98 rOctober, 



portion roughly puueture J ; middle keel slight ; tubercles of the 

 hinder angles small but distinct ; under-curved sides, below the 

 hinder angles only, with a yellow, hindwardly widened streak. 

 'Elytra blue-black, apex fuscous, nerves with golden-yellow scale- 

 hairs. Sternum, especially at the sides, with a silvery gloss, in the 

 ? brassy, but in both sexes grey or blackish next the pronotum ; 

 ^rosternum, yellow, black in the middle ; metasternum posteriorly, 

 in the ^ , with a very small tubercle ; sheaths of all the coxae 

 unkeeled, black, 2nd pair on the middle and at the inner side with 

 a silvery streak. JLe^s — Cox(S black above, yellow beneath ; fulcra 

 yellow, 1st pair with a black central streak ; thighs, 1st pair black, 

 yellow inwardly at the base, 2nd and 3rd pairs black-brown above, 

 yellow-brown beneath ; tihice and tarsi all black. 

 Abdomen — beneath with a silvery gloss, in the ? brassy at the sides ; 

 in the (J , on the 6th segment, in the middle, two short, stout, obtuse, 

 forwardly directed, black, spinous processes ; posterior margin in 

 the middle with a deep, rounded excision, on each side of which 

 the colour is brown ; in the ? the posterior margin of the 6th 

 segment is raised, brownish in the middle, and slightly and 

 regularly excavate. Genital segments, in the ^ long, on the 

 upper-side the 1st long, quadrangular, projects much beyond the 

 points of the connexiva, black, posterior angles brown ; 2nd very 

 short, obtuse ; beneath, the 1st posteriorly almost squarely cut out, 

 the middle projecting a little on to the 2nd, the sides receding 

 gradually to a point ; the 2nd long, cylindrical, rounded behind, 

 black, brown posteriorly, covered with a whitish gloss. In the $ 

 beneath, short, the 1st yellowish, trapezoidal, tapering posteriorly, 

 with a deep rounded furrow across the base ; 2nd very small. 



Length 3| — 3f lines. 



Most like S. lacustris, but easily distinguished by being always 

 black beneath ; the ^ by the processes on the 6th abdominal segment ; 

 the $ by the furrow on the 1st genital segment. 



Hitherto not common, or overlooked. Taken at Lee and Gravesend, 

 on still water, in April and May. 



CRTPTOCERATA. 

 Section 5. — Cobixina. 



Family 1. — Coeixid^. 



Genus 1. — Corixa, GeofFr. 



Species 9*. — Coeixa pe^usta. 



ComsA PE-JiuSTA, Fieh., Syn. Coris No. 14 (1848) ; Spec. Coris. 28, 30, 



