502 REVISION OF THE AUSTRALIAN SPECIES OF BOLBOCERAS, 



sharply defined deep narrow sulcus. The female (as regards its 

 distinctively female characters) resembles that of rhinoceros in 

 the transverse carina that tops the retuse front being consider- 

 ably prolonged laterally, and differs from the same b}" the much 

 greater extension of the coarse puncturation on the pronotum 

 and also by the finer of the two systems of puncturation on the 

 retuse part being (on and beyond the lateral parts of the retuse 

 front) very much less fine than it is in rhinoceros. The species 

 differs (non-sexually) from rhinoceros by the character already 

 cited in the elytral sculpture also by the elytral striation 

 stronger and more conspicuously punctulate throughout; and by 

 the base and lateral margins of the prothorax meeting in a 

 narrower curve, so that there is more approach to an angle. 

 The males of all the other species known to me (with hind tibiae 

 multicarinate transversely) have their prothoracic horns either 

 much wider apart from each other or non-bifid at the apex. All 

 the other females (of the same group) known to me have the 

 transverse carina of their pronotum not trisinuate, or much less 

 prolonged laterally, and the retuse front of their pronotum 

 differently sculptured. I am not sure that the female of this 

 insect is not identical with the female which Westwood described 

 as that of B. Reichei (though his description is too brief for 

 certainty), but I am quite satisfied that it is not the female of 

 B. Reichei. 



N. and N.W. Australia. 



B. ARATUM, sp.nov. 



Mas. Latum; robustum; sat nitidum; supra fere glabrum; subtus 

 hirsutum; rufobrunneum; mandibulo sinistro (superne viso) extus 

 pone apicem valde sinuato; capite ante eminentiam frontalem 

 confertim ruguloso, pone banc nitido obsolete punctulato; fronte 

 subhorizontali; eminentia frontali ut cornu subrectum sparsim 

 subtiliter pilosum elevata, hoc (a fronte viso) apicem versus" 

 dilatato et ad apicem bifido (a latere viso) apicem versus sub- 

 ulato; prothorace fortiter transverso, supra postice longitudin- 

 aliter sulcato, fere hevi (partibus lateralibus et sulco longitudinali 

 postico insequaliter varie punctulatis exceptis), antice area magna 



