( cviii ) 



are somotimes furnished witli flesliy pads, as in the Locristidae ; 

 with a membranous terminal lobe as in the Buprestidx and 

 other Coleoptera. Sometimes there is a line of stiff hairs or 

 bristles on each siile, or the surface is beset with bristles all 

 over, or is hairy or velvety. At the apex of the terminal 

 joint there are two claws varying greatly in shape and struc- 

 ture. Occasionally these are absent. Between the claws 

 there is a more or less fleshy lobe or pad which assumes 

 various shapes, and is sometimes divided into two, and has 

 received various names. For my present purpose I will refer 

 to it as the j^ulvillus. 



Primarily the claws are only bristles, biit they have been 

 modified to perform certain functions. They are often im- 

 movable, so that they are described as connate, divergent, or 

 (when they are at right angles to the axis of the tarsus) divari- 

 cate. Perhaps quite as often they are to a certain extent 

 movable, but they are not controlled directly by muscles, but 

 by another method. A noteworthy example is the large claw 

 of some of the Rutelid Coleoptera, which is capable of being 

 bent back on the tarsal joint, as the blade of a penknife is 

 closed in its handle, so as to make a perfect grasping instru- 

 ment. In the Melolonthid genus Aiicistrosoina, both claws 

 turn back equally. In the curious Neuropterous genus Biftacus, 

 which has but a single large claw, this acts in the same way. 



The claws in a large number of insects are quite simple, 

 more or less curved, of various thicknesses at the base, gener- 

 ally pointed at the apex. Sometimes on the underside of the 

 claw there is a tooth which may be in any position ; occasion- 

 ally there are two teeth, but this is not common. Wlien later 

 on I refer to toothed claws, I mean those with a single tooth. 

 In some instances there is beneath the basal part of the claw 

 a vertical, compressed, blade-like plate or enlargement. Some- 

 times this is confined to the base, at others it extends nearly 

 to the apex, leaving only a narrow incision between it and the 

 tip of the claw. This is referred to as an appendiculate claw. 

 Another form of claw is what is described as bifid, that is, as 

 if a cut had been made at the tip with a sharp knife, thus 

 making two points. The two points may be one below the 

 other, but very often the incision is slightly lateral, so that 



