690 EXTERNAL ANATOMY OF INSECTS. 
there are six? ; in Nepa and the Myriapods there is only 
one. In most insects, perhaps, the claws are simple or 
undivided’; but in Galeruca, Macrodactylus subspino- 
sus °, &c., they are bifid at the apex; as is the exterior 
claw of the four posterior legs in Chasmodia and Macra- 
spis 4, and of all in Phyllopertha horticola ; in Serica brun- 
nea the claws are all cleft at the extremity, but the internal 
tooth is broad, flat, and obtuse *; in Melolontha vulgaris 
and Pelidnota punctata*‘, the claws are armed with an 
internal tooth near the base®. In the Araneide, which 
have three claws, the two external ones are furnished with 
several parallel teeth, which the animal uses to keep se- 
parate the threads of its web, and probably for other 
purposes "; and some Predaceous beetles, as Lebia, Cy- 
mindis, and Calathus, have both their claws similarly 
furnished‘, These organs vary in their relative propor- 
tions: thus, in Anoplognathus the inner claw is much 
smaller than the other*; and in Elater sulcatus, fuscipes, 
&c., it is represented by a mere bristle; in Hoplia, in 
the anterior farsus it is not half the length of the outer 
one!; in Areoda and Pelidnota this last is the smallest. 
They vary also in length—in Rynchenus, Ascalaphus, 
&c., they are very short; in the Lamellicorns, Galeodes, 
&c., very long; and in Myrmeleon longer than the claw- 
joint. With regard to their curvature they generally 
form the segment of a circle; in many Aszlide@ they are 
2 Prate XXVII. Fic. 46. b Thid. Fie. 53, 54. 
© Jbid. Fie. 49. ¢ Ibid. Fic. 38. 
e Ibid. Fie. 39. * This structure is not general in this genus, 
® Prate XXVII. Fic. 40. h Prate XXIII. Fie. 14. 
i Prats XXVII. Fic. 43. k Tbid. Fic. 47. . 
1 Ibid. Fie. 48. 
