Beetles of the family Rutelidm. 267 



often found in the females and the red in the males. He 

 may have been misled by the examination of an aberrant 

 female, for one of many which I have examined is gynan- 

 dromorphous, showing the black coloration proper to the 

 males; or, as he nowhere mentions the principal sexual 

 characters of the genus, it is possible that he was entirely 

 mistaken as to the sexes of his specimens. These charac- 

 ters have not been fully pointed out by subsequent mono- 

 graphers, so that it may be well to describe them here. 



The tibiae, tarsi and claws of the male are all consider- 

 ably stouter than in the female, and the teeth on the front 

 tibiae are short, sharp and conical, whereas in the female 

 the anterior one is produced and convex. The outer claw 

 of the anterior tarsus in the male forms a flattened plate 

 and has a sharp slender tooth near its extremity; that of 

 the middle tarsus is very long and undivided. In the 

 other sex both are simply bifid. The antennal club is 

 perceptibly longer in the male and the pygidium is visible 

 from beneath. In the female the pygidium is only visible 

 from above, the junction with the last ventral segment 

 being at the extremity of the body and not ventral. 



Another and closely related example in this genus is 

 Popillia flavotrabeata, Thoms., of which only the female 

 appears to have been as yet described. This is an elongate 

 golden- or bronzy-green insect with yellow margins to the 

 thorax and an oblique band of the same colour on each 

 elytron, which however is liable to disappear. The male 

 exactly corresponds to that of P. rufipes, except that the 

 thorax retains the coloration of the female, the elytra in 

 fully mature specimens being shining black. The legs in 

 both species are paler and non-metallic in the male. It is 

 remarkable that of this species also a single female speci- 

 men in the British Museum has the male coloration, 

 although a trace still remains of the pale elytral streak 

 peculiar to its own sex. 



The female of this species is also P. lacertosaoi Candeze. 

 Herr Kolbe in his monograph of the African species of 

 Popillia suggests the identity of this with Thomson's 

 species, and of this I have no doubt. 



It will be seen that the sexual differences in the struc- 

 ture of the claws are confined to the African species of the 

 cylindrical testaceous group of Anomalas, whereas colour 

 dimorphism occurs in species from all parts of the world 

 representing widely separated sections of the genus. In 

 every case of the latter type the distinction consists not in 



