382 INSECT TRANSFORMATIONS. 



swimming against small streams, and apparently more 

 for the purpose of maintaining their place than of 

 making further progress upwards. The most com- 

 mon of these are two aquatic bugs of different gene- 

 ra the one (Gerris locustris, LATR.) with a long 

 blackish body and legs, and white belly, though more 

 clumsy in form than the water measurer (Hydrometra 

 stagnorum) formerly mentioned; and the other (Ve- 

 lia currens, LATR.), with short body and feet, 

 black, with a red line running along each side. We 

 have been still more amused with a dark greenish 

 gray spider (Lycosa Saccata, LATR.), which, when 

 we approach near its haunts on the margin of a 

 stream, does not take shelter in the grass, nor in the 

 holes of the bank, as most of its kindred would do, 

 but trips away over the water, where it appears to 

 know instinctively that we cannot so easily pursue it. 

 This is not, however, the diving water spider (Jlr- 

 gyroneta aquatica), for though it can dive and remain 

 under water, it does not seem to relish this, except 

 when driven to the measure.* 



6, Hydrometra stag-riorum, c d, Hydrachna Geographica, Latr., 

 front and back view, both magnified, e, Velia rivulorum, Latr. 



* J. R. 



