MYDAID^E. 63 



TABLE OF GENERA. 



1. Terminal segment of the 9 abdomen with a circlet of spines. . 2 

 Terminal segment without circle of spines.* . MTDAS Fabricius. 



2. A small cross-vein runs into the hind margin of the wing between the 



anal cell and the tip; hind tibiae of 9 with spurs. 



ECTYPHUS Gerstaecker. 

 No such small cross-vein ; hind tibiae of 9 without spurs at the tip. 



LEPTOMYDAS Gerstaecker. 



21. BOMBYLIID.E. 



Medium sized to small flies ; often with abundant, long, del- 

 icate pile. Head as broad or narrower than the thorax, often 

 spherical in shape, closely applied to the thorax. Eyes large, 

 often contiguous above in the $ and rarely also in the 9. 

 Antennae porrect, usually of but moderate length ; third joint 

 simple ; style usually small and indistinct and sometimes 

 wholly wanting. Ocelli present. Proboscis usually project- 

 ing from the oral cavity, and slender ; sometimes elongate ; 

 at other times short, with broad labella. Abdomen composed 

 of from six to eight segments, slender in a few genera only. 

 Legs moderately long, weak, with short, weak bristles or 

 spines. Pulvilli sometimes rudimentary, the empodia almost 

 always so, the tarsi and claws small. Tegulae small. Wings 

 often with dark markings; two or more submarginal, three or 

 four posterior cells present; discal cell present in all our 

 genera ; anal cell closed in or near the border of the wing, or 

 narrowly open. 



The family Bombyliidse comprises about fifteen hundred 

 known species. Most of them are swift flying insects, often 



* "Generis Ectyphi proximum, differt: antennis elongatis, segmento pe- 

 nultimo cylindrico, ultimo, 9 circiter duplo longiore, compresso, basi 

 parum dilatato, apice obtuse acuminate 9 duplo breviore, obtusiore, abdo- 

 minis segmento ultimo inermi, cyathiformi, utrinque, parum dilatato. 

 Long. c2o mm. undique niger, abdomine nitente, alis violaceo micanti- 

 bus, extreme apice albidis P. phyllocerus, Rocky Mts." 



PHYLLOMIDAS Bigot. 



