4194 Insects. 



These three species are dwellers in peat-bogs, and mossy holes, on 

 wild elevated moors ; I found all three in company, this last season, 

 when in Cumberland at the latter end of July. H. Gyllenhalii is 

 very rare ; tristis and obscurus are more abundant, but by no means 

 common. I have also taken them in similar localities in this district, 

 but more sparingly. H. obscurus varies considerably both in size 

 and colour, some specimens being almost minute. 



H. memnonius, Nicolai. This variable insect is common with us, 

 and appears to adapt itself to a great range of habitat, being found 

 equally abundantly in ponds, ditches, streams, wells and horse-troughs. 

 I sometimes fancy that the specimens from clear water are the most 

 brightly coloured. 



H. angustatus, Sturm, = H. tristis, Steph. Likewise common in 

 our district, frequenting, by preference, the foulest ponds and ditches. 



H. umbrosus, Gyll. — H. minutus, Steph. This, one of the most 

 obscure, is one of the most local of our Hydropori. I met with it 

 at Gosforth, where it frequents an extensive pond, which is almost 

 choked up with Equiseta and other aquatic plants. 



I have often noticed how exceedingly local are some insects in their 

 distribution ; and, in this instance, so much so, that I was strongly 

 impressed with the necessity of examining every portion, however un- 

 promising, of our hunting-ground. Though I had dredged all the likely 

 and many unlikely ponds in the vicinity, yet had I always shunned this 

 particular one ; for having once or twice dipped my net into it in 

 passing, such was its filthy condition, that I always shook out the un- 

 examined contents with disgust. However, one day, in a very wet 

 season, not being able to make progress elsewhere, from the damp 

 state of the woods, I paid it a visit, and finding it clearer than usual, 

 from being brim-full, I tried my net, and at the very first haul secured 

 insects that I had in vain sought for elsewhere. After this, it scarcely 

 need be mentioned, that I worked with a will, and finally came home 

 richer by nearly a dozen species, every one of which was an addition 

 to our local Fauna. 



H. granulans, Fab. Not uncommon in one or two places in the 

 district, where it is found in ditches accompanied by H. pictus. 



H. geminus, Fab. This is one of our rarest species, and confined 

 to one locality, where it is found very sparingly. 



Thos. Jno. Bold. 

 Angas' Court, Bigg Market, 



Ncwcastle-on-Tyne, December 27, 1853. 



