to the lateral and ventral sides of the claw, but does not extend to the dorsal 

 side; on the dorsal surface of the distal part of the claw of some forms 

 there are one or two small claws (sometimes there are more than two); 

 the ventral surface sometimes bears one or several spinules; the fully 

 sclerotized, blunt or pointed part of the claw begins at this part. The claw 

 bears 8 setae. The following arrangement of setae is present in most 

 families (Figures 14 and 15): seta 1 is situated subdor sally, slightly medial* 

 in the basal part; seta 2 is situated opposite the groove or slightly more 

 basally; seta 3 is situated in the distal part, subdorsally; seta 6 is situated 

 28 on the outside; setae 7 and 8 are situated ventrally, in the basal part; seta 5 

 is situated near seta 8 or subventrally (on the outer side); seta 4 is situated 

 more medially. 



FIGURES 13-15. Anal legs: 



13 — anal legs of Worm aid ia occipitalis, lateral, parts "a", 

 "b" and "c" and claw (after Nielsen); 14 — Rhya cophila obli- 

 terata, outer side of claw (after Kachalova); 15 — Hydro - 

 psyche angustipennis, claw, outer side (A) and inner side (B). 



The anal legs of the larvae are an important organ which bears a great 

 mechanical load; they are very variable, adapted to different methods and 



* The side of the anal legs directed toward the median axis of the larva. 



24 



