On the British Species o/Haliplus. 97 



IV On the British Species of Haliplus, LatreiUe, related 

 to Hahplus ruficolhs, J>e Oeer, tvith some Bemarks upon 

 H. fulvicollis, Enchson, and H. furcafus, Seidlitz. By 



^^''t^qV f^'^J^o^'?''^'^''''' ^^•^- (0-^o»- ^^ Cantab.), 

 . -p rV ^\'^-^-' Lecturer in Entomolon^y in the Depart- 

 ment ot Zoologj^, University of Cambridge. 



[Plates VII. & Vm.] 



The group of species which I have referred to as beino- 

 related to Haliplus ruficollis, De G., includes seven British 

 forms, of which only three were known in our islands until a 

 tew years ago. The group is a very difficult one, as is evi- 

 denced by the fact that three attempts have been made upon 

 it, without, liowever, altogether satisfactory results. 



The first attempt was made by Gerliardt (8 and 9) *, who 

 separated six mid-European species, relying chiefly upon the 

 sculpture and upon the lineation and markings of tlie elytra. 

 He also divided the species into two groups, according as 

 tiie prosternum was grooved or flat. Three years later, 

 Wehiicke (22) drew up another analytical table in which he 

 mckided eleven species, but he relied upon the same characters 

 as (jerhardt had done. 



Four years ago Edwards (5) distinguished the Britannic 

 species ^ot the group, using, in addition to tlie previous 

 authors characters, the form of the ffideagus and its accessory 

 Jobes. Until Ins paper appeared five species had been 

 passing with British coleopterists under //. ruficollis and 

 n.Jiuviatihs, and of these Edwards separated all except one. 

 Had he taken more advantage of his discovery of the adeao-al 

 character— which is the only absolutely reliable specffic 

 one,— he might have been saved from a number of errors 

 into which he felh However, he did not use it for distin- 

 guishing all his species, but relied rather upon other characters 

 which are somewhat variable. Several statements made by 

 him are contrary to the observations of the earlier authors 

 and in attempting to work out my material with the aid of 

 his paper I found it unsatisfactory. 



His description of the elytral punctuiation of the female of 

 B. rufwolhs diff-ers, as to the extent of that puncturation, 

 trom Gerhardt s, who first observed it, and from tliat of all 

 tlie succeeding authors (most of whom probably copied 

 berliardt), and Edwards explains this by assuming that they 



* See Bibliograpliy, p. 122. 

 Ann. <& Mag. N. Hist. Ser. 8. Vol xv. 7 



