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UNITED STATES NATIONAL JMUSEUM BULLETIN 224 



longer. Sides of first and second tergite with some 

 scattered, long hairs. First tergite laterally with 4 or 5 

 long, stout bristles ; the second tergite posteriorly and 

 laterally but set quite far from the apical margin has 

 4 stout, prominent bristles, and the third to fifth ter- 

 gites similarly each have 3; remainmg tergites with 

 weaker bristles. Males with 8 tergites, the eighth being 

 a fourth as long as the seventh but of uniform length 

 throughout. Male terminalia unusually large and 

 broad, a little longer than wide; the superior forceps 

 exceptionally wide from dorsal aspect, notched apically 

 and separated from the promment but short gonopod 

 by a wide gap. The hj'pandrium is short but remark- 

 ably wide, extending around the sides laterally. Ven- 

 tral surface widely open with exceptionally stout, 

 curved laminate aedeagus and penis guides, divided 

 apically and curved upward. 



Distribution : Neotropical : Cnodalomyia obtusa, new 

 species. 



Cnodalomyia obtusa, new species 



Length 18 mm. Male. Head: The head is black in 

 ground color, face densely, pale, brownish yellow micro- 

 pubescent and of a darker color on the dorsal half ; that 

 portion on the eye margin linearly is paler and sepa- 

 rated by a crease. Whole cheeks with similar pubes- 

 cence, slightly darker. Front with pale, brownish 

 yellow pollen, more scanty in the middle and also ex- 

 tended over the low ocellarium. The deep pocket of the 

 postvertex has pale pollen and the whole occiput like- 

 wise. There appears to be a large, round, black spot 

 on the upper occiput wanting in poUen, which becomes 

 visible in a different light. Upper half of face without 

 pile. Gibbosity extremely low, the face almost plane 

 in profile. There are 2 pairs of stout, rather long, black 

 bristles set medially at the middle of the face on the 

 upper border of the low gibbosity and lying outside 

 these are 6 or 7 much shorter, slender, black bristles. 

 Still lower in the middle of the face is a vertical cluster 

 of 6 to 8 much stouter, quite long, yellowish wliite bris- 

 tles which sometimes include 1 or 2 black elements. 

 Also on the lateral sides of the long, subepistoma are 

 several pale, stout bristles, among which may be in- 

 cluded 1 or 2 black elements. Pile of the occiput me- 

 dially long and scattered and fine with at the bottom 

 of the eye a tuft of long, bristly, yellow pile. Bristles 

 begin at the middle of the occiput above and consist of 

 about 12 pairs, the lower elements turned downward, 

 the upper elements rather stout. 



Anteima with the first two segments light orange- 

 brown, the extreme base of the third segment similarly 

 colored, the remainder of the long third segment dark, 

 reddish brown. The third segment has a very short 

 microsegment, followed by a thick, blackish style no 

 longer than the third segment. Sides of front with a 

 partly doubled row along the eye margin, containing 9 

 bristles, at least 3 of which are long and stout. The 

 low ocellar tubercle contains 3 pairs of quite short, an- 

 teriorly directed black bristles. Proboscis black, the 

 palpus small and black with yellow hairs. 



Thorax: The mesonotum is quite opaque black for 

 the most part, and with a very wide, medial stripe, 

 which is rounded anteriorly; it begins at the anterior 

 margin and reaches the scutellum, but is attenuate and 

 narrowed. From the anterior aspect it is fused with 

 an equally wide, lateral, opaque, black stripe, extending 

 to the middle of the humerus. In some lights the trans- 

 verse suture is grey pollinose and from a posterior view 

 the medial and lateral black stripes are narrowly sepa- 

 rated by grey pollen and the whole posterior aspect 

 of the mesonotiun and scutellum tends to be covered 

 with pale grey pollen and in places with a little reddish 

 pollen. There is some reddish pollen in front of each 

 postcallus, immediately behind the suture above the 

 wing, narrowly on the notopleuron and extensively 

 on the humerus, the dorsal part of propleuron, and 

 upper part of mesopleuron. Eemainder of pleuron 

 densely, greyish yellow pollinose. Haltere reddish 

 brown, the stalk paler. Scutellum comparatively thin- 

 ned apically with impressed rim and only a few minute, 

 black and white setae on the margin, a few others 

 on the disc. Metanotal callosities with yellovrish, bristly 

 pile. Metapleuron with a vertical row of 6 long, stout 

 bristles and 1 or 2 more slender ones. Propleuron widely 

 dissociated. Lateral bristles of the mesonotum stout 

 and long. There are 2 notopleuron, 1 supraalar, 1 su- 

 prapostalar, 1 or sometimes 2 postalar, 2 long, stout 

 pairs of postdorsocentral bristles, 1 shorter, postdorso- 

 central bristle. Mesonotum with scattered, appressed, 

 spinous, black setae anteriorly and 2 or 3 differentiated 

 rows of acrostical setae. Only the lateral portion of 

 the propleuron bears bristles where there is a vertical 

 row of 4 bristles placed anteriorly. 



Legs : All the femora are stout, a little narrowed at 

 base and apex, especially towards the base of the hind 

 femur. Hind tibia a little swollen apically. The legs 

 are imifonnly, light brownish orange, the last tarsal 

 segment a little darker. The apices of all the tibia with 

 a lateral, blackish spot ; the anterior 4 femora with a 

 sharply demarcated, anterior, black stripe ; the hind fe- 

 mur with a similar, lateral, black stripe. Pile rather 

 abundant, flat appressed, coarse and setate, golden on 

 the liind femur, golden anteriorly on the anterior femur, 

 golden anteriorly and posteriorly on the middle femur 

 and black dorsally on the first four femora, black dor- 

 sally and laterally on the hind tibia and most of the 

 anterior and middle tibiae. Bristles black and stout, 

 with the exception of the posterior bristles on the an- 

 terior and middle tibia, which are reddish yellow. Hind 

 femur with 3 prominent, dorsolateral, 7 ventrolateral, 

 2 of which are at the apex, 2 black, dorsomedial near the 

 apex, 6 yellow ventromedial, and 5 yellow, ventral bris- 

 tles. Bristles of hind tibia consist of 2 black ventro- 

 lateral elements on the outer half, 2 prominent, basal, 

 dorsal, black bristles side by side, and 2 long, stout, 

 reddish bristles laterally at basal and apical third. 

 Middle femur with a ventral row of 7 short but quite 

 stout, black bristles and 1 long, red bristle in the same 

 row at the base. It also has 2 prominent, anterior, black 



