
376 THE AMERICAN NATURALIST. | [Vor. XXXVI. 
another Texan genus, Commoptera, the gland is situated in the 
. middle of the segment and could thus give rise independently to 
the condition of Ecitomyia or to that of Acontistoptera. The 
legs of this form are long and quite slender, the front ones are 
unfortunately broken off at the base of the femur in the only 
specimen I possess. 
Xanionotum gen. nov. 
Head broad, one and one-half times as wide as the dorsum of the thorax 
near the posterior angles; rounded triangular in shape, the anterior angles 
not at all evident, posterior ones rounded ; twice as wide as long antero- 
posteriorly, when seen from above, Eyes barely visible from above at the 
extreme posterior angles of 
N / the head. Four marginal 
N ue PA macrochatz on middle of 
Nue poa front, one on each side half- 
AQ way toward the eye, another 
24 just in front of eye, one at 
F $ posterior angle, and a pair of 
median posterior marginal 
ones and two widely sepa- 
rated discal ones. Antennæ 
rather large, of the usual 
form with apica arista, 
attached at the lower part 
of their unusually shallow 
cavities. _ Palpi visible from 
above for a distance equal to 
diameter of second antennal 
Fic. 6,—Xanionotum hystrix Q sp. nov. joint, rather slender, and with 
e usual bristles. Epistoma 
not visible from above. Ocelli absent. Eyes very small, situated slightly 
below and in front of the center of the sides of the head. Cheeks bristly, 
bearing a marginal row and an exceptionally strong macrocheta at the 
lower posterior angle. Proboscis nearly as long as height of head, acumi- 
nate, slightly geniculate at base. Thorax rounded, rather suddenly narrowed 
behind, much narrower than the head and a little longer ; slightly wider than 
long. It is very broadly rounded on the sides and at the anterior angles, 
and not at all sinuate on the sides. Dorsum so wide as to almost entirely 
conceal the pleura. Scutellum very small, without macrochætæ. Metathorax 
visible behind it as a sclerite, which is but little larger than the scutellum. 
Dorsum with a pair of strong macrochztz on the anterior angles, which are 



