12 PROCEEDINGS OF THE NATIONAL MUSEUM vol.69 



Genus EUSIMULIUM Roubaud 



EusinnUUun Ko.b.vo. Comp. Rend. Ac.d. ^u Pan., ^^ ^ 3^6^^ ^. 

 Pro.i;m/?/«m. Malx-och (part), U. S. Dept. Agric. Bur. Ent., Tech. Sei. No. 



Fro.lmS«t ENDERLE.N (part). Deutsch. Tierarz. Woch., Hanover, 1920; 



Zool. Anz., vol. 53. 1021, p. 43. „ , . ^i 



CteXia ENDEKLKiN, Deutsch. Tierarz. Woch., Hanover, 1920; Zonl. Anz. vol. 



Xevcrmmuiia Enderlein. Deutsch. Tierarz. Woch., Hanover. 1920; Zool. 

 Anz. vol. 53, 1921. p. 44. . , i i. i ^„ 



Crenotvpe.-SwiuUum aurcum Fries. This species must be taken 

 as the genotype since it was the only species mentioned under 

 Ensimulimn when Houbaud established the genus. 



Eushmilmm differs from Proshnulium chiefly by having the radial 

 sector simple (i. e. R,.. is absent). The pilosity of the en ire 

 lenoth of the radial vein distinguishes it from Simulium In other 

 respects it is intermediate between Prosimulium and Simulmm. ihe 

 foi-e tibia is usually without silvery pollinosity and the fore tarsi 

 are usually slender and cylindrical {am^eum has the fore tibia some- 

 what silvm-y pilose and the fore tarsi somewhat oroadei-). J he 

 hind basitai-,«us has the apical projection and the hmd second tarsus 

 has a more or less well defined dorsal incision in certain species. 

 The abdomen is opaque, rarely subshining, the chitmous plates two 

 to six are reduced in width and the abdominal venter is almost 

 entirely membranous. 



TABLE OF SPECIKS OF EDSIMDMUM ROUBAUD 



(Based on female hypopygia. OMusum and puoetense, founded on males, 



omitted) 

 Ovipositor flaps vevy large, extending to tips ot anal lobe,_. trisoni. new spWe«. 



°'r:.'t.,l-'':(Te"fen.ale greatly reduce.,, the ventral areas l^aring short 



Anal lobes chitinized and curved aureum (Fnes . 



Anal lobes not more chitinized than cerci. 



ventral portion of anal lobe broad, curved, and with dense ^P-^l^^^J^!^; 



mexicanum (Bellardi). 



the margin 



Ventral portion narrowly produced and with fine setae. 



^ callidum. new species. 



Ventral lobe rounded with few short tubercular setae. 

 Lateral plates of genital rod without chitinized ridge 



mutatum (Malloch). 



These plates with median chitinized ridge permutatum, new race. 



Anal lobes of female moderate not modified into special shape. 

 Lateral arms of the genital rod each with central tooth. 

 This tooth small and irregular, the arms widely divaricate. 

 " "Z.. .u ^a • 1^ dacotense, new species. 



This tooth single „"r^ MJiu^^^ 



I pecuaium ( luie> } . 



This tooth double or irregular 1 congareenarum, new species. 



