350 Mr. H. Donisthorpe on 



protection than land species, being in a more confined 

 space and liable to the attack of such voracious creatures 

 as fish. 



Laccophihts. 



The colours of the species of this genus fall within the 

 above scale. Their ground-colour is broken up by flecks 

 of yellow. 



Agabus nebulosus, Forst. and A. conspersits, Marsh. 



In these two beetles the ground-colour is broken up by 

 specks of black. 



Dytiscus. 



The species of this genus are of an olive-green colour 

 with yellow margins to the thorax and elytra. 



A dims. 



In Acilius we find a similar linear arrangement of 

 yellow margins. 



Hydrophilim:. 



Helophorus. 



All the species of this genus have rough uneven upper 

 surfaces and are no doubt protected in the same manner 

 as the species of Maphrus, when on the wet mud and 

 margins of pools, etc. 



Sphseridium scardbmoidcs, F., and S. hipustulatum, F. 



Mr. Holland says of this genus, " the spotted species 

 look like lady-birds." This would be of service to them 

 as the Goccinellidse are known to be distasteful and are 

 mimicked by many groups. 



Cercyon. 



Of this genus, which mostly live in dung, Mr. Holland 

 suggests, " The red apex to the elytra of all the species 

 probably acts as a protection. Whew a cow-pad is dis- 

 turbed and the Cercyon laid bare, they dive at once head 

 first, thus exposing the posterior part, which is reddish, 

 like the dung." 



