24 ON THE GENUS CHALCOCYBEBUS. 



orbital wrinkles ; the basal dot on the fourth spatium is 

 wanting in both his specimens (cf and 9). 



Ch, nitcns Voll. The type of this species is a female 

 of 13,5 mm. length (without the rostrum), and in colour 

 it is like the bluish variety of Chrysomela menthastri. Not 

 a single female among the Papuan specimens agrees abso- 

 lutely with the type, and, since the male of the Waigeou- 

 species is still unknown , I prefer to indicate provisionally ') 

 the New Guinea-form by a subspecific name. The only 

 plastic difference between nitens type and papuanus consists 

 in the more erect and inward-curving dorsal spines of the 

 latter, so that an imagined prolongation of its axis hardly 

 touches the margin of the opposite elytron (when seen 

 from behind) , whilst in the typical nitens the axis evidently 

 passes through the opposite elytron. The male of Ch. 

 nitens papuanus {Ch. hamatus Faust in coll.) has the an- 

 terior femora strongly mucronate near the apex and ordi- 

 narily blue shining elytra, like Diacanthus aeneus, var. 

 coeruleus Schilsky. The papuanus var. auratus shows that 

 the form and direction of the dorsal spines have no great 

 value from a systematical point of view. 



Ch. splenflidus Blackb. is a quite aberrant form in 

 virtue of its strong sculpture, having an intermediate po- 

 sition between the genus Chalcocyhebus and Eurhynchus, 

 but, since it agrees with the characteristics of Chalcocy- 

 hehus given by Mr. J. Faust , it must be referred to this 

 genus. 



Royal Zoological Museum, 

 Dresden, April 1896. 



1) Whilst the typical bispinosus inhabits Waigeou and New Guinea, it is 

 probable that the specimens of Cfi. nitens from both localities belong to the 

 same species. 



Notes from the Leyden Museum , "Vol. XVIII. 



