new genera and species of Acroceridce. 517 



otio fasciam rectam transversam formanti, in 4to maculara 

 trig'onam mediarn posticam formanti ; pedibus fulvis, tarsis 

 obscnrioribus ; abdomine infra nigro, segraentis late albo- 

 marginatis; alis hyalinis, veuis luteis, discoidalibus, vix 

 distinguendis. 



Long. Corp. lin. 3 ; expans. alar. lln. 6^. 



Habitat in Nova Hollandia. In ^lus. Hopeiano 

 Oxonia3. 



To the preceding genera and to those in Dr. Erichson's 

 monograph above referred to must be added the following, 

 which have been subsequently described in isolated 

 articles : — 



Genus ExETASiS (Type JS. tumens, Brazil), "Walker in 

 Insecta Saundersiana. 



Genus EuLONCnus (Type E. tristis, Loew, in Berlin 

 Ent. Zeits. xvi. California, and E. Smarogdiyuis, 

 California, Gerstacker in Stettin Ent. Zeitung, 1856, 

 where additional species o^ Acrocera, Ogcodes and Ocricea 

 are also described). 



Genus Arrhtnchus ( Type A. vittatus, Chili), Philippi 

 in Stettin Ent. Zeitung, 1871. 



Genus Thersites (Type TJi. jacobceus, Santiago), 

 Philippi in Stettin Ent. Zeit. 1871. 



Genus Opsebius (Type O. injiatus, S. Europe), Loew 

 in Beschr. Europ. Dipt. ii. p. 1, where several addi- 

 tional species of the family are described. 



Genus Mesopiitsa (Type M. Australasia, Sydney), 

 Thomson in Eugenie Resa, p. 475. 



By way of supplement, the description and figure of a 

 new genus of Diptera belonging to the Asilida, but 

 agreeing with some of the Acroceridce in the elongated 

 proboscis and venation of the wings, are here introduced. 



Leptynoma. 



Genus novum e familia Asilidarum generibus Gonypedi 

 (corpore valde elongate) et TlilipsomyzcB (proboscide 

 longissima) affine. 



Caput parvum, transversum, oculis magnis, spatio 

 angusto in medio faciei relicto ; ocellis tribus verticalibus. 

 Antennre in medio faciei inter oculos insertSB, parvte; articulo 

 Imo oblongo, 2do minuto, 3tio basi ovali apice in setam 

 longam desinenti. Proboscis gracillima, dimidio corporis 



