400 Records of the S.A. Museum 



, Sub-Family Notonectinae. 

 ANISOPS Spinola. 



Anisops Spin., Ess. Hem., 1837, p. 58; Fieb., Rhynchotogr., 1851, p. 57; Stal., 

 Hem. Afr., iii, 1865, p. 191; Kirk., Wieii. ent. Zeit., xxiii, l'J04, p. 111. 

 Type, A. niveus Fabricius. 

 This is the predominant Notonectid genus in Australia. The form is slender 



and the last antennal segment is longer than the penultimate segment, a condition 



reversed ni Notonecta. When in the water the bugs appear silvery, with the 



venter dark. 



KEY TO AUSTRALJAN SPECIES OP ANISOF.S. 



a. Head large, as wide, or almost as wide, as pronotum. 



b. Form slender; eyes of male almost touching at base of 

 head. 



c. Male with a cephalic horn fieberi. 



cc. Male without cephalic horn . . . dor is. 



bb. Form robust; eyes well separated at base of head, 

 d. Synthlipsis narrower than vertex. 



e. Pronotum of male long, a little wider than its 



length hyperion. 



ee. Pronotum sliort, twice as wide as long . . . . ocularis. 



dd. Synthlipsis about same width as vertex endymion. 



aa. Head small, distinctly narrower than pronotum. 



f. S.ynthlipsis less than half vertex (jratus. 



ff. Synthlipsis more than half vertex. 



g. Posterior margin of pronotum concavely incised ; 



over 10 mm. in length st(di. 



gg. Posterior margin of pronotum convex ; less than 



10 mm. in length c(dcaratus. 



I know A. endymion only from the original description; Kirkaldy does not 

 mention the comparative width of the head, so that its jiosition in the above key is 

 tentative. If it possesses a small head it should be placed with A. stali and A. 

 calcaratHs, from both of which it differs in the wider sjaithlipsis. 



ANISOPS FIEBERI Kirkaldy. 



Anisops flehcri Kirk., Entomologist, 1901, p. 5 & AVicn. ent. Zeit., xxiii, 1904, 



p. 116. 

 Anisops niveus Fieb., Rhynchotogr., 1851, p. 60 (not Fabr.). 



