41 



PLATYDEMA. 



A female example of this genus was found at the Barrow 

 Jiange. It does not seem to appertain to any described species, 

 but it would not be well to describe it witliout having seen its 

 male. 



PTEKOriELJ.US. 



P. nitidmsculus, Macl. ? This species is known to me only by the 

 description. The example taken by Mr. Helms at Victoria 

 Spring is smaller than the type (long., 4i 1.), but otherwise 

 agrees with Sir W. Macleay's description. 



r. Indhitus, Pasc. Nilpena, or thereabouts. 



IIELiEUS. 



//. aridu.% sp. nov. Late ovalis ; sul)nitidus ; glaber ; niger, 

 lateribus foliaceis vix rufescentibus, corpore subtus pedibus 

 antennisque brunnescentibus ; prothoracis lateribus foliaceis 

 obsolete minus crebre granulatis, disco cornu valido conico 

 armato ; elytrorum disco sat crebre sat fortiter punctulato 

 et granulis sat fortibus seriatim instructo, lateribus foliaceis 

 liaiid punctulatis confuse sat fortiter granulatis, margine 

 reflexo verticali obscure ruguloso ; subtus elytrorum marg- 

 inibus foliaceis minus crebre obsolete punctulatis. Long., 

 151^161 1. ; lat., 9i— lOA 1. 

 The granules on the elytra are variable ; in some examples they 

 form seven well-defined rows confused only near the front of the 

 elytra, in others some of these rows are interrupted, in others 

 tliey are confused witli granules placed on the interstices, so that 

 there seem to be a large number of ill-defined rows. The granules 

 of the row next the suture on either side are very closely placed 

 in front, where they form a quasi-costa. This species seems to 

 me to be best distinguished by the perfectly vertical wide reflexed 

 margin of both pro'thorax and elytra which is opaque, obscurely 

 rugulose, and almost devoid of any continuous longitudinal 

 furrow ; viewed from the side it is seen to be of almost perfectly 

 even width from the front angles of the pro thorax almost to the 

 apex of the elytra. A study of this external (more or less erect) 

 margin of the prothorax and elytra appears to me to yield very 

 valuable results in the determination of the species of the ex- 

 tremely difficult group which Sir W. Macleay made the fiirst 

 section of Ilehms. The present species is also characterised by 

 the (juite strongly punctulate disc of its elytra in contrast with 

 tiie impunctulate foliaceous margins. In some examples the 

 apical ventral segment is much more acuminate behind than in 

 others ; probably this difl'erence is sexual. 



It is possible that this insect is identical with that which Sir 

 W. Macleay regarded as JJ. princeps, Hope, but if so I am con- 



