130 DIPTEBA-' 



specimens, fit for dissection, are accessible. The question is, whether we have here a 

 mere outward resemblance or a real relationship. 



The species belonging to this group and described by me may be tabulated as, 

 follows : — 



The expanded distal end of the marginal cell hyaline. 



Axillary cell and more than half of the anal one hyaline. 



Abdomen with two distinct white cross-bands ...... 20. lepidota, sp. n. 



Abdomen almost entirely covered with a yellow tomentum . . 26. sp. ? 

 Axillary and anal cells, except their extreme ends, brown. 



Cross-veins and bifurcations, within the brown, with very distinct 



pale margins (or aureoles) 21. chimcera, sp. n. 



Cross-veins and bifurcations without any distinct pale aureoles 

 (except the usual pale spot at the proximal end of the 



discal cell) 22. eumenes, sp. n. 



The expanded distal end of the marginal cell more or less filled out by 

 a brown spot. 

 Axillary and anal cells, except their extreme ends, brown. 



The brown spot filling the expanded end of the marginal cell 

 followed by another smaller spot at the end of the first 



submarginal cell 24. sinuosa, Wiedem. 



No brown spot at the distal end of the first submarginal cell . 25. sp. ? 

 The distal half of the axillary and anal cells hyaline 23. scylla, sp. n. 



20. Anthrax lepidota, sp. n., s . (Tab. II. fig. 18.) 



Black ; a stripe of white hair between the humerus and the post-alar callosity ; cross-bands of similar hair on 

 the first and fourth abdominal segments ; tufts of longer and finer snow-white pile in front of the halteres 

 and behind them on the sides of the first and second abdominal segments ; the collar-like fringe in front 

 of the thorax and the tufts on the pleurae pale yellowish ; on the surface of the thorax are traces of an 

 appressed reddish-fulvous tomentum (mostly rubbed off in my specimen) ; surface of the abdomen with a 

 black soot-like covering of short, appressed, scaly hairs. Face and front black, with the usual black erect 

 pile and a pale yellow appressed tomentum ; face not conically protruding ; proboscis withdrawn ; antennae 

 (broken). Legs black ; hind femora and tibiae beset on both sides with conspicuous fringes of long black 

 scales. Halteres with a yellowish- white knob. "Wings : the dark brown of the antero-proximal half 

 begins at the axillary excision, fills about one third of the anal, the whole of the second basal, and the proximal 

 end of the discal cells ; encroaches upon the first posterior and first submarginal cells a little beyond the 

 anterior cross-vein ; and reaches the costa at the tip of the auxiliary vein — thus the extreme end of the 

 costal cell and the whole of the third and fourth posterior and axillary cells are hyaline. Except the 

 usual subhyaline spot before the proximal end of the discal cell, there are no other conspicuous paler spots 

 within the brown, nor any brown clouds in the hyaline portion of the wing ; the contact of the fourth 

 posterior and discal cells is short. 



Length 8 millim. 



Hah. Mexico, Northern Sonora (Morrison). A single male. 



It is possible that the female of this species has no fringe of scales on the hind legs. 

 The front tibiae (at least in my specimen, compare below) do not show any spinules ; 

 the joints of the front tarsi are rather distinctly marked ; the front ungues very small ; 



