198 



found plentifully by Mr. Griffith flying in the evening at 

 Henley Beach, near Adelaide. The Antitrogi are compara- 

 tively large Melolonthides, not closely resembling in facies 

 any others known to me, but perhaps most like the less- 

 elongate species of Rhopcea, which indeed are, in my opinion,, 

 their closest allies. Brenske regarded them as a subgenus of 

 Lepidiota, but in this I cannot follow him. I cannot find 

 any statement of his reasons for this assignment but con- 

 jecture that it was founded on the number of joints in the 

 antennal flabellum (to which I am convinced he attributed 

 too much importance) and on the structure of the spurs of 

 the hind tibiae in the female. This latter character is no 

 doubt of importance, but I doubt whether Brenske can have 

 seen a female, which sex was not known to Burmeister, the 

 author of the genus and of its only as yet described species ;: 

 and as Brenske refers only to that species, and refers only to 

 Burmeister's treatment of that species (which was certainly 

 founded on a male), it seems quite possible that he had seen? 

 only the original type. As a fact the structure of the spurs 

 of the hind tibiae in the female is much more of the Rhopcea 

 type than of the Lepidiota type. The inner spur of that sex 

 is a little more definitely enlarged as compared with that of 

 the male than in Rhopcea, and is blunted at the apex (pro- 

 bably indicating that the place of Antitrogus is between 

 Rhopcea and Lepidiota), but it has no tendency towards the" 

 "spoon" shape which Brenske considers (so far as my know- 

 ledge of the genus extends, correctly) characteristic of 

 Lepidiota, and, moreover, is not dilated from the base 

 upward. The sculpture and vestiture of the front declivous 

 face of the clypeus is absolutely of the Rhopcea type, a char- 

 acter which — as I have already indicated — I regard as of first 

 importance. When to these considerations are added the 

 fact that Antitrogus in facies considerably resembles Rhopcea 

 and is particularly unlike a typical Lepidiota, and the f act- 

 that its vestiture (at any rate that of all the species I have 

 seen) is entirely pilose (not squamiferous), it really seems to 

 me a very clear case that Brenske misplaced it. 



Burmeister made Antitrogus a subgenus of Rhizotrogus f . 

 and, of course, Brenske is right in disputing that assignment. 

 It is no doubt very much nearer Lepidiota than Rhizotrogus. 



The three species known to me of the genus are 

 extremely close, inter se, and seem to be very variable in 

 colour and in degree of pruinosity. I find, however, very 

 little variation among the individuals of the only large batch 

 of specimens that I have seen as taken in company, and there- 

 fore I think that the differences of colour and iridescence in: 

 the single individuals (or in some cases two) that I have seem 



