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UNITED STATES NATIONAL MUSEUM BULLETIN 224 



brush of setae present. Middle femur with 2 weak 

 subdorsal bristles near the apex, the tibia dorsally with 

 5, anteriorly with 3, posteriorly with 5, and anteroven- 

 trally with 4, posteroventrally with 4 which are basally 

 quite long and stout. Anterior femur with a few, long, 

 fine hairs ventrally, its tibia with 2 or 3 short dorsal 

 basal and 2 longer bristles distally; and with short 

 anterodorsal, 4 posterior, and 3 quite long posteroven- 

 tral bristles. Tibial apex without spine; all claws 

 sharp ; the pulvilli in the type of genus reduced to one- 

 half the length of the claw; empodium long and blade- 

 like. In Lyphystia gigantella Loew the pulvilli are 

 of full length. 



Wings: In the type of genus the marginal cell is 

 closed, either in the margin or with a minute stalk. 

 The base of anterior branch of third vein emerges at 

 a right angle and is strongly arched. The posterior 

 cell is open though narrowed to half its maximum 

 width; sometimes closed; fourth posterior and anal 

 cells closed and stalked. The second basal cell ends 

 in 3 veins ; alula large, the ambient vein ends with the 

 anal vein. 



Abdomen : The abdomen is as wide as the mesonotum 

 or wider; it is typically densely and minutely, short, 

 appressed pilose. In the male there are 6 tergites only ; 

 in the female 7 or 8, the last 2 quite short, of equal 

 length, and about one-fourth as long as the sixth; 

 the eighth may be very largely concealed beneath the 

 seventh in some species. Sides of first tergite with 4 

 or 5 pairs of stout bristles and remaining tergites, with 

 a transverse row, a little beyond the middle laterally, 

 containing 2 to 5 and usually 3 or 4 stout bristles. Male 

 terminalia rotate one-half, rather large and conspic- 

 uous with a ventrally placed, bowl-shaped epandrium. 

 The true ventral side is open, exposing the interior; 

 the epandrium continuous and undivided, except for 

 apical sulcus; the apical margin often nearly trans- 

 verse. Gonopod large basally, as long as the epan- 

 drium, with one or more apically acute processes ex- 

 tending as far as the large, fused proctiger. Hypan- 

 drium triangular or short. The female terminalia are 

 composed principally of a single, apically notched, dor- 

 sal plate, rather small and barely protruding beyond 

 the last tergite. 



These flies are characteristic inhabitants of damp 

 mud and sand flats beside rivers, lakes, and ocean shores, 

 and are generally found close to the water's edge. 



Distribution: Nearctic: Laphystia falbiceps Mac- 

 quart (1846); annulata Hull (1957), annulata inter- 

 rupta Hull (1957) ; canadensis Curran (1927) ; confusa 

 Curran (1927); -flavipes Coquillett (1904); lanhami 

 James (1941); Umatula Coquillett (1904); litoralis 

 Curran (1931) ; notata Bigot (1878) ; ochreifrons Cur- 

 ran (1931); opaca Coquillett (1904); rubra Hull 

 (1957) ; rufwentris Curran (1931) ; rufiventris James 

 (1931) ; rufofasciata Curran (1931) ; sexfasciata Say 

 (1823) ; texensis Curran (1931) ; torplda Hull (1957)'; 

 varipes Curran (1931). 



Neotropical: Laphystia columbina Schiner (1868); 

 fasciata Lynch Arribalzaga (1880) ; robusta Hermann 



(1908); salti Curran (1931); schnusei Hermann 

 (1908). 



Palaearctic: Laphystia aegyptiaca~Efila.toun (1937); 

 arenacea Paramonov (1930) ; armeniaca Paramonov 

 (1930); carnea Hermann (1905); erberi Schiner 

 (1865) ; hispanica Strobl (1906) ; hypopygialis Para- 

 monov (1930) ; kashgarica Paramonov (1930) ; lati- 

 uscula Loew (1870) ; metallescens Hermann (1905) ; 

 sabuletorum Paramonov (1930) ; sabulicola Loew 

 (1847) ; turkmenica Paramonov (1930). 



Ethiopian: Laphystia argentio fasciata Engel 

 (1929) ; gigantella Loew (1852). 



Oriental: Laphystia stigmaticalis Bigot (1878). 



Verrall (1909) in his appendix list of Palaearctic 

 asilids mentions a Laphystia selenis Hermann from 

 Gobi. I have not found this species in the Zoological 

 Record and cannot give the date or say if it has been 

 published. 



Laphystiella, new subgenus 



Type of subgenus : Laphystia argentiofasciata Engel, 

 1929. 



Flies with comparatively long, fine pile and the mar- 

 ginal cell open in contrast to the Laphystia, sensu 

 stricto, in which the marginal cell is closed or is closed 

 in the margin. Face below with a row of stout bristles. 

 Proboscis much longer than face. This species is from 

 Rhodesia. Length 12 to 15 mm. 



Laphygmolestes, new genus 



Type of genus : Laphygmolestes flavipes, new species. 



Rather small flies characterized by minute, abundant, 

 flat appressed setae on the thorax and scutellum, some- 

 what longer, flat appressed setae on the abdomen, and 

 with an habitus strongly suggestive of Atomosia Mac- 

 quart. While the marginal cell is widely open, these 

 flies must be to a certain extent annectent between the 

 Laphystini and the Atomosini. The abdominal tergites 

 have strong bristles on the sides and the scutellum has 

 2 pairs of bristles. The face is not unlike Laphystia 

 Loew. In the key to genera this fly will go to Psilocurus 

 Loew. From both Laphystia and Psilocurus it is dis- 

 tinguished by the quite elongate, differently formed an- 

 tenna, and the different terminalia. Length 10 mm. 



Head, lateral aspect : The eye is rather hemispherical 

 from the anterior side but almost plane vertically from 

 the posterior side. The occiput appears in profile only 

 on the lower half of the head and is poorly developed 

 there. Lower half of occiput with numerous, coarse 

 hairs; bristles begin just below the middle of the head 

 and consist of 10 pairs on each side ; all of the bristles 

 are weak, including the upper elements. The face is 

 nearly plane with the eye, except on the lower third 

 which, while relatively short, is gently rounded and 

 gibbous. The whole face is micropubescent with 10 or 

 12 short hairs on the upper part. On the lower third of 

 the face there are 6 moderately stout, long, pale bristles 

 arising in the middle above the epistoma and also 3 or 4 

 additional and more slender bristles on either side, be- 



