342 Mr. G. J. Arrow on a Contribution to the 



elytra bearing a stridulatory area as in Lvjynis. Legs rather short 

 and stout, the front tibioa bearing three short, equal, and closely set 

 teeth at the outer edge, the four posterior tibia? flattened. Tarsal 

 joints similar. 



1^. Front tarsi thickened and contracted, with the penultimate 

 joint produced into a broad striated plate and the inner claw 

 thickened and feebly cleft. 



Type, CJialepus rostratus, Burm. 



Mr. Linell used the name Fscudorydcs in 1898 for a 

 new genus which he formed for Orydcs ixdayonicus, 

 Waterhouse, but as the same name was adopted in 

 1878 for a very difierent genus of Australian Dynastidas 

 I propose to substitute Neoryctes for the South American 

 genus. 



The Australian genus Adoryphm^us was formed by 

 Mr. Blackburn for a single species of Burmeister's 

 {Dasygnathus Coidoni) and both authors confess ignorance 

 of the male, but the slight tubercle at the back of the 

 head, mentioned in both the very brief descriptions, is 

 distinctive of the male and it therefore seems that both 

 entomologists, looking for some more salient indication of 

 that sex, described the male of this insect as tlie female. 

 As our collection contains a good series of both sexes I 

 may supplement the few published characters by giving 

 the sexual distinctions. The male is parallel-sided and 

 the female ovoid, the body dilating from the clypeus to 

 near the end of the elytra. In addition to the tubercle 

 upon the vertex of the head in the male, the clypeus is 

 shorter, and the prothorax is much shorter and relatively 

 broader. As usual in the Dynastidae the last abdominal 

 segment is more or less triangular in the female and 

 emarginate behind in the male. 



The essential features by which this genus differs from 

 Dasygnathus have not been pointed out, and when the 

 species of this large Australian group are more fully 

 known it may perhaps not be pos-sible to retain it. 



Mr. Blackburn is probably right in supposing Scapancs 

 sotidus, Burm., to be the insect for which he has made 

 another genus, Asemantus, but he is not right in calling 

 it Asemantus suhcT^qualis, Hope. I have ascertained the 

 type of the latter (in the Oxford Museum) to be the same 

 species as that of S. dcprcssus, Hope, described at the 

 same time, and even an individual of ^he same sex ( $ ). 



