1916.] NATURAL SCIENCES OF PHILADELPHIA. 527 
Ninth sternite almost straight across, or sUghtly narrowed to the 
truncated apex. 
Gonomyia (Gonomyia) unioolor Alexander. 
Gonoinyin anirolnr Alexander; Proceedings of the United States National 
Museum, vol. 44, p. 507, PI. 66, fig. 15 (1913). 
An extra-Hmital species (Guatemala, Central America) included 
here to complete the data. 
The male hypopygium (Plate XXX, fig. 89) with the pleurites 
moderately stout and elongated, the dorsal angle not produced; 
ventral pleural appendage (y) a double lobe, dark colored, sub- 
chitinized, the inner arm stout-cylindrical with the tip acute and 
the inner side with two or three hairs; the outer and more ventral 
arm slender, curved and bearing near the tip two stout divergent 
hairs; dorsal pleural appendage {d) a subcylindrical fleshy lobe from 
an enlarged base, at the apex with two powerful bristles; cephalic 
or inner face with four small hairs that are evenly spaced. Ninth 
tergite almost straight across or slightly concave. Penis-guard 
(Plate XXX, fig. 88) seen from beneath, a powerful, quadrangular 
chitinized base whose caudal angle is a ventrally directed hook, the 
base subtended on either side by short gonapophyses {g) that end 
in a sharp, conical spine; from above and dorsad of the quadrangular 
base arise two cylindrical, pointed, chitinized arms that are diver- 
gent. 
Gonomyia (Gonomyia) mexicana Alexander. 
Gonomyia mexicana Alexander; Canadian Entomologist, vol. 48, pp. 321, 322 
(1916). 
An extra-hmital species described from Cordoba, State of Vera 
Cruz, Mexico, May 8, 1908 (Knab). 
The male hypopygium (Plate XXX, fig. 91) with the pleurites 
elongate, though rather stout; ventral pleural appendage (v) a long, 
pale lobe, subcylindrical, blunt at the apex and bearing sparse, 
elongate hairs; second pleural appendage strongly chitinized, the tip 
acute, curved; dorsal pleural appendage {d) rather short, cyUndrical, 
fleshy, the cephalic or inner angle of the apex with two powerful 
bristles; caudal or outer angle of the apex with two smaller hairs. 
Ninth tergite rather short, the caudal margin straight or nearly so. 
Penis-guard (Plate XXX, fig. 90) very long and pale, the apex bifid 
by a deep U-shaped notch, each lobe provided with long hairs; on' 
the ventral face arises a slender, rod-like, median appendage, sparsely 
short-hairy at the apex and down the ventral face; the divergent 
subtending arms are slender, somewhat flattened, the apex produced 
