DIPTERA OF BAJA CALIFORNIA. 599 



who has seen the type, is inclined to refer his females to 

 that species. 



19. Erax cinerascens Bellardi. San Jose del Cabo, 

 Baja California (Eisen). Twenty-seven females and one 

 male. Osten Sacken warns us not to confound this 

 species with the Mexican E. tricolor Bell., which has 

 black hairs in its mystax. All of the above specimens 

 have the mystax wholly whitish or yellowish. But the 

 twenty -seven females were taken in company with the 

 large number of males mentioned under E . tricolor, and 

 all of which had black bristles in the mystax. Only one 

 male was taken with a wholly whitish or yellowish mys- 

 tax, which makes it seem very improbable that this and 

 tricolor are distinct species, yet they may be so. 



20. Erax tricolor Bellardi. San Jose del Cabo, 

 Baja California. September. Twenty-two females 

 and thirty -eight males. These specimens all agree in 

 having black bristles in the yellowish -white mystax. 

 Otherwise the}' do not differ at all from E . cinerascens 

 Bell., and both forms occur extensively in company with 

 each other. 



21. Proctacanthus arno n. sp. 



San Jose del Cabo, Baja California (Eisen). Eleven 

 females and ten males. 



Length, $ , 31-38 mm.; ^ , 25-32 mm. Antenna? and 

 eyes blackish, front with black hairs, and some white at 

 anterior angles; face yellow, cheeks dark, the whole with 

 white beard extending on occiput. Thorax brownish 

 ashy, with a median pair of distinct dark brown vitta^ 

 which are attenuated posteriorly. Humeri somewhat 

 lighter, with a whitish pollinose area behind them along 

 sides of thorax. Pleura? and sternum grayish with gray- 

 ish hair. Abdomen more or less grayish or ashy on 



