1900.] 



147 



reaching beyond wing middle, and legs soaievvhat paler, otherwise like 

 rufipes but paler." 



Melonocephala, v. Ros. — A well-known species, found always 

 indoors so far as my experience goes Melanoceplialn is one of the 



very few yellow species in which 

 the colouiMug of thorax and ab- 

 domen is constant. Its incon- 

 stancy in others is singular, and 

 a matter for regret, since it 

 precludes the use of what other- 

 wise might have proved a valuable 

 character for the purposes of 

 segregation. The accompanying figure has been kindly drawn (as 

 have all the others) by Mr. Collin, to illustrate the application of 

 the terms used in describing the male hypopygium. It represents the 

 fully exserted organ of melnnocephala in the quiescent state, that is, 

 with the ventral plate lying flat against the under-side of the hypo- 

 pygium, and closing, as by a lid, its lower outlet, a = anal organ, 

 h = hypopygium, c = ventral plate. 



Frontalis. — Scarce. An odd one or so has been picked up in 

 every month of the year from June to October inclusive. The chief 

 locality has been Westhide Wood, but Stoke Wood and Coldborough 

 Park have also produced it. Among all the numerous forms in 

 Section C, it is the only one in which a long costal fringe, bare pleurae 

 and distinctly ciliated tibia? are associated with black halteres, and by 

 this combination of characters it should be at once recognised. 



Infraposita. — Rare. Just half a dozen, all males, have been met 

 with quite casually, one at a time, and in widely separated localities —my 

 own garden, Stoke and Westhide Woods, Coughton Marsh, near Ross, 

 and on the banks of the Monnow in the south-west of the county, the 

 captures having been evenly divided between the two months of July 

 and October in the years 1904.— 8. The essential character is the 

 distribution of the bristles on the frons, which follows the same lines 

 as in rudis but in a more complete form, the inner bristle of the lower 

 frontal row being now close to the eye margin and in vertical line with 

 the outer one. The slight tinge of red on the black thorax makes it 

 probable that one day a light coloured (yellow or red) form 

 will turn up. 



Vernal is. — Originally found in the spring — hence its name, and 



P3 



