G-10 Mr. E. Saunders' S7/noj)sis nf 



distinct dorsal carina to the thorax; the posterior les^s 

 shorter, tlie tibias and tarsi together not being so long as 

 the femora; first joint of the tarsi shorter than in gibhl- 

 fern. 



Length 4 — 4^ lines. 



Common on water. 



9. odontogaster, Zett. Fig. H.-Schff. Wanz. Ins. ix. 



pi. ccci. fig. 931. 



Very like lacustris, but if anything rather smaller ; 

 the front tibifc black, except at their extreme l)ase, whieli 

 is red; posterior legs shorter; the $ at once distinguish- 

 able by the two teeth that project from the sixth ab- 

 dominal segment beneath. 



Length 3^ — 4 lines. 



Not rare ; Reigate, Gravesend, Lee, Esher, &c. 



10. argentata, Schum. Fig. H.-Schff. AVanz. Ins. ix; 

 pi. ccci. fig. 932. 



The smallest of our species, very like the two preceding, 

 but distinguishable by the very short posterior tibia3 and 

 tarsi, which together are not nearly so long as the femora ; 

 it has also rather a brighter and more silveiy appearance, 

 there being often some silvery scales at the base of the 

 thorax. 



Length 3 — 4 lines. 



Not common ; Esher, Keigate, &c., &c. 



MiCRCVELIA. 



1. pygman, Duf. Fig. Dougl. & Scott, Brit. Hem. 

 pi. xix. fig. 3. 



Very small, black ; head with a line on each side, on 

 the inner margin of the eye, silvery. Thorax very wide 

 behind, Avith the angles produced and rounded ; callosities 

 and the front margin Avith a band of silvery hairs. Elytra 

 grey, Avith paler grey or Avhite markings. Legs Avith the 

 Icmora at the base pale. Antennee pale at the base of the 

 first joint. 



Length | line. 



Not rare in streams, &c.; generally undcAeloped. 



Undeveloped form, AAathout elytra and Avith the thorax 

 not so Avidened posteriorly. 



