THE GENUS CERCYON. 55 



Whether we take their structure or their habits into consider- 

 ation, the Cercyonidai form the best connecting link between the 

 Hydrophilida and the Silphidce . In our catalogues and manuals 

 they are usually placed immediately before the Staphylinidce ; it 

 must however be admitted, at first sight, that there is a great 

 break between Cryptopleurum and Alitalia, and that the transition 

 to Leptinus and the smaller Silphidce is a much more natural one. 

 This will become more evident if the anatomy of the groups is 

 studied ; in fact the Cercyonidce might well be classed with the 

 Silphidce, but, on the other hand, their affinities to the Hydro- 

 philidcs are so great that it seems hardly possible to remove them 

 from that family. As regards habits they seem to belong to both 

 groups ; one or two species, like C. aquaticus, are almost, if not 

 quite, entirely subaquatic ; others, like C. minutus and Mega- 

 sternum, prefer damp marshy places, but are also found in drier 

 localities ; the majority, however, are dung-feeders, and seem to 

 rejoice in heat and sunshine, like the true Neerophaga. 



The Cercyons are some of our great scavengers. In tropical 

 countries they are very scarce, and in some regions seem to be 

 unrepresented, their places being taken by the Onthophagi and 

 Scarabcei. In summer they swarm all over our country ; there is 

 not a patch or heap of dung or decaying grass or rubbish that is 

 not full of them. One or two species are found on the sea-shore, 

 others are common in fungi ; they may be taken by flinging 

 refuse into water, when they rise to the surface, and they may be 

 found by thousands in winter in flood rubbish. As a rule, 

 however, only about one-half of the species will be found in the 

 ordinary course of collecting; some of them are rare, and many 

 are very hard to distinguish at first. It may therefore be of use 

 to point out certain differences that may serve more easily to 

 separate the species. The chief points to be noticed are 

 size, and shape (whether round, oval, or pointed) ; striation 

 (whether continued to apex of elytra or not) ; punctuation 

 between interstices of elytra, and colour : the latter in some 

 species is very constant, and a true mark ; in others, as in 

 C. pygmceus, by no means reliable : this probably led Stephens 

 into error with regard to many of his species, which are only 

 immature varieties of other forms. 



In Cercyon proper the prosternum ends in one point behind, 

 and the mesosternum is very narrow : in Megastemum and 



