97 



Hydrusa trigonophora, n. sp. PI. v., fig. 7. 



Male and female, 25-35 mm. It differs from H. aperta, Walk., 

 in the smaller size, in the distal spot of hindwings triangular, 

 instead of roundish, the apex of triangle touching basal spot 

 on median vein, and in tuft of male being black laterally. At 

 first, I regarded it as a variety of the preceding ; but have now 

 five specimens taken at Brisbane and Stradbrooke Island, and 

 have seen many others, all of which show the differences to be 

 constant. 



Hydrusa cyanura, Meyr. 



One specimen (Coll. Lucas) ; said to be from Thursday Island, 

 <^ueensland. There is a second specimen in this collection. 



Hydrusa axtitheta, Meyr. 



I saw a type of this species in the Australian Museum, and it 

 seemed to me distinct ; distinguished from H. aperta by the two 

 apical segments being wholly black. Whether a posterior 

 thoracic spot was present I could not decide. No trace of it is 

 discernible, but the pin goes through where it might have been. 



I have received a specimen from Bundaberg, which resembles 

 the type of H. paraula, Meyr., in the Macleay Museum. This 

 may or may not be distinct from the foregoing. The posterior 

 spot is very distinct. 



I have not seen the types of H. anepsia^ Meyr., and H. 

 macroplaca, Meyr., and can therefore express no opinion on these 

 species. 



Hydrusa humeralis, Butl. 



(Journ. Linn. Soc, 1876, 352). 



Male and female 24-30 mm. Antennal pectination in male 

 rather long (2). Head orange, obscurely fuscous between 

 antennae. Antennae black to apex. Thorax black with orange 

 patagia, and a conspicuous posterior orange spot. Abdomen 

 orange, bases of segments broadly blackish ; apical segment in 

 male blackish, with a small dorsal orange spot, in female pale 

 orange. Forewings blackish, spots pale orange, opaque, rather 

 small ; first, roundish or oval ; second, wedge-shaped, apex 

 anterior, obtuse ; third, irregular-oblong or sub-triangular ; 

 fourth, elongate, sometimes surmounted by an additional dot ; 

 connecting spot absent ; fifth, roundish or oval, evenly bisected 

 by a black vein. Hindwings black, with spots large and con- 

 fluent, somewhat constricted at point of union. 



Distinguished by long antennal pectinations of male, con- 

 fluence of spots of hindwings, and especially by the orange 

 patagia. 



