66 



which are inserted on the end of the tibia (text-figs. 2, 3 

 and 4). In frequent instances the lower claw is greatly 

 reduced, or it may be wanting altogether, as is the case 

 in Anurida. There are frequently found in relation with 

 the claws several (usually three) stiff hairs or setae, which 

 are swollen at their extremities.* These structures are 



oo 



Text-Fig. 2. — I., Isotoma palustris : m, manubrium; d, dens; 

 t, mucro. II., Extremity of fore foot. III., Byes and 

 post-antennal organ (the arrow is directing forwards.) 

 IV., Mucro. v., ' Catch ' : cp, corpus or basal portion ; 

 r, ramus. 



inserted into the distal end of the tibia, and aie known as 



tenent hairs (text-fig. 4). They appear to be modified 



glandular setee, and exude from their extremities a small 



drop of a sticky semi-gelatinous fluid. These hairs are 



adhesive in their function, and they aid tlie insect in 



climbing smooth or steep surfaces. 



* These hairs are not peculiar to the Collenibola, but are found in 

 many larva? as well as in those aduit insects in which the adhesive 

 pads or pulvilli are wanting. 



