1915.] 3 



Empleiirus ; when, however, these terrestrial Helophorids are compared 

 with the aqiiatic ones, so many points of distinction emerge that it 

 becomes certain that Emplenrus is at least a distinct genus. 



I find also that the differences amongst the aquatic Helophorini 

 are of sufficient importance to warrant their treatment as distinct 

 genera. The sub-genera of M. Zaitzev's catalogue are, in fact, more 

 naturally treated as distinct genera. 



These sub-genera are TrirJielophorus, Meghelophorns, Cyphelo- 

 phoriis, Atradhelophorm and Bhopalhehphorus. Uhopallielopliorus 

 should retain the name Helnphorus, with H. griseus as type, the types 

 of the other genera being Trichelopliorus alternans, Meghelophorus 

 aqimticus, djphelophorus tuherculahis, and Atracthelophorus arvernicus. 



I adopt this course because it is the one that involves the least 

 change. It is, in fact, the legitimate line of development if continuity 

 of nomenclature be considered as of gi-eater importance than artificial 

 laws, which in many cases contravene the very object for which they 

 are instituted ! Fabricius founded the genus Eloplioms (Syst. Ent., 

 p. Q&, anno 1775) for two species, Silpha aquatica L. and E. minuhts 

 sp. n. There are many who would argue that I ought now to obliterate 

 the interval between my writing and Fabricius, forget all that has 

 occurred in this long period of 160 years, and adopt the /SiZjj/io. 

 aquatica L. = Elopliormi aquaticus Fabr. as the type of the genus 

 Helophorns in the combination I propose adopting. To do so would 

 involve the reversal of the existing application of the names, and 

 require that I should increase the burden of our already too great 

 synonymy. 



For a similar reason I use Helophorus instead of Eloplwrus, though 

 I do not myself approve of the change. Still it was made many years 

 ago and has been universally adopted, and so I continue it in spite of 

 the illegitimate breach of continuity which was introduced a century 

 ago. But I may here say that had the change been recently proposed 

 I should reject it for two reasons, viz. : (1) that it is a change ; and 

 (2) that it is an incorrect change, for the G-reeks did not indicate the 

 aspirate by a letter, and arranged the aspirate and silent letter e in one 

 alphabetical system. 



When I come to treat the individual genera I intend to discuss in 

 detail their characters and relations ; till then the following table will 

 be found adequate for their separation, the characters used in it being 

 selected on account of their convenience rather than of their 

 importance : — 



A2 



