( 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.)
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