NOTES ON THE GENUS SlOARA. 239 



of either of the eyes (as seen from above), and is about equal to 

 the width of the vertex,* the interior lateral ocular margins 

 being curved outwards from their base, and inwards again 

 towards their apparent apical margin (as viewed from above). 

 Looking at the face {i. e. the reflexed part of the head anterior to 

 the "vertex," and posterior to the clypeus), the eyes appear 

 subtriangular, the interior margins being subparallel to one 

 another, the bases continuous with that part of the head, the 

 exterior margins diverging curvedly from the capital lateral 

 margins, and forming third sides subequal to the interior ocular 

 margins ; apex rounded. The length of the eyes (still viewing 

 the face only) is about equal to the length of the head from the 

 apices of the eyes to the apical margin of the clypeus. The base 

 of the head is somewhat as in S. minutissima (Linn.) ; from the 

 centre of the base the two halves curve downwards at an obtuse 

 angle to one another. Head sordid testaceous ; eyes dark 

 purple-brown ; pronotum light olive-brown (lateral and posterior 

 margins rather broadly sordid luteous), transverse, about twice 

 as wide as long, produced laterally beyond the ocular lateral 

 margins; basal and apical margins very convex, the latter 

 laterally sinuate ; lateral margins very short, slightly diverging 

 posteriorly, about one- seventh (roughly) of the middle breadth 

 of the pronotum. The scutellum is olive-brown, and appears to 

 be divided by a suture into two portions ; I am not, however, 

 acquainted with this structure in any other Sigara, and it may 

 be due to bad preservation and shrinkage ; across the centre of 

 the posterior half of the scutellum is a short transverse dark 

 stripe ; also " metasterno profunde bisinuato, angulis posticis 

 lateralibus elongatis " (Westw.)- Pedes testaceous [I regret I 

 can give no account of the palse] ; intermediate femora about 

 equal to tibife and tarsi together ; unguiculi rather longer than 

 tibiae, tarsi rather longer than unguiculi, and nearly twice as 

 long as tibiae. Hemielytra light olive-brown, obscurely spotted 

 with brown [there appear to be three longitudinal stripes], super- 

 ficially punctured, and sparsely furnished with short yellow 

 hairs. Dorsum of abdomen olive-brown, paler at the margins ; 

 connexivum sordid testaceous. Entire ventral surface tes- 

 taceous. 



I have not been able to detect a strigil in this species, but the 

 insect is so minute that the structure of this would be scarcely 

 visible with a j-in. objective, and the broken and irregular male 

 abdominal segments render the examination of an old and dry 



=■= As explained in Ann, Mag. Nat. Hist. (6), xx. p. 60 (1897), I use 

 "vertex" for the a2:)i}arent apical margin of the head (as seen from above, 

 when the insect is lying flat, venter downwards) ; this margin is therefore 

 really more or less imaginary. Nevertheless it is extremely useful as a 

 diagnostic character in the Notonectidse and Corixidae, to which families its 

 use will be almost entirely restricted — in the sense indicated above. 



