Mode of life and habitats. Brooks and rivulets with clear water; 

 springs and overflows of springs; on bottom of stone or coarse detritus in 

 open littoral zone of lakes. 



Distribution. The European USSR, Caucasus, Siberia. In addition, 

 Europe. 



251 



Key to the Species 

 Full-grown larva 



1 (6). Head, pronotum, and mesonotum mainly dark reddish brown. 



2 (5). Dorsal side of head uniformly, or almost uniformly, reddish brown. 



3 (4). Anterior third of pronotum with numerous, small setae; dark, 



lateral naargin of mesonotum extending anteriorly, at most to 

 middle; case made of sand grains and detritus, rarely of detritus 

 only 2. P. nigricornis Pict. (p. 321 ) 



4 (3). Anterior third of pronotum with only a few surface setae; dark 



lateral margin of mesonotunn extending to most of the anterior 

 half; case made of sand grains ... 1. P. stellatus Curt. (p. 315) 



5 (2). Frontoclypeus with light spots in anterior part, on sides of 



posterior part, and at posterior angle 



3. P. latipennis Curt. (p. 328) 



6 (1). Head, pronotum, and mesonotum mainly yellowish or whitish 



yellow. 



7 (8). A short, dark stripe between eye and anterior margin of head; 



posterior part of head light around occipital foramen; case made 

 of small sand grains, or of sand grains and silt, with smooth 

 surface 4. P. rotundipennis Br. (p. 330) 



8 (7). Head light between eye and anterior margin; area around occipital 



foramen dark; dorsal side and sides with wide, dark stripes; case 

 made of coarse sand grains 5. P. excisus Mart. (p. 334) 



1. Potamophylax stellatus Curtis (Stenophylax 

 stellatus auctorum) 



Pictet, 1834:137-138, Plate VII, Figure 1. - Kolenati, 1848:67-68.- 

 Hagen, 1864: 257. - Walser, 1864: 47 - 48. - Meyer, 1867: 165. - Klapalek, 

 1893:23-25, Figure 6 .- Struck, 1900, Figure 20. - Siltala, 1902:83-87, 

 Figure 19. - Struck, 1903 : 99. - Ulmer, 1903 : 63 - 64. - Siltala, 1904c: 

 66-67; 1907: 502.- Ulmer, 1909: 267.- Lestage, 1921: 765-774, Fig- 

 ures 270, 271c,f, ],1, 275 A.- Lepneva, 1940:216, Figure 160, 17.- 

 Hickin, 1942:9-11, Figures 1 - 10. - Nielsen, 1942:534-541, Figures 133 

 135. - Philipson, 1961 : 321 - 326. - Jacquemart et Coineau, 1963:155-168 



Full-grown larva. Length 21 — 25 mm (Figure 440). Head chestnut 

 brown, with a narrow, yellowish white periocular area; punctation dark 

 brown, not always distinct. Frontoclypeus (Figure 441, A) with following 

 light areas: anterior median, posterior in region of wedge-shaped pattern 

 and at posterior angle; anterior part of frontoclypeus with 3 median pairs 

 of indistinct dots; wedge-shaped pattern wide, consisting of small, distinct 

 dots. 



315 



