132 ['^P"i' 



The term Emfleuri should not be used formally in a systematic 

 manner, the reason being that the various features its members present 

 (as given above) ai-e all, when not merely negative, found in different 

 degrees of development among the other Helophori. This fact, as 

 well as the large proportion of negative characters, will probably 

 suggest that the Em/pJeuri are ancesti'al to the other Helophori nl, and 

 if we use the term ancestral in a vague sense this idea may prove to 

 be correct. 



The transitions from Enipleuri to the aquatic Helopliori are to be 

 found chiefly in the genus E utriclieJophonis , the habits of which are 

 quite unknown to me ; until this gap in knowledge has been removed, 

 it is unprofitable to consider general questions as to adaptation and 

 phylogeny. 



Thomson (in Skand. Col. X, p. 298) discussed Emplenrus Hope, but 

 did not consider it a valid genus because of difiiculties in the case of 

 flelopliorus fhinlcus. He pointed ovit the difference of Enip/euriis 

 from other Helopliorini, as to the supra-pleural area, but he failed to 

 observe other important characters of the Empleuri, and also that 

 fennicus has a marked distinction in the structure of the part just 

 mentioned. I may add that he calls this part " epipleuron of the 

 prothorax," but this use of the term epipleuron can scarcely be 

 justified while " supra-pleural area" is at any rate free from error. 



Megempleueus, gen. n. 



Bugosus, the type of this genus, is the most advanced and distinct 

 form of Empleurus, and is indeed the one that authors have most in 

 mind when speaking oi " Empleurus. '' The genus of which it is the 

 type would therefore naturally itself take the name of Empleurus, but 

 as Hope specially named nuhiltis as the type of his genus, it is better 

 to continue to treat it as such, even at the cost of some jtemporary 

 inconvenience. 



The special characters of Megempletirus are: — 



Body and legs destitute of flexible hairs ; labial palpi quite bare ; abdomen 

 with minute pubescence only on the coxal band ; front margin of pronotum 

 very uneven ; wing well developed. 



The two species of the genus are not closely allied : though 

 generally undistinguished in collections they form two sub-genera. 

 Clypeus broadly rounded in front, not margined Megempleurus i, sp. 



Clypeus sub-tr\incate, raised and margined behind labrum... 



Simempleurus subg. n. 



