232 HYDROPHILID.E. [L/l/UiehillS. 



sometimes lighter ; the last ventral segment of the abdomen is furnished 

 with two long hairs which often meet together ; legs lighter or darker 

 testaceous, femora darker; male with the first joint of anterior tarsi 

 dilated. L. f mm. 



Very local ; ponds and ditches ; exceedintcly abundant in Askham Bos:, York, and 

 I have also taken it at Stamford Bridge; Knovvle, near Birmiugham ; Hunstanton; 

 Lancaster. 



Pale varieties of some of these species are occasionally found, in which 

 the upper surface is entirely or almost entirely testaceous with the head 

 darker. 



CHSITARTIZIIIA, Stephens. 



This genus comprises about half-a-dozen species, which are found in 

 Europe, the Canary Islands, and North America ; they are small and 

 very convex insects', resembling small examples of Agathidium ; our 

 single species is found in damp moss at the edges of ponds or streams ; 

 the genus is remarkable for the plates that cover the first two ventral 

 segments of the abdomen. 



C seminulum, Herbst. Very convex, almost hemispherical, shining 

 black ; liead smooth, antennfe and' palpi red ; thorax with the sides 

 margined, smooth ; elytra as broad as thorax, margined, feebly punctured, 

 with a sutural stria, and a feeble stria on external border ; underside 

 reddish brown, L. 1-1| nim, 



Kather local but not nncommon ; London district ; Wicken Fen ; New Forest; 

 Guniley, Market Harborough ; Cannock Chase ; Repton ; Askham Bog ; Liverpool ; 

 Northumberland ; Scotland, local, in damp mosses, Tweed, Solway, Tay, and Moray 

 districts. 



SPERCHEINA. 



The Spercheina are distinguished from all the other Ilydrophilidfe 

 by their emarginate clypeus and long triangular scutellum, and also by 

 their general contour ; their legs are not adapted for swimming, and they 

 progress slowly along the surface of the water with their back down- 

 wards ; one genus only, Spercheus, is included in the tribe : the American 

 genus, Sperchopsis, Leconte, forms a portion of Hydrohius, and has no 

 connection with Sp)ercheiis. 



SPERCHEUS, Kugelann. 



This genus comprises about half-a-dozen species, which are found in 

 Europe, Egypt, Senegal, Java, and New Caledonia; besides the cha- 

 racters mentioned above, they are remarkable for the form of the external 

 lobe of the maxilla, which is long, palpiform, and subulate, and by some 

 of the old entomologists has been mistaken for a true palpus ; the an- 

 tennse are apparently six-jointed, the last five joints forming an invgular 

 club j one species only is found in Europe, S. emarrjinatus : the larva of 



