THE ANNALS 
MAGAZINE OF NATURAL HISTORY. 
(SEVENTH SERIES. ] 
No. 41. MAY 1901. 
> -— —— 
LI.—Remarks on Secondary Sexual Differences tr Rutelid 
Coleoptera, with Descriptions of some new Forms. By 
GiLBerT J. ARROW. 
THE sexual differences of the Adorete have as yet received no 
attention, although the neglect of them has added to the diffi- 
culty of establishing order in the nomenclature of this much- 
confused group of Rutelidee. ‘There are a number of extremely 
similar African species of Adoretus, characterized by a broad 
clypeus and close grey pubescence, amongst which are a few 
erect sete. The separation of these has been found a matter 
of the greatest difficulty, but there is a structure found in the 
males attention to which will, at any rate, very considerably 
obviate this. The male of Adoretus vanthochrous, Har. (testa- 
ceus, Fahr.), found in Natal, has the hind trochanters_pro- 
duced into a long spine, which has been described as a specific 
character. It seems to have been overlooked that it occurs in 
only one sex. 
The male of the West-African A. hirtellus, Lap., has a 
similar long spine, but consisting in this case of a sharp pro- 
jection from the femur. It is represented in the female by a 
slight and not acute prominence. 
In A. vestitus, Reiche (Abyssinia), this sexual structure 
iS represented by a triangular plate which occupies the 
Ann. &: Mag: N. Hist. Ser. 7. Vol. vii. 28 
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