in male, pulvilli longer than the last two tarsal joints, 

 prongs of inner forceps strongly bowed in middle when viewed from behind, 

 apical flexor surface of middle tibia with long, erect villosity; in female, 

 first genital segment resembles a fifth abdominal segment and is arched 



above like an inverted V decens Townsend. 



Bucca in profile equals one-fifth eye height; facial depression twice width of 

 either parafacial; in male, pulvilli shorter than last two tarsal joints, prongs 

 of inner forceps when viewed from behind are not bowed in middle; middle 

 tibia without erect villosity L montana, new species. 



5. Parafacials distinctly hairy; arista thickened on basal two-fifths; palpi and third 



antennal j oint black 6. 



Parafacials bare; arista thickened on basal three-fifths; palpi yellow. 



elita Townsend. 



6. Intermediate abdominal segments with sharply defined poUinose bands on 



basal two-thirds; buccal width less than one-third eye height. 



rohweri, new species. 



Intermediate abdominal segments densely poUinose to apices; buccal width 



exceeds one-third the eye height elongata, new species. 



EUMACRONYCHIA DECENS Townsend 



Eumacronychia decens Townsend, Trans. Amer. Ent. Soc, vol. 19, p. 99, 



1892; vol. 22, p. 74, 1895. 

 Hilarella decens Coqtjillett, U. S. Bur. Ent., Tech. Ser., No. 7, p. 128, 



1897.— Smith, Ins. of New Jersey, p. 782, 1909. 



Male. — Front at narrowest point, which is just above the base of 

 the antennae, 0.35 of head width (measurements of three as follows: 

 0.33, 0.34, 0.37) ; frontal vitta at level of lowest orbitals one and one- 

 half times width ol either parafrontal; frontal row with about ten 

 bristles; one reclinate and three proclinate orbital bristles; para- 

 f rentals with a few short bristly hairs near the vertex; facial depres- 

 sion scarcely wider than either side of face; vibrissae inserted nearly 



