261 



262 



263 



light, strong, 5 hook-shaped setae on light background, thick, dark, much 

 longer than setae of anteclypeus. 



IMandibles (Figure 459) relatively short; distal part with serrated 

 median side; basal setae short, dark, strong, about same length. 



Wing sheaths reaching nniddle of segment 4. Mid- and hind legs with 

 dark natatorial setae dorsally on segments 1 — 5 and ventrally on segments 

 1 — 3 of mid-tarsi, and dorsally and ventrally on segments 1 — 4 of hind tarsi. 



Distal saddle-shaped dorsal process of abdominal segment 1 with 10 — 

 17 small, dark brown setae laterally. 



Holding apparatus on abdominal segments 3—7; plates dark brown; 

 number of spinules: III: 3-6; IV: 3-7; V: 3-7 + 6- 10; VI: 3-8; VII: 

 4 — 9. Lateral line on segments 5 — 8, with thick, dark brown setae. Gills 

 on segments 2 — 7, as in larva. Male genitalia in form of wide, rounded, 

 ventral appendages and a much shorter, bifid penis sheath. 



Anal rods (Figure 460) shorter than in other species, tapering posterior- 

 ly, slightly curved at end, with small, apical spinules. First seta small, 

 thin, situated. at basal part, 3 remaining setae dark, large, one of them 

 near middle, the other 2 situated subapically and apically. 



Pupal case (Figure 461) usually made of sand grains, sometimes also 

 with detritus particles. Anterior and posterior end covered with a convex 

 brown membrane, with sand grains in some places and holes between the 

 sand grains; posterior end with larger holes than anterior end. Case 

 attached to substrate at posterior end by a ligament which is 0.1 —0.3 mm 

 thick, originating on a sand grain and forming an adhesive disk about 1 min 

 wide on the substrate. Posterior end of case often covered with sand. 



Mode of life and habitats. Small water bodies, close to shore; 

 in ditches with running water, often in springs and overflows, amiong decay- 

 ing leaves, in very shallow water, under almost amphibian conditions. 



Distribution. Northern and western parts of the European USSR, 

 Southern Urals. In addition. Central and Southern Europe. 



3. Potamophylax latipennis Curtis 



Struck, 1903:99, Plate II, Figure 9. - Ulmer, 1903:63; 1903b: 199 - 202, 

 Plate V, Figures 31-32; 1909:267, Figure 402. - Dohler, 1914:91, Fig- 

 ure 33. - Lestage, 1921: 766-767, 772-773, Figure 271 a, i. - Hickin, 

 1954:55-58, Figures 1-6. 



Full-grown larva. Length 18 — 20 mm. Head (Figure 462, A) mainly 

 brown, but lighter than in P. stellatus. Frontoclypeus dark at anterior 

 margin and anterior angles, with a dark dot on each side of median pit; 

 posterior part broadly black, with distinct wedge-shaped pattern; stripes 

 on sides and posterior angle of frontoclypeus, together with adjacent areas 

 of lateral sclerites, forming 3 distinct light spots. A short, narrow, light 

 stripe along coronal suture; short, transverse rows of dots on area of 

 dorsal stripes; lateral part with longitudinal punctation. Ventral side of 

 head lighter than dorsal side; gular suture short, closed; a group of dots 

 near occipital foramen; middle of each half with 2 — 3 distinct, dark dots 

 fused into a row. Setae as in species described before this. Gula 

 (Figure 462, B) long, dark. 



328 



