244 



[November, 



2. P. ducalis Lw. : I once found this species in abundance on the 



edges of a small pond near Seaford on July 31st, 1887. 

 Before I caught it I had recognised that it was new to 

 Britain unless it was P. principalis, and then I found both 

 species on the pond. 



3. P. principalis Lw. : I first caught this near Bournemouth on July 



19th, 1871, and afterwards found it common in company with 

 the last species near Seaford on July 31st, 1887. 



8. RERCOSTOMUS Lw. 



Before using the table for this genus, it should be noted that it 

 is very difficult and very uncertain to decide upon the colour of the 

 lower postocular cilia in H. eretifer and H. fulvicaudis, while even in 

 H. parvilameUatus and //. nanus the cilia are often only brownish- 

 black. The fringe of the squamae seems to vai'y in colour according 

 to the aspect in H. eretifer. If, however, these notes are attended 

 to, the rest of the table is easy to work out ; many more species may 

 however be expected to occur in Britain. 



Lower postocular cilia pale. 

 AntennaB wholly black. 

 Femora yellow. 



Squaniffi pale fringed ; large species 1. gracilis Stann. 



Squamae black fringed ; small species. 



Front tarsi elongate, third and fourth joints deep black and dilated ; 



wings clear 2. eretifer Walk. 



Front tarsi simple ; wings browned. 



Larger species 3. germanus Wied. 



Smaller species 4. cheerophylli Meig. 



Femora black or blackish. 



Last joint of middle tarsi dilated ; large species. ..5. nigriplantis Stann. 



Last joint of middle tarsi normal ; small species ...6. nigripennis Fall. 



AntcnnfE mainly yellowish. 



Apical half of hind tibiae black ; front tarsi with black and white rings... 



7. chrysozygos, Wied. 

 Hind tibia all pale. 



Abdomen all metallic-green; small species 8. plagiatus Lw. 



Abdomen ferruginous at base ; tiny species 9. fulvicaudis Walk. 



Lower postocular cilia black. 



Legs wholly black 10. ntrovirens Lw. 



Legs pale, at least on tibia;. 



Femora and coxfB wholly blackish-brown ...11. parvilamellatxis Macq. 



Femora and front coxEB wholly yellow 12. nanus Macq. 



