86 



UNITED STATES NATIONAL MUSEUM BULLETIN 224 



Wings: Marginal cell open, slightly less than the 

 maximum width; anterior branch of third vein sig- 

 moid, strongly arched at base and ending shortly before 

 the apex; posterior branch ends far behind. First 

 posterior cell narrow throughout its length, narrowly 

 open; fourth posterior cell closed with a short stalk; 

 anal cell closed. Alula rather large; ambient vein 

 complete. 



Abdomen: The abdomen is robust, as wide as the 

 mesonotum, a little flattened on the tergites. There are 

 six tergites present in the male, the sixth but little 

 shorter than the seventh; pile of the abdomen dense, 

 rather short but flat appressed, longer and somewhat 

 more erect and quite dense laterally. Lateral bristles 

 absent on all tergites. Male terminalia rotate one-half, 

 moderately large, subbulbous on the basal portion of 

 the epandrial plate and rather deeply notched dorsally. 



Distribution : Nearctic : Triclis fiavipes Jones (1907) . 



Neotropical: Triclis argentifacies Williston (1901). 



Palaearctic: Triclis anatolicus Hermann (1920); 

 octodecimnotatus A. Costa (1893) ; olivaceus Loew 

 (1851) [=halictivorus Eondani in collections]; ntfes- 

 cens Austen (1914). 



The two American species, Triclis fiavipes and ar- 

 gentifacies, are probably closer to Zahrops Hull than 

 to Triclis, which appears to be a European genus. Only 

 a type study will determine their real position. 



Genus Hoplotriclis Hermann 



Figuees 18, 426, 983, 992, 1672, 1687, 2024 



Hoplotriclis Hermann, Zool. Jahrb. vol. 43, p. 186, 1920. Type 

 of genus : Dasypogon pallasii Wiedemann, 1828, by original 

 designation. 



Hairy flies of medium size, with tumid occiput and 

 convex, long pollinose face. The antenna is unusually 

 elongate and the third segment bears a long, blunt 

 microsegment, which is quite as wide as the third seg- 

 ment. The proboscis is short and robust and directed 

 forward. The wing is broad, with the first posterior 

 cell open but narrowed and the fourth closed in the 

 margin. The basal expansion of the second sub- 

 marginal cell lies half above and half below the third 

 vein. Length 16 mm. 



Head, lateral aspect : The head is unusually long and 

 the face prominent, rounded and bulging. The face 

 bears dense, long, yellow pile, stiff in character, aris- 

 ing from microtubercles. The pile extends from the 

 base of the antenna all the way down the face. The 

 occiput is unusually prominent, except at the vertex. 

 Upper portion of occiput with only stiff, yellow pile 

 and a few extremely weak bristles near the top. The 

 pile of the middle and ventral portion is long, dense 

 and fine. The proboscis is short, subcylindrical, basally 

 swollen, its apex subtruncate and pilose. The proboscis 

 is held directly forward. The palpus of two segments 

 is minute and cylindrical with long pile at the apex 

 and sides. The antenna is unusually elongate, longer 

 than the head, slender, of nearly uniform width. The 



third segment longer than the first two combined, and 

 bears a long, robust microsegment. First two segments 

 with fine setae above and below. 



Head, anterior aspect : The face below the antenna is 

 one-fourth the head width and only slightly divergent 

 below. The vertex is moderately excavated, the ocellar 

 protuberance high, with steep sides and numerous, long, 

 stiff hairs. The upper ocelli are visible in profile ; the 

 very large anterior ocellus is directed forward. Sides 

 of the front with 5 or 6 long, weak, yellow bristles. 



Thorax : The mesonotum densely covered throughout 

 with moderately long, shining, curled, pale hairs; lat- 

 erally this pile is ahnost matted in places. Humerus 

 densely pilose; notopleuron with two extremely weak 

 bristles scarcely discernible ; supraalar with two equally 

 weak bristles; postalar with dense pile. Scutellum 

 with abundant, moderately appressed pile without 

 bristles. Pleuron densely appressed, long, matted pi- 

 lose over the mesopleuron; pteropleuron with a few 

 hairs; hypopleuron with a large patch of long, ap- 

 pressed pile; metapleuron widely covered with long, 

 fine pile; slopes of the metanotum micropubescent but 

 without pile. Hypopleuron, metapleuron and meso- 

 pleuron micropubescent; pronctal collar densely long 

 pilose. 



Legs: All the femora are stout without being espe- 

 cially enlarged. The hind femur is somewhat longer 

 and densely covered with appressed pile which becomes 

 a little longer ventrally, especially towards the base, 

 where it is suberect ; bristles absent. The hind tibia is 

 stout from base to apex, a little wider at the apex, with 

 abundant, short, appressed pile; apex with moderately 

 long, reddish bristles : 2 lateral, 3 ventrolateral, 1 dor- 

 sal, 4 medial, and 2 ventral. In addition, laterally 

 near the apex are 2 small, short bristles. Bristles, 

 however, are absent on one side. Hind basitarsus 

 short, only twice as long as wide. Middle femur with 

 an anterior patch of numerous, stout, moderately long, 

 reddish yellow bristles confined to the basal half ; this 

 group contains 10 bristles altogether. The middle tibia 

 has 5 posterior and 4 weak dorsal bristles and at the 

 apex 2 dorsal, 1 posterior, and 4 ventral bristles, which 

 are stout. Anterior femur with a few, long hairs ven- 

 trally ; its tibia has 4 or 5 short bristles posteriorly ; apex 

 with 2 dorsal, 2 anterior, 3 or 4 ventral, 1 or 2 posterior 

 bristles, but without spine. Claws moderately long, 

 sharp, strongly curved at the apex ; the pulvilli is four- 

 fifths as long as claws, broad and flattened, truncate at 

 the apex; empodia from one-third to one-half as long 

 as claws, stout basally. 



Wings: The wings are broad, marginal cell widely 

 open, the second submarginal cell is only moderately 

 expanded at the base, and half of this expansion lies 

 below the third vein. First posterior cell open but nar- 

 rowed. Fourth posterior and anal cells closed in the 

 margin; ambient vein complete, including the wide 

 alula. 



Abdomen : The abdomen is rather stout but not quite 

 so wide as the thorax; the tergites are only gently 

 convex, the sides of the first tergite with long, subap- 



