1915] 131 



the British Museum, but the Helophorini have been entrusted to me by 

 the authorities, as well as many from the Fry collection and other 

 sources, for study, many of the forms being unnamed. My chief object 

 in these studies is, in fact, to bring order into this collection, and next, 

 to elucidate our British species. Of the latter I have collected and 

 examined many hundreds — I think I may say thousands — of specimens. 

 Mr. Champion has entrusted me with his foreign collection of Helo- 

 phorini, which contains several very interesting Mediterranean forms 

 collected a. good many years ago by Commander Walker, and he has 

 also sent me some valuable British examples of the group. Mr. Balfour 

 Browne has given me access to the charming collection he has formed, 

 and Mr. Jas. Edwards, who has long been interested in Helophorus, 

 has answered various questions I have addressed to him. To all these 

 gentlemen, as well as to Commander Walker and others who have 

 from time to time sent me specimens, I tender my sincere thanks. 



In order to save space I shall not give references and synonymy 

 that may be found in all the books, and that are accessible in Zaitzev's 

 catalogue already referred to. 



I have already stated (ante p. 3) that the non-aquatic Helophorini 

 show so many points of distinction from the aquatic forms that 

 they should form at least a distinct genus. Fuller investigation 

 induces me to form them into several genera. Only five species of 

 non-aquatic Helophorini are known to me, and they are so different 

 among themselves that they form three genera and a sub-genus, 

 together constituting the group Empleuri. 



The characters of this group are as follows. Maxillary palpi with 

 the terminal joint symmetric, nearly oval, but approximating to being 

 pointed at the tip ; labial palpi small, bare (except in Empleurus 

 proper) . Outline of pronotum very waved on the front margin in two 

 directions. Elytra costate ; pubescent epipleuron, very small ; the 

 10th interstice broad and flexed to the underside, so as to form an ex- 

 tensive pseudepipleuron. Pubescence (as distinguished from setae) of 

 abdomen, much reduced. Body and legs entirely destitute of flexible 

 setae (the swimming hairs of Kuwert) . Supra-pleural area large. 



The genera are : — 



Labial palpi setose Empleurus Hope. 



Labial palpi bare : 



Abdomen bare, wings well developed Megempleurus gen. n. 



Abdomen with minvite pubescence on basal 



and apical segments, wings atrophied . . .Bradempleurus gen. n. 



K 2 



