Hale — Aquatic Hemiptera 



325 



111 autuiun ( Ajiril and May) of li)21 this species w..s common in the Torrens 

 Kivei- at Adelaide, at whicli time the water was at a coniparativel}^ low level; 

 iai-vae and pnpae (j)), as well as ima!:i()s, were present in considerable numbers. 

 In August of the same year, when the rixcr had a<«'ain somewhat subsided after 

 Ihe winter rains, huiulreds of sjx'ciiiiens were taken, all being fully adult. Mud 

 adhered plentifully to the backs of very many of Hiein, and in one instance a 

 branched alga was attached to and gi-owing ])rofusely on the wing covers of the 

 living bug. Epiphytic diatoms were associated with the alga, wbich was deter- 

 mined by Mr. L. J. Millar as a species of Chid oph ova, which has also been taken 

 from the eara])aees of Murray River tortoises. The presence of mud and living 

 vegetation iiidieates that the insects ai-e dormant during the wint(n-. J. W. 

 l)ougias(") observed English Corixar in the spring besmeared with mud, and 

 suggests that the l)ngs are buried in the riv(n--bed throughout the winter months. 

 Jf, however, they merely remained inactive and clinging to weeds and stones, 

 they Avould become similarly coated, for sediment would deposit evenly on the 

 head, pronotum, and hemelytra. 



MICRONECTA ROBUSTA sp. nov. 



6 Head greenish oehraceons, Avith a longitudinal, median testaceous line; 

 hinder margin darkened and with a central, dark l)rown tubercle; length little 

 more than half the width at base between eyes, rather shorter than the pronotum. 

 Pronotum dark greyish-brown ; width between humeral angles much more than 

 twice medial length ; shining, smooth, except for very faint transverse scratches ; 

 lateral margins a little oblique ; angles obtuse. Scutellum testaceous. Hemelytra 

 greyish-brown, paler at base, darkened apieally ; punctured ; costal margins 

 oehraceons, with two linear, blackish markings; clavus with somewhat broken 



Fi-. 347. . 

 M icroticctii robiista . 



Fig. 348. 

 Micronccta gracilis . 



I'ig. 349. 

 Micronccta virgufa. 



(T) Douglas, Eiit. :\[ontli. Mag., iii, 186G, p. 27. 



