TlIK ANNALS 



MAUAZINK OF .N.VTUR.VL HISTORY. 



[SEVENTH SERIES.] 

 No. 41. MAY 1001. 



LI. — Remarks on Secondary Sexual Differences in Butelid 

 Coleoptera, with Descriptions of some new Forms. By 

 Gilbert J. Arrow. 



The sexual tliffeience.s of tlie Adoreti have as yet received no 

 attention, although the neglect of them has added to the difK- 

 culty of establishing order in the nomenclature of this much- 

 confused grouj) of Kutelidse, There are a number of extremely 

 similar African species of Adoreius, characterized by a broad 

 clypeus and close grey pubescence, amongst which are a few 

 erect seta?. The separation of these has been found a matter 

 of the greatest difiiculty, but there is a structure found in the 

 males attention to which will, at any rate, very considerably 

 obviate this. Tiie male of Ado)-etus xantliochrous, liar, [lesta- 

 ceus, Fahr.), found in Natal, has the iiind troclianter.-* pro- 

 duced into a long spine, whicii 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. hirte/lus, 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. vestitiis, K( iche (Abyssinia), this sexual structure 

 is represented by a triangnhir ))latc whicli occupies the 



Ann. dt ^faf/. N. //int. >S<-r. 7. \'o/. vii. '26 



