186 



its surface (never as in Rhopcea Verreauxi but) rugulose and 

 pilose only on the lateral parts (or with such sculpture -ex- 

 tending across the middle only as a row of setigerous punc- 

 tures) . 



Now in female Rhopcea (at any rate in the five speeies 

 of which I have seen a female) the spurs of the hind tibiae 

 are of the same shape as in the male and are not (or scarcely) 

 more dilated, the external sexual characters being in the 

 antennae and the hind tarsi, so that if the three genera I 

 have already named were all that had to be reckoned with it 

 would not be of practical importance to decide whether the 

 clypeal or tibial generic structure should be regarded a« the 

 primary character for classification. But there are species 

 which cannot be referred to any of those genera. There is 

 Antitro.gus, with the clypeus of a Rhopcea and spurs of hind 

 tibiae distinctly tending towards the Lepidiota type. 



Next there is the insect which I described as HJtopcea 

 callabonensis, but which on account of the structure of its 

 labrum I do not now think can be included in Rhopcea or 

 any other genus known to be Australian ; it has the clypeus 

 and antennae of a Rhopcea and (although it is a male) the 

 tibial spurs of a female Lepidiota. Pseudholophylla has 

 head and antennae exaggeratedly of the Rhopcea type, but 

 again (though a male) tibial spurs that would befit a female 

 Lepidiota. Another species before me has clypeus and tibial 

 spurs like a Lepidiota, but antennae of a Rhopcea (male with 

 elongate 3rd joint and nabellum of 6 long joints). Neole- 

 pidiota in respect of clypeus, antennae, and tibial spurs agrees 

 (if it is a male) with Lepidiota. 



The conclusion I have reached on full consideration of 

 the data supplied above, and giving much weight to the 

 practical inconvenience of a classification which is inoperative 

 in species whose females are not known, is that for , the 

 Australian species of Lacordaire's "Groupe" "true Melolou- 

 thides" the best character for dividing them primarily into 

 two aggregates is to be found in the structure of the clypeus. 

 This classification brings together into one aggregate Rhopcea, 

 Pseudholophylla, Antitrogus, and a genus characterized in 

 the following pages as Pararhopcea, and places together in a 

 second aggregate Lepidoderma, Lepidiota, Neolepidi&fa, 

 and a genus characterized in the following pages as Para- 

 lepidiota. The former of these primary aggregates is no 

 doubt capable of satisfactory subdivision founded on the 

 spurs of the hind tibiae, but in the absence of definite cer- 

 tainty as to the female of Antitrogus it would be unwise to 

 make use of that character, and I therefore in both aggre- 



