both lateral surface setae short and strong, brownish black; one situated 

 near the black margin and the second slightly anteriorly. The distal seta 

 of the trochantin of the prothorax resembles the lateral setae of the dorsal 

 sclerite. 



The anterior part of the pleural region of meso- and metathorax has 

 one sausage-shaped upward-curved tracheal gill which is deeply constricted 

 at the base in the angle formed by the dark sclerites of the pleuron; setae 

 as in Rhyacophila s. str. 



Forelegs brown, mid- and hind legs light brown; claws and tarsi of all 

 legs darker than the other segments; chaetotaxy as in Rhyacophila 

 s. str.; the large setae are thicker. 



FIGURE 227. Rhyaco- 

 phila forcipulata 

 Mart. Head, thorax and 

 abdominal segments 1 

 and 2, dorsal 



FIGURES 228 and 229. Rhyacophila forcipu 

 lata Mart.: 



228 - gill of abdominal segment 6; 229 — right 

 anal leg, outer view. 



Abdominal gills present on segments 1—8; each gill (Figure 228) consists 

 of a short stalk with a small process (homologous to the dorsal branch of 

 complex gills) with two distodorsal filaments; the other two filaments are 

 situated more ventrally; all 4 filaments are arranged in a row; they are 

 curved and directed upward, in one plane; the ventral branch is light and 

 thinner; however, it forms one row with the other filaments, and is not 

 opposed to the other 3 like the thumb of the hand, as was assumed by 



245 



