Insects. 4531 



Hydroporus nigrita, Fab. = trivialis, Steph. This species has 

 been overlooked by Schaum, and is not included in his catalogue. 

 I have taken it on several occasions in Norfolk in small road-side 

 grassy puddles. Never in deeper ditches or pools. 



„ rufifrons, Dufts. Whittlesea Mere. 



„ oblongus, Steph. Of this rare and beautiful insect 



I took five examples in and about Horning, Norfolk, May, 1854. 



„ Gyllenhalii, Schiodte. In the district of Whittlesea 



Mere, occasionally met with. 



„ tristis, Payk. In abundance near Oban, Argyle, in 



peat-holes on the hills. I took what I believe to be a constant 

 variety of this species in a lake by Achnacraig, Mull. 



„ angustatus, Sturm. In profusion in Huntingdonshire : 



one specimen near Crinan, Argyle. 



„ obscurus, Sturm. Plentifully in Argyle, near Connel 



Falls. 



„ umbrosus, Gyll. This species is apparently very local. 



I took several specimens in boggy ground near Norwich, in a little 

 swampy puddle of most uninviting aspect. 



„ granulans, Fab. Not uncommon. 



„ geminus, Fab. Common in shallow, muddy, fen 



ditches near Peterborough. This insect, like assimilis, Payk, seems 

 to prefer open shallow water to the cover of weeds. 



Besides the above, I have two or three species which cannot be 

 referred to any known British species : one which I took near Oban, 

 September, 1854, has been determined by Mr. Adam White and 

 Dr. Power as H. melanarius, Sturm, of the European collection in 

 the British Museum. 



Agabus agilis, Fab. Among weeds and in grass-margined ditches 

 in Norfolk : once in some abundance in Horning Fen. 



„ arcticus, Payk. In a lake in Orogan, Isle of Mull, Sep- 

 tember, 1854. I took the insect only by wading, and brushing with 

 my net a species of short grass that covered a small rock at the 

 bottom of the lake, in three or four feet water. 



„ striolatus, Gyll. This is an early spring insect : it may be 

 distinguished from all other species by its very parallel sides. I took 

 one specimen in Horning Fen, May, 1854. See note by Schaum, 

 Zool. 1932. 



Colymbetes notatus, Fab. This insect is certainly local, but when 

 found not uncommon ; Whittlesea Mere, 1853. 



„ bistriatus, Bergst. In small pools on hills near Oban, 



and also in Mull, September, 1854. 



