478 



UNITED STATES NATIONAL MUSEUM BULLETIN 224 



the tihird vein arising as a crossvein with a basal spur; 

 other species groups are without the crossvein and tlie 

 anterior branch arises gradually. The fourth posterior 

 cell is closed and stalked ; alula large, the ambient vein 

 complete. Those species with three complete marginal 

 cells belong properly in the genus Efferia Coquillett. 



Abdomen : The abdomen is robust at base ; only the 

 first tergite is as wide as the mesonotum ; the surface is 

 generally pollinose, often with bands or spots of silvery 

 pollen and in some groups with divided hair-flocks 

 across the top of the tergites. Pile generally very 

 scanty, appressed, fine and setate, but longer laterally, 

 at least on the first segments, and either short, or ex- 

 tremely long on the first several sternites. Only the 

 first tergite has bristles. ]\Iales with eight tergites, the 

 last short, with only membrane exposed medially. Fe- 

 males with seven tergites before the ovipositor. Male 

 terminalia characteristically large, elongate, clublilve. 

 The superior forceps usually quite long, generally com- 

 pressed laterally. The gonopod is not as long but quite 

 proinment and often has fringes of ventral hairs; hy- 

 pandrium short, collarlike, extending high up on the 

 sides at the base of the terminalia. The female termi- 

 nalia characteristically with a quite elongate, strongly 

 compressed eighth segment; the ninth segment similar 

 but much shorter; the terminal proctiger is small and 

 finely pilose. 



Distribution: Nearctic: Nerax aestuans Linne (1767) 

 [ = aestuans Fabricius (1805), aestuans Macquart 

 (1834), hastardii Macquart (1838), incisvralis Mac- 

 quart (1838), macrolabis Wiedemann (1828), nigei' 

 Wiedemami (1821), tibialis Macquart (1838)]; ana- 

 capai Wilcox and Martin (1945) ; antiphon Walker 

 (1849) ; apicalis Wiedemann (1821) [ = vicinivs Mac- 

 quart (1846)] ; argentifrons Hine (1911) ; argyrosoma 

 Hine (1911) ; aridus Williston (1893) ; ajvnatus Hine 

 (1918); a^irimystaceus Hine (1919); auripihis Hine 

 (1916) ; barhatus Fabricius (1805) [ = alhibarbis Mac- 

 quart (1838), cimrascens Bellardi (1861), furax Wil- 

 liston (1895), pogonias Wiedemann (1821), tricolor 

 Bellardi (1861)]; belfragei Hine (1919); benedicfi 

 Bromley (1940) ; bexai^ensis Bromley (1934) ; hicauda- 

 tus Hine (1919) ; calif ornicus Schaeifer (1916) ; canel- 

 lus Bromley (1934) ; camis Hine (1916) ; dementi Wil- 

 cox and Martin (1945) ; coquillettii Hine (1919) ; cres- 

 soni Hine (1919) ; cuervamis E. Hardy (1943) ; dii:bius 

 Williston (1885) ; femoratus Macquart (1838) ; grandis 

 Hine (1919) ; harveyi Hine (1919) ; helenae Bromley 

 (1951); infatus Hine (1911); interruptus Macquart 

 (1834) [ = a'rnbiguus Macquart (1846), lateralis Mac- 

 quart (1838), maculatus Macquart (1838)]; jubatus 

 Williston (1885) [= proliflcus Osten Sacken (1887)]; 

 kans&nsis Hine (1919); knmvltoni Bromley (1937); 

 latrunculus Williston (1885) ; leucocomus Williston 

 (1885) ; mesquite Bromley (1951) ; monki Bromley 

 (1951); nemoralis Hine (1911); notabilis Macquart 

 (1838) ; paWululus Hine (1911) ; pilosus Hine (1919) ; 

 plenus Hine (1916); prairiensis Bromley (1934); 

 pratti Hine (1919); productiis Hine (1919); rufi- 



iarbi-s MacqnaTt (1838) [= aestuans Wiedema,nn (1821) 

 not Linne, completus Macquart (1838), dascyllus 

 Walker (1849), ravus Coquillett (1893), virginianus 

 Wulp (1882)]; slossonae Hine (1919); snoioi Hine 

 (1919) ; stramineus Williston (1885) ; spiniventris Hine 

 (1919) ; subaridus Bromley (1940) ; subcupreus Schaef- 

 fer (1916) ; subpilosus Schaeffer (1916) ; fagax Will- 

 iston (1885) [=si'milis Williston (1885)]; tabescens 

 Banks in Hine (1919) ; tanneri Bromley (1938) ; tex- 

 aniis Banks in Hine (1919) ; tricellus Bromley (1951) ; 

 truncatusl^vci^ (1^11) ; hihercuJattis Coquillett (1904) ; 

 utahensis Bromley (1938) ; varipes Williston (1885) ; 

 vertebratus Bromley (1940) ; wilcoxi Bromley (1940) ; 

 willistoni Hine (1919) ; zonatus Hine (1919). 



Neotropical: Nerax aMominalis Wiedemann (1821) ; 

 a/^n/s Bellardi (1861) [ = 7narginat'usBe].hrdi (1861)]; 

 albescens Schiner (1868) ; albicans Carrera and d'An- 

 dretta (1953) ; albispinasvs^iacqnart (1849) ; amazoni- 

 cns Bromley (1934) ; amphissa Walker (1849) ; aper 

 Walker (1855) ; argyrogaster Macquart (1846) ; auri- 

 barbis Wiedemann (1821) ; aunvestitits Hine (1919) ; 

 bad.iapex Bromley (1928) ; bardyllis Walker (1849) ; 

 bicolor Bellardi (1861); bilineatvs Wulp (1882); bi- 

 maoulatus Bellardi (1861) ; brunnescens Bromley 

 (1929) ; cainposlatia Curran (1931) ; carinatus Bellardi 

 (1861) ; cazieri Cwrraw (1953) ; celUtus Schiner (1868) ; 

 chapadeneis Bromley (1928) ; chiUensis Macquart 

 (1849) ; cinereus Philippi (1865) ; cingulatvs Bellardi 

 (1861) ; cockerellorum James (1953) ; comafns Bellardi 

 (1861) ; commiles Walker (1851) ; concinnatvs Willis- 

 ton (1901) ; costatus Schiner (1868) ; cvhensis Bromley 

 (1929) ; culi^iformis Walker (1855) ; ciirrani Bromley 

 (1951); demifasciatus Macquart (1849); dilectus 

 Walker (1855) ; disjunctus Williston (1901) ; eurylabis 

 Wiedemann (1828) ; eximius Bellardi (1861) ; favidus 

 Macquart (1838) ; ■flavid^^s Wiedemann (1828) ; favo- 

 fasciatus Wiedemann (1828) ; frdvibarbis Macquart 

 (1848) ; fulvithorax Macquart (1838) ; fiiscanipennis 

 Macquart (1849) ; fuscipennis M.ac({na.vt (1847) ; fiiscus 

 Wiedemann (1828) ; haloesiis Walker (1849) ; heferop- 

 terus Macquart (1846) ; htibbelli James (1953) ; hyali- 

 pennis Macquart (1838) ; imbuda Curran (1934) ; labi- 

 dophorus Wiedemann (1828); lades Walker (1849); 

 lascivus Wiedemann (1828) [ = amarynceus Walker 

 (1849)]; ?oew« Bellardi (1862) [ = dolichogasterW\\- 

 liston (1901)] ; medianus Wiedemann (1828) ; mellinus 

 Wiedemami (1828); mexica.nus Hine (1919); mlgdon 

 Walker (1851) ; minor Macquart (1847) ; murinus 

 Philippi (1865) ; m^rmtw Wiedemann (1821) \nignpes 

 Macquart (1849) ; nigritarsis Hine (1919) ; obscunis 

 Macquart (1838) ; pachychaetus Bromley (1928) ; par- 

 phorus Walker (1857) ; parvulus Bellardi (1861) ; par- 

 vus Walker (1855); patagoniensis Macquart (1849); 

 pavidus Williston (1901) ; pemiger Schiner (1868) ; 

 pictipennis Schiner (1868) ; pilosulus Bromley (1929) ; 

 poecilola7npriis James (1953) ; portoricensis Hine 

 (1919) ; potamon Walker (1857) ; propinqwus Bromley 

 (1928) ; pulchripes Bromley (1928) ; pumilus Macquart 

 (1849) ; pumilus Walker (1855) ; pyrrhogonus Wiede- 



