264 



gin, whereas it should stand among those having a fine raised 

 margin along the base (Group V.), where its place will be be- 

 side, Zietzi, Blackb., and nitidior, Blackb. (page 271), from 

 both of which it differs by the presence of a humeral red spot 

 on each elytron. The punctures of its elytral interstices are 

 notably stronger than those of 0. Zietzi, and much less coarse 

 than those of 0. 7iiticlior, 



SERICIDES. 



DiPHUCEPHALA. 



This extensive genus, no doubt on account of its species 

 being for the most part of brilliant colourings, and many of 

 them very abundant, contains numerous species whose so- 

 called descriptions are scarcely worthy o^ being called descrip- 

 tions at all. Consequently a really reliable monograph of its 

 species is practically unattainable. On this ground, I have 

 always hitherto omitted it when dealing with allied genera. 

 As, however, the types are so scattered over the world that 

 it is not likely one author can be in a much better position 

 than another for solving the many enigmas of the genus, . 

 only prospect of eventually reducing it to order seems to lie 

 in someone making the best attempt he can at a revision of its 

 contents, and so giving an opportunity for those v.4io have 

 access to individual types in isolated collections to confirm or 

 correct with authority his identifications. It is with this idea 

 that I offer the following notes on the genus, and I hope to 

 be able at least to render it possible to identify the insects 

 to which the specitic names are applied in a memoir that, if 

 in places needing correction, at any rate discusses all the 

 existing names in a connected series. I have had the advan- 

 tage of examining nearly all the types of Sir W. Macleay's 

 species, and some of his identifications of species described in 

 Europe, and therefore probably have at command as much 

 profitable material for the work as anyone else could have. 



The species of Diphvcephala have been described under 

 56 names, the earliest description being. I think, that of 7). 

 colafipidoides, Schonh., published about the year 1806. The 

 only treatises that I know dealinsf with the species collec- 

 tively are those of Mr. G. R. Waterhouse (A.D. 1835), dealing 

 with 16 species, and Sir W. Macleay (A.D. 1886) dealing with 

 43 species. The former of those treatises is, of course, obso- 

 lete, and the latter merely Sfives descriptions (many of them 

 very insufficient) of the species known to the author, and 

 which are divided into five e^roups, but not further classified. 

 Burmeister, it is true, in 1855, included a synopsis of the 

 genus in his ''Handbuch der Entomologie," but it contained 

 only a slight grouping of the species, and was little more than 



