EXTERNAL ANATOMY OF INSECTS. 697 



in the same species at different periods of its growth, are 

 usually ovato-lanceolate, or obtusangular, furnished on 

 their exterior edge with what appears to be a longitudi- 

 nal sucker, and supported between their bases, or at the 

 base, both within and without, by triangular, conical, or 

 subglobose props. With regard to the use of these organs, 

 it has not been clearly ascertained. Amouroux states 

 that he has seen the animals use them as feet, and he con- 

 jectures that by them they may fix themselves and turn 

 upon them as on a pivot, when they have to make a re- 

 trograde movement 3 . M. Latreille, from their having 

 branchial pouches immediately under them, seems to* 

 think that they are connected with respiration 5 . This 

 may be true; but from the suckers just described, I am 

 inclined to think with Amouroux, that they are useful to 

 the animal in its motions, and that like the suckers of the 

 Gecko, flies, &c, they enable it to support itself against 

 gravity and to climb perpendicular surfaces. 



Whether the five obtriangular plates, elevated on a 

 pedicle, which are found arranged in a series on the un- 

 der side of each of the jointed coxes of the posterior legs 

 in Galeodes, are at all analogous to the pectens of scor- 

 pions, has not been ascertained . M. Leon Dufour 

 watched them very attentively in one species ( G. intrepid 

 dzes), but he could observe no motion in them d . 



a Amouroux Insevtes Venimeux, 44. 

 b Observations Nouvelles, &c. Mem. du Mus. viii. 177- 

 c iV. Diet. d'Hist. Nat. xii. 370. 



d Descr. de six Arachnides, &c. Ann ales Gen. des Scienc. Phys, 

 1820. 19. t.lxix.f. 7.d. 



