NEPID^E. 583 



Yellowish-brown, smooth. 



Eyes with a brown spot in the middle. Legs concolorous with 

 the body, the serration of the groove on the anterior thighs and the 

 inner side of the anterior tibiae, black. 



Abdomen above, exclusive of the connexivum, red. 



Length (exclusive of spiracular filaments), 18 lines ; filaments 15 

 lines. 



Not common. In stagnant water, mostly at the bottom, as the in- 

 sects swim badly. "Wandsworth Common ; Hammersmith Marshes, 



FAMILY 2. NEPIDJE, 



Genus 1. NEPA, Lin. 

 Long-oval, very flat and thin. 



Head short, obtuse. Antennae ; 1st joint subglobose ; 2nd of 

 equal length, produced laterally at the end into a falcate process ; 

 3rd of similar form, nearly as long, incumbent on the 2nd. Eyes 

 seen from the side reniform, from above oval, convex, prominent. 

 Hostrum almost vertical, conical ; 1st joint annular, 2nd tumid in 

 the middle beneath, 3rd obconic. 



Thorax. Pronotum broad, trapezoidal ; anterior margin much 

 longer than the width of the head ; anterior angles broadly rounded, 

 the middle deeply cut out for the reception of the head ; disk, the 

 1st f rds posteriorly defined by a sharp, linear, transverse incision, 

 deepest towards the sides ; the side margins narrowly, sharply de- 

 fined ; the middle longitudinally depressed, with a large, longitu- 

 dinal callosity on each side of it, the rest of the anterior portion 

 uneven ; the posterior 3rd even, dilated, the sides incrassated, the 

 callosity on the inner side anteriorly with a deep, rounded, foveate 

 channel ; posterior margin slightly concave. Scutellum large, trian- 

 gular ; basal angles with a long depression, but the side margins 

 raised. Elytra coriaceous and reticulated throughout ; Clavus long, 

 irregularly triangular, with 1 raised nerve ; Corium with 2 scarcely 

 perceptible long nerves and very fine reticulations ; Embolium long, 

 parallel, indistinct on the upper side ; Membrane short, indistinctly 

 separated from the corium, rather thinner, irregularly reticulated. 

 Wings with 4 long nerves, but not reaching the posterior margin ; 

 the 1st 3 united posteriorly, forming 2 long cells. Sternum ; Pro- 



