390 



UNITED STATES NATIONAL MUSEUM BULLETIN 2 2 4 



Abdomen : The abdomen is subcylindrical on the pos- 

 terior portion but somewhat flattened toward the base, 

 which is nearly as wide as the thorax, the whole micro- 

 punctate. The sides of the first tergite bear 5 or 6 pale 

 bristles and the second to fourth tergites each bear a 

 moderately stout, pale, lateral bristle in the middle and 

 besides also 1 long, pale, slender, subbasal hair, present 

 also on the fifth tergite. Pile of the tergites appressed, 

 scanty and black. Posterolateral margins of the ter- 

 gites densely silvery pubescent. Male terminalia small, 

 inconspicuous and almost completely hidden by the 

 cupped apex of the abdomen. The middle of the 

 curved-under, lateral margin of the sixth tergite has 

 a rather long, moderately stout, curved bristle similar 

 to those present on preceding tergites. There are six 

 long and well developed tergites; the seventh is short 

 and visible only from the rear. 



Distribution: Neotropical: Lophoceraea pennata 

 Hermann (1912). 



Genus Othoniomyia Hermann 



Figubes 249, 654, 1352, 1361, 1669, 1814 



Othoniomyia Hermann, Nova Acta Acad. Caes. Leop.-Carol., 

 vol. 96, p. 119, 1912. Type of genus: Othoniomyia triangu- 

 laris Hermann, 1912, by original designation. 



Othoniomyia has one subgenus, Sphagolestes, new 

 subgenus. 



Small, black, shining flies without punctures on tho- 

 rax or abdomen and the legs with some lighter colora- 

 tion in parts; tergites without bristles, except on the 

 first tergite. Dorsal spine of third antennal segment 

 and its incision situated at outer third of this segment, 

 but sometimes quite subapical in position. Fourth 

 posterior cell longer than the discal cell, which ends 

 in 1 vein. Ambient vein absent or nearly so. Length 

 6.5 mm. 



Head, lateral aspect : The head is of moderate length 

 and it is rather strongly convex posteriorly as well as 

 anteriorly. The face is not evident in profile, except 

 for a very low swelling situated below on the lower 

 fifth of the face. The occiput is prominent through- 

 out the middle of the head in profile but is obliterated 

 above and below. The upper half of the occiput bears 

 8 strong, sharp, rather long, black bristles. The pro- 

 boscis is small, rather short, more or less cylindrical 

 and at the most very slightly compressed; the apex is 

 obtusely truncate and bears a little pile above and 

 below. Palpus minute, cylindrical and composed of 

 two segments ; the second segment has 2 or 3 long, slen- 

 der, pale hairs at apex. Antenna elongate especially 

 on the third segment; the first segment is scarcely or 

 not quite twice as long as the short, beadlike second 

 segment. The third segment is more than twice as 

 long as the combined length of the other segments; 

 at its base dorsally it is angulate and below it is con- 

 vex and swollen a little ventrally; the apex tends 

 to turn downward and lias a short, obscure microseg- 

 ment which might be easily overlooked and which con- 



tains a blunt, central spine, very short. At the outer 

 third dorsally there is also a well developed incision 

 and spine. First segment with a long, ventral seta. 

 Head, anterior aspect: Face quite narrow and only 

 a sixth of the head width. The small ventral swelling 

 of the face bears an upper and lower pair of rather 

 widely separated, only moderately long, weak, black 

 bristles. Face surface pale, reddish brown micropub- 

 escent. The front is quite short, its sides bear 2 or 

 3 weak, short, black bristles. Vertex deeply excavated ; 

 the high ocellar protuberance has nearly vertical sides 

 and bears a pair of moderately long, but weak, black 

 bristles, divergent and curved backward. Anterior 

 eye facets in the medial area strongly enlarged. 



Thorax : The mesonotum is more than usually high 

 and convex and strongly abrupt anteriorly with dense, 

 moderately long, brownish black, suberect pile over the 

 whole. Humerus also pilose. There is a single, long, 

 slender, black notopleural bristle, 1 supraalar, 1 posta- 

 lar and 4 pairs of long, more slender scutellar bristles; 

 no prescutellar bristles. Metanotal slope with a con- 

 spicuous tuft of rather long, stiff, reddish brown pile, 

 among which are 5 weak, concolorous bristles. Meso- 

 pleuron with a single, long, weak bristle and a few 

 other hairs. The rather convex metapleuron is reddish 

 brown pollinose with a vertical band of 6 or 7 long, 

 slender, yellowish white bristly hairs curved downward 

 at apex. Pronotum with a row of weak, stiff, pale 

 hairs. Hypopleuron with 5 or 6 long, pale hairs. 

 Lateral metastemum with pile. Postmetacoxal area 

 as long as wide, a little constricted and distinctly 

 chitinized. 



Legs: The legs are rather slender and very slightly 

 thickened distally. The hind femur is moderate in 

 length with appressed, brown pile above and dorsally 

 at the apical fourth a long, slender, reddish bristle, 

 another nearer the apex but dorsomedial, and still 

 closer to the apex a weak, short, dorsolateral bristle. 

 Laterally there are 2 other quite short, weak bristles 

 on the apical third. The ventral margin bears 3 or 4 

 extremely long, very slender, white hairs on the basal 

 half and the entire ventral surface has a conspicuous 

 fringe of moderately long, yellowish, fine, erect, un- 

 modified hairs. The hind tibia has a similar fringe 

 and bears 2 long, rather slender, reddish brown, dorsal 

 bristles, 1 situated at the middle, 1 at the basal fourth ; 

 dorsally there are 5 short, fine, weak bristles. The 

 apex has weak, poorly developed bristles but the end 

 of the basitarsus has rather long bristles. Middle 

 femur with a rather long, slender, dorsal bristle on 

 the apical third, another anterior bristle on the apical 

 fourth and a few, slightly longer, stiff hairs anteriorly 

 at the apex. The brownish yellow tibia shows rather 

 long, slender bristles which are oblique and especially 

 long ventrally; there are 3 posteroventral elements at 

 basal fourth, just before the middle and a little beyond 

 the middle, with a fourth shorter one at the outer fifth. 

 Anteroventrally there are 4 or 5 shorter, finer bristles : 

 the long, anterodorsal bristles number 3 and each one 

 is matched by a shorter, posterior bristle. 



