( 479 ) 



XV. On the Characters and Relationships of the less-hnown 

 groups of Lamellicorn Coleoptera, ^oith descriptions 

 of new spiecies of Hybosorinae, etc. By Gilbert J. 

 Arrow, F.E.S. 



[Read October Gtli, 1909.] 



In the Lamellicornia , as in other groups of animals, the 

 forms which throAV most light upon the problems of origin 

 and phylogeny are those which are least numerous and 

 obtrusive, and which, unless they happen to be individually 

 rare, have no special attraction for the general collector. 

 The super-family Zamellicornicc is so multitudinous, and 

 contains such an abundance of forms which attract atten- 

 tion by their beauty, size, or strangeness of aspect, that the 

 groups in which these qualities are deficient have been 

 very generally neglected, and the classification of some of 

 the most primitive and interesting families has remained 

 practically unstudied since Erichson, in 1848, published 

 the most important contribution which has been made to 

 the subject of Lamellicorn classification. 



Erichson's division of all the Scarabaeidae into two 

 great series, according as the posterior abdominal spiracles 

 are situated in the dorsal part of the ventral segments 

 (Fleurosticti) or in the membranes connecting the dorsal 

 and ventral segments {Laparosticti), has been universally 

 adopted, although his criterion has never been actually 

 applied to some of the minor groups, and the position and 

 relations of several have been accepted as they were 

 assigned by him, although it is precisely in regard to these 

 that the scheme detailed in his " Insecten Deutschlands " 

 was least carefully elaborated. Some of the groups do 

 not belong to the German fauna, and in any case the 

 forms known to Erichson were so few that it was not 

 possible to ascertain what features were fixed and funda- 

 mental, and what characteristic only of species or genera. 

 In endeavouring to distinguish these groups by reference 

 to the formulae devised by Erichson and adopted by his 

 successors, I have found these formulae of little use and 

 have been obliged to investigate their mutual relation- 



TRANS. ENT. SOC. LOND. 1909. — PART IV. (DEC.) 



