MOTIONS OF INSECTS. 



293 



species of water-beetles, belonging to the genera Hydrophilus, 

 jElophorus, Hydrcena, Parnus, Limnius, &c., thus win their way 

 in the waves. — Thus also the water-scorpion (Nepa) pursues its 

 prey ; and the little water-mites (Hydrachnd) may be seen in 

 every pool thus working their little legs with great rapidity, 

 and moving about in all directions. — Some spiders also will 

 not only traverse the surface of the waters, but as you have 

 heard with respect to one, descend into their bosom. There 

 are other insects moving in this way that are not divers. Of 

 this kind are the aquatic bugs (Gerris lacustris, Hydrometra 

 stagnorum, Velia rivulorum, &c. Latr.) The first can walk, 

 run, and even leap, which it does upon its prey, as well as 

 swim upon the surface. The second, remarkable for its ex- 

 treme slenderness, and for its prominent hemispherical eyes 

 — which, though they are really in the head, appear to be in 

 the middle of the body — rambles about in chase of other in- 

 sects, in considerable numbers, in most stagnant waters. The 

 Velia is to be met with chiefly in running streams and rivers, 

 coursing very rapidly over their waves. 1 The two last species 

 neither jump nor swim. The species of one genus of this group 

 {Hcdobates Eschscholtz) course about on the surface of the sea 

 between the tropics, and are remarkable for being the only in- 

 sects that have adopted the sea for their abode 2 , at least if we 

 except the genera of beetles ^Epus, Pogonus, Bledius, Hespero- 

 philus, &c, which burrow in the sand while covered with the 

 tide, and thus are partially inhabitants of the ocean. 3 One 

 species of Halobates (H. Streatfieldana Templeton) was captured 

 nearly midway between the continent of Africa and America, 

 by Colonel Streatfield, 87th R. T. F., where numbers of them 

 attended the Medusae. 4 



I am next to say a few words upon the motions of insects 

 that burrow, either to conceal themselves or their young. 

 Though burrowing is not always a locomotion, I shall consider 

 it under this head, to preserve the unity of the subject. Many 

 enter the earth by means of fore-legs particularly formed for 

 the purpose. The flat dentated anterior shanks, with slender 



1 Curtis, Brit. Ent. t. ii. 2 Burmeister, Manual of Ent. 567. 



3 Spence in Trans. Ent. Soc. Lond. i. 180. 



4 Templeton in Trans. Ent. Soc. Lond. i. 230. 



u 3 



