13G Descriptions of Scymnus discoideus, (Sfc. 



one-third ; there is no evident difference in the sexes in this respect, 

 as is seen in some otiier species. 



The above description is founded upon six male specimens and 

 two females, which I found under rejectamenta, by the River 

 Medway, near Roclicster, in February, 1857; the insect, then, 

 may possibly be confined to situations within the influence of salt 

 or brackish water. 



X. On the Euphorbia-zVi/es^f??^ Coleoptera of the Canary 

 , Islands. By T.Vebnon WoLLASTON,Esq.,M.A., F.L.S. 



[Read 6th May, 1861.] 



There are few facts in Entomology more extensively true, than 

 that the most peculiar insects of a region are usually to be found 

 either dependent on or inhabiting the same area as its most pe- 

 culiar plants. Accepting this as an axiom, I have never failed to 

 derive much practical aid, in every country which I have yet 

 explored, from ascertaining in the first instance not merely the 

 general character of the vegetation, but also the particular plants 

 in which it is naturally most prolific, and the tracts where they 

 occur ; for experience has invariably shown me that it is from 

 such tracts that the entomologist will, in the long run, obtain In's 

 greatest treasures. I do not say that these regions must always 

 be the most productive as regards the number of species ; far from 

 it, — for they may often occupy high elevations, difficult of access, 

 which the host of colonists gradually naturalized below has failed 

 to reach ; but I think it is not too much to aflfirm, that the insect 

 population of such localities is par excellence the truly indigenous 

 one, and that consequently the tenants of these spots have a greater 

 claim to be the avroyBoviQ of the soil (and probably, therefore, to 

 a great extent, endemic) than those of any other. 



That the fact is universal, even despite the undoubted repul- 

 siveness of certain plants to the generality of the insect tribes^ 

 there is good reason to suspect. Few trees, for instance, in their 

 chemical properties, could be more unattractive, one would ima- 



