It seems very doubtful whether it were necessary to form a 
genus for this group, it is so closely allied to Hyphydrus ; and 
although in H.jluviatilis and coiifluens 2 claws are very distinct 
in the posterior tarsi, I am not convinced of there being more 
than one with some long bristles, in the more convex species. 
The following are British insects. 
1. H. fluviatilis Lea. — Ste.pl . 1 1 . f. 2. 
April, in the river Cawdor, Carlisle, Dr. Leach ; Meldon 
Park, Mr. Wailes; Hebden Bridge; Netley, Salop; Mendip 
Hills, Mr. Streatfield ; and the Tavy, Devon. 
2. assimilis Payh . — Gyll. 1 . 522. 6. 
Aldborough, Yorkshire; Netley, and river Plym, Devon. 
4. confluens Fab . — Oliv. n . 40. pi. 5.f 44. — Pz. 14. 5. 
Newcastle, Mr. Wailes; Whittlesea Mere; in lily-pots, Yar- 
mouth, Mr. Paget; in stagnant water July, Wandsworth Com- 
mon and Copenhagen Fields ; end of April, middle of October, 
gravel-pits, Glanville’s Wootton, Mr. Dale ; Swansea, Mr. 
Dillwyn; Kimpton and Marton, Rev. G. T. Rudd. 
5. collaris Pz. 26. 4. — recurvus Mars. — affinis Ste. var. 
Pools, ponds and ditches, Wandsworth Common, Copen- 
hagen Fields, Swansea, Parley Heath, end of May, and Devon. 
6. reticulatus Fab,— Stephens gives this and also the following 
as the trifidus of Marsham. 
July near London; Swansea; end of October Parley Heath, 
Puddimore, and Devon. 
7. inaequalis Fab. — Oliv. pi. 3. f. 29. ?— trifidus Mars, ac- 
cording to Gyllenhal. 
Newcastle ; end of June, turf-pits, Bottisham and Swaffham 
fens; ditches Norfolk; Wiltshire; September and October 
Portland and Holwell, Somerset ; Swansea and Ireland. 
3. decoratus Gyl. — cuspidatus Ahr.? — Curt. B. E.pl. 53\. 
For specimens I am indebted to G. A. Wright, Esq., who 
took them the end of last July on Askam bog, near Tadcaster, 
“ in shallow puddles on the overflowed part of the bog, where 
the grass was very thick. In these places water insects of 
every description abounded, and the 11. decoratus seemed ex- 
clusively confined to them.” 
8. scitulus Spen. — Ste.pl. 11. f. 3. — lepidus Oliv.pl. 5. f. 51. var. ? 
Carlisle, Yorkshire, Cambridge, Wandsworth Common, 
Copenhagen Fields ; 12th of July, Parley Heath and New Fo- 
rest ; in a shady canal, Swansea, Devon, and Ireland. 
9. pictus Fab. — flexuosus Mars. — arcuatus Pz. 26. 1 . 
Newcastle and Yorkshire; May, ditches and streams Nor- 
folk, Wandsworth Common, and Hampstead ; August to the 
end of October Copenhagen Fields, ponds, Paddington and 
South-end ; Parley Heath, and stagnant waters Swansea. 
The Plant is Shim nodijlorum (Procumbent Water Parsnep). 
