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UNITED STATES NATIONAL MUSEUM BULLETIN 224 



a large circular pit containing almost a completely con- 

 cealed short spine. While there are indications of a 

 microsegment, there seems to be a complete fusion of 

 any such microsegment except for incomplete, dorsal, 

 circular, liplike fissure. First segment with 5 or 6 

 short, bristly setae, appressed dorsally and vent rally, 

 second segment with a somewhat greater number of 

 longer setae above and below, 2 of the ventral elements 

 being especially stout but not quite as long as the seg- 

 ment to which they are attached. Third segment dor- 

 sally at the base with 6 especially stout, rather long 

 bristles. 



Head, anterior aspect : The face below the antenna is 

 slightly more than one-third of the width of the head 

 and is divergent below. Subepistomal area is large and 

 extensive, shallowly convex and only slightly oblique. 

 Face densely pollinose and apilose, with a prominent 

 row of stout, close-set, supraepistomal bristles of 6 or 7 

 pairs. Front short, pollinose, very slightly wider than 

 the upper face with 9 or 10 extremely short, erect, micro- 

 setae on the upper front; eye margins extending on to 

 the vertex. Vertex but little excavated, the ocellarium 

 large, but low, bearing 1 pair of short, stout bristles. 

 Anterior eye facets scarcely enlarged. 



Thorax : The thorax is pollinose, the mesonotal length 

 is 3 times the height, gently sloping on the posterior 

 half, abruptly sloping anteriorly. Pile of mesonotum 

 very scanty, consisting of short microsetae; there is an 

 acrostical row of minute setae followed by a wide, bare 

 space; the dorsocentral microsetae are not or are 

 poorly differentiated anteriorly but behind the humerus 

 they become the only pile laterally, except near the 

 lateral margins where from humeri to suture there are 

 25 short setae. Humerus with 7 or 8 microsetae. The 

 following complement of medium length, stout bristles 

 is present in the type of genus: 2 humeral, 3 or 4 

 notopleural in an oblique row, 3 or 4 supraalar, 2 post- 

 alar, and no scutellar bristles. The scutellum is rather 

 short, quite flat except for the thickened rim, which 

 is convex. The basal crease is distinct, a little deeper 

 laterally ; scutellum apilose with some scant, dark pol- 

 len. Propleuron ventrally and dorsally with numerous, 

 fine, rather stiff hairs; the dorsal collar with 7 or 8 

 pairs of slender bristles; middle posterior part with a 

 single, stout bristle. Pleuron pollinose but almost api- 

 lose; mesopleuron without pile; sternopleuron with 5 

 appressed microsetae posterodorsally ; metapleuron 

 with at least 6 long, stout bristles. Metanotal slopes 

 pollinose only ; tegulae with setae ; lateral metasternum 

 posteriorly with a number of stiff, bristly hairs; ventral 

 metasternum chitinized, apilose; postmetacoxal area 

 membranous. 



Legs: All the femora are slender, the hind femur 

 and its tibia distinctly elongate. The anterior and 

 middle femora approximately the same length ; all the 

 femora with abundant, quite short, appressed micro- 

 setae. In the type of genus the hind femur has 5 or 

 6 short, lateral bristles, the last one near the middle 



and with 4 ventral bristles distributed over the middle 

 third ; the apex on the dorsal half without any bristle. 

 Hind tibia with short, stout bristles, 4 dorsomedial, 5 

 dorsolateral, 3 weak, short ventromedial basally, 7 

 longer ventral bristles, the last 2 or 3 of greater length 

 and with a third bristle ventrally between the others ; 

 apex with a dorsolateral, a lateral, a medial and 6 ven- 

 tral bristles. A setae brush is present medially on the 

 outer half but ventrally only at the apex. Middle 

 femur with a stout posterodorsal, apical bristle and 3 

 or 4 short, anteroventral bristles; these tibia have 8 

 anteroventral, 5 anterodorsal, 2 on the outer half much 

 longer and stouter, besides 4 short, posterodorsal and 

 7 or 8 short, posteroventral, and 2 long, stout, distal 

 ventral bristles. Anterior femur with 3 short antero- 

 ventral bristles, its tibia with 4 short anterodorsal, near 

 the apex anteriorly with 2 long, stout bristles; also 5 

 short, posterodorsal, 8 short posteroventral and on the 

 outer fourth a single, long, stout ventral bristle. Ven- 

 tromedially is a protuberance bearing a stout laterally 

 curved spine. All basitarsi are rather long, as long as 

 the next three segments ; the anterior basitarsus with a 

 denticulate wheellike, basal flange. All tarsi end in 

 stout sharp claws, arched from the base, a long bladelike 

 unswollen empodium, and reduced pulvilli half as long 

 as the claws. 



Wings : The marginal cell is open by only its max- 

 imum width. Submarginal cell open for a like distance. 

 Anterior branch of third vein gently sinuous or sig- 

 moid, ending distinctly before the apex of the whig and 

 slightly arched anterobasally taking origin opposite 

 the end of the discal cell; the posterior branch ends 

 far behind the apex. First posterior cell is widely 

 open but slightly narrowed ; fourth posterior cell closed 

 with a long stalk, gently convex anteriorly and pos- 

 teriorly, its end vein and the lower end vein of the 

 discal cell, though neither are quite straight, are almost 

 completely aligned; middle end vein of the second 

 basal cell is short; anterior crossvein enters the discal 

 cell in the middle. Anal cell closed in the margin; 

 alula large; ambient vein complete. 



Abdomen: The abdomen is a little longer than the 

 wing, cylindrical, the first tergite wider than the meso- 

 notum, but not wider than the thorax, the remainder 

 of the abdomen gently tapered from the base of the 

 second tergite. Male with eight tergites, the eighth 

 one-sixth as long as the seventh; female with eight 

 tergites, the eighth one-half as long as the seventh. 

 Pile of abdomen quite scanty, extremely short micro- 

 set ate, but more abundant on the terminal segments, 

 though equally short. First tergite with some slightly 

 longer bristly pile and 4 to 7 pairs of short, stout 

 bristles. First sternite apilose, remaining sternites with 

 scanty microscopically short hairs. Male terminalia 

 rather short, rotate one- fourth, the epandrium cleft to 

 the base and divergent on the distal half. Hypandrium 

 only half as long as epandrium and gonopod well de- 

 veloped. Female terminalia with 5 pairs of slender, 

 blunt, attenuate spines with dorsal grooves. 



