STUDIES IN AUSTRALIAN AQLIATIC HEMIPTERA 



No. I. 

 \W UKRBKR'l' M. HALE, Solth Austkalian Museum. 



Family CORIXIDAE 



Text iig's. 888-350. 



The Corixidac, popularly known as water-boatmoi, ditfcr considcraldy from all 

 other Cryptocerata. The head (tig. 888a), which is about as wide as the thorax, 

 i.s obliquely recurved below, the apex reaching to between the ;interior coxae; the 

 mouth is very short, flattened, and the aperture through which the setaceous 

 mouth parts are protruded is situated abo^-e the tip of the clypeus. The eyes are 

 large and widely separated and the hinder margin overla])s the prothorax. Each 

 pair of legs is of dilferent form and utility. The anterior members are short. 

 in Corixa and sub-genera the tarsus oi- j^ala is extremely modified, particularly 

 in the male, and varies in shape in the ditt'erent species: it consists of a single 

 scoop-like joint, ami seen sideways is generally falcate or cultrate (fig. 338u) ; 

 Ihe lower margin is furnished with two rows of bristly hairs, in one of which 

 roAvs the hairs are very long. On the inner surface of the nude pala are one or 

 more rows of chitinous teeth or ])egs, and it is considered that the characteristic 

 stridulation beneath the water is produced by inibbing this tarsal comb across an 

 area, also covered with tiny pegs, and situated lU'ar the base of the opposite 

 femur. As pointed out by Kirkaldy(M and others, the number of pegs in the 

 comb affords a useful distinguishing specific character. 



In Micronecta the pala of the male terminates in a large flattened claw 

 (fig. 346), which in the female is represented l)y a stiff seta. 



The middle legs are long and attenuated and each terminates in two slender 

 claws; the posterior tarsus is flattened, broadened, and fringed with long hairs. 



The life colouration is a little variable, immature imagos being usually paler. 

 After death some changes are apparent : irregular infuscations, having no relation 

 to the general colour scheme, sometimes appear; in the. descriptions no note is 

 made of inconstant and irrelevant staining; in specimens not fully adult the 

 colour becomes yet paler, while the external parts may shrivel so that the relative 

 proportions are destroyed. 



(1) Kirkaldy, Joiini. Quekott .Micro. Club (2), viii, li»01, p. 35 (Bibliography) and Proe. 

 Hawaiian Eiit. Soc, i, 1906, p. 15. 



