126 



Shp.j only by its less metallic tone of coloring and the absence of 

 a testaceous spot on its elytra. The size he assigns to it is 

 slightly larger than that Dr. Sharp mentions as the size of 

 (Buescens. Presumably Mr. Lea has, since the time when he 

 described P. subanescens, taken additional specimens, as the 

 example sent to me (from Beverley, W.A.) has a testaceous spot 

 oa each elytron similar to that of cenescens. Hence the differences 

 mentioned are reduced to somewhat larger size and less distinctly 

 seneous coloring. Nevertheless, if my specimen of csnescens is 

 rightly named (as I think it is), I take Mr. Lea's species to be a 

 valid one as it is (my specimens of both are females) of consider- 

 ably different form, having more rounded sides and being dis- 

 tinctly less blunt at the hind apex. P. suhcenescens belongs to 

 Dr. Sharp's first group of Platynectes, and is very distinct from 

 all its described Australian congeners except cenescens. 



GYRINID^. 



MACROGYRUS. 



M. fortissimus, sp. nov. Fem. Late ovalis ; minus convexus ; 

 nitidus ; supra nigroseneus vix cuprascens ; subtus piceus, 

 palpis pedibus abdomineque obscure rufescentibus ; supra 

 subtilissime coriaceus ; elytris striolis minimis transversis 

 subtilissime impressis, obsoletissime regulariter striatis, inter- 

 stitiis vix manifeste (alternis quam cetera nonnihil magis 

 distincte) convexis, ad apicem leviter dehiscentibus late sub- 

 truncatis, angulis externo bene definito sed nullo modo acuto 

 (mediano nullo) suturali subrotundato; tibiis anticis apicem 

 versus modice latis, angulo externo apicali obtuso sed extror- 

 sum manifeste prominentibus ; pygidio sat dense fulvo- 

 pubescenti. Long., 8^ 1.; lat., 4f . 

 A large species (not smaller than M. rivularis, Clk.), at once 

 distinguishable from all its described Australian congeners 

 except M. Howitti, Clk., by the absence of longitudinal elytral 

 sulci. It differs from the description of M. Hotvitti, inter alia, 

 by its large size, its extremely wide form, the absence of metallic 

 blue and green coloring from its lateral margins and the presence 

 of quite distinct (though very faint) stride on its elytra. Com- 

 pared with specimens (female; rom Tasmania which agree well 

 with the description of M. Howitti the present species differs 

 (apart from the distinctions noted above) by the finer and closer 

 transverse striolation of its elytra and by the striolse appearing 

 very closely and finely zigzagged, — an appearance that seems 

 (under a very strong lens) to be caused by the presence of 

 minute punctures interrupting their outline. The elytral quasi- 

 strise are nine in number, and the external striae are scarcely more 

 distinct than those near the suture. The apex of the elytra 



