644 ]Mr. E. Saunders' Synopsis of 



thorax shining, pale ochraceous or greenish. Scutellnm 

 large, black, finely and shortly gold pubescent. Elytra 

 cither pale, more or less spotted with black-brown, or 

 glaucous black, with two basal streaks pale ; in the var. 

 maculata the black-brown spots sometimes almost cover 

 the whole elytra. Legs pale, the intermediate tibiie 

 toothed beneath. 



Length 7 — 8 lines. 



Common everywhere in ponds, &c. 



Plea. 



1. minidissima, Fab. Fig. Dougl. & Scott, Brit. Hem. 

 pi. XX. fig. 3. 



Very small, short and convex, pale yelloAvish-whitc ; 

 surface reticulated. Head wider than the thorax in front, 

 with a brown line down the centre; apices of the tarsi 

 brown. 



Length 1 line. 



Common in ponds, &c. 



CORIXIDJE. 



I. Scutellum not visible. 



a. Thorax with transverse lines . . . . . . . . Corixa. 



b. Thorax without transverse lines . . . . . • Cymatia, 



II. Scutellum visible .. .. .. .. .. .. Sigara. 



CORIXA. 



I. Thorax and elytra entirely smooth, not rastrate; 

 asymmetry to left side in $ . 



A. Lai'ger, thorax with 16 or more lines .. Geoffroyi. 



A A. Smaller, thorax with 12 — 14 lines. 



a. Claws of intermediate legs longer than 



tarsi .. .. .. .. .. atfinis. 



b. Claws of intermediate legs shorter than 



tarsi .. .. .. .. .. Panzeri. 



II. Thorax and elytra more or less rastrate; asymmetry 

 to right side in $ . 



A. Posterior metatarsi conspicuously marked 



with black at the apex ; $ without strigil. 



B. Clavus with longitudinal lines.. .. .. Bold'd. 



BB. Clavus with transvcr.se lines. 



C. Markings of elytra clearly defined. 



D. Spot on hind tarsus large and quadrate, or 



nearly .so . . . . . . . . . . jirccnsta. 



IJD. Spot on hind t.nrsus small and triangular, 

 placed at the inner apical angle. 



