Mr. J. S. Baly on new Genera and Species of Phytophaga. 439 



species some one or other of these diagnostic marks are fre- 

 quently absent. The greatest amount of divergence from the 

 typical form occurs in the grooves of the thorax and the striae 

 of the elytra : thus in A. bifrons, Erichson's type (which, ac- 

 cording to my views, is an aberrant form of the genus), the basal 

 grooves ar^ only represented by faint notches, and the transverse 

 sulcation is entirely absent ; the striae of the elytra in the same 

 species are also visible only near their extreme lateral border. 

 In A. nitida, Waterhouse, the thorax is entirely free from im- 

 pressions, whilst the striae of the elytra are only to be seen on 

 the hinder half of the disk ; again, in A. ruffulosa the striae are 

 entirely obsolete, the general surface of the elytra being irregu- 

 larly punctured and rugulose. Between these extremes and the 

 typical species every degree of variation exists ; it will therefore 

 be seen that any attempt to divide these insects into genera, 

 dependent on the presence or absence of the grooves of the 

 thorax or the striae of the elytra, is utterly futile, the arrange- 

 ment of Illiger, so useful and complete in reference to European 

 genera, breaking down entirely when applied to exotic forms. 



Tabular Arrangement of the Australian Species, 



I. Corpus fulvum. 



A. Elytra distincte punctato-ttriata variegata, Waterh. 



B. Elytra minus distincte punctato-striata, striis in- 



terdum obsoletis. 



a. Corpus brcviter ovatum ovata, Waterh. 



b. Corpus anguste ovatum attenuata*, Waterh. 



II. Corpus mctnllicum aut uignitn. 



A. Thorax et elytra lac^-ia, non rugulosa. 



A. .\utcnnffil3reve8, subincrassata; crajfieomit, Waterh. 



B. .\ntenna: longiores, tilifomies. 



a. Impressiones basales thoracis obsoleta:. 



• Thorax metalUcus nitida, Waterh. 



* Thorax rufo-fulvus fulvicolUs, n. sp. 



b. Impressioiiea basales thoracis semper plus 



minusve distincta:. 

 t Sulcus transreraus thoracis obnoletus. 



* Corpus nigro-piceum bifrons, Erichs. 



♦ Corpus meulhcum femorata, n. sp. 



ti- Sulcus transversus semper plus minusve 



distiuctus. 



• Thorax fulvus bicolor, Waterh. 



* Thorax metallicus. 



X Sulcus curvatus faciei medio intemiptus . . consuta. Germ. 

 Xt Sulcus curvatus faciei integer. 



§ Corpus elongato-ovatura Chrysis, Oliv. 



§§ Corpus breviter ovatum, crassum. 



II Abdominis apex fulvus MacLeayi, n. sp. 



II II Abdominis apex basi coucolor Lownei, n. sp. 



U. Thorax et el}tra rugu losa ruyulosa, n. sp. 



♦ Mr. Waterhouse has described the sexes of this species under two 



