Mode of life and habitats. Springs and brooks, in humid moss. 

 Distribution. USSR : not recorded, possibly occurring in the west and 

 southwest. In addition, Europe. 



2. Stactobia fuscicornis Schneider 



Lauterborn, 1904:129. — Thienemann, 1905b:553— 555, Figure 110.— Ulmer, 

 1906:295. - Siltala, 1907:390-393, Plate 14, Figure 3, h, i, m. - Ulmer, 

 1909:223, 292.- Vaillant, 1951b:205-208, Figures 2, 7, 11. 



Full-grown larva (Figures 492 and 493). Length 3 mm. Closely re- 

 sembling S. eatoniella, differing in that the dorsal and ventral sides of 

 the case are more sharply differentiated. Dorsal side more convex than in 

 S. eatoniella, with 3 little marked longitudinal ribs. 



Mode of life and habitats. Springs, small brooks, on humid rocks. 



Distribution. USSR: not recorded, possibly occurring in the west 

 and southwest. In addition, Europe. 



IV. Family PHILOPOTAMIDAE Stephens 



Full-grown larva. Length 7.5— 22.0 mm; body long, uniformly narrow; 

 intersegmental constrictions deep. Head narrow, dor soventr ally compressed; 

 head and prothorax narrower than the following segments of thorax and 

 abdomen, without pattern or with indistinct dots. Frontoclypeus oblong, 

 with shallow lateral indentations and broad, projecting anterior margin; 

 coronal suture short; gular suture long; gula short, broadly triangular. 

 Eyes small, divided, situated on a light area in the anterior quarter of the 

 head; antennae forming a small tubercle near base of mandibles, with 

 2 sensillae and 3 setae. Setae of head short, some of them spinelike or 

 setuliform. 



Labrum trapezoidal, narrower posteriorly, with movable lateral lobes, 

 367 membranous in its greater part, transparent whitish; a small dorsal sclerite 

 in the middle at the base; setae short; labrum retractile under the clypeus; 

 if the labrum is retracted, the lateral lobes are bent ventrally. Mandibles 

 with curved outer margin and long beak-shaped apex; upper blade reduced, 

 with 1 or 2 apical teeth; lower blade with apical and basal teeth and a small 

 serrated part between them; transverse groove and median brush absent; 

 outer setae equally long, situated at a distance from the basal margin; 

 anterior seta curved. Maxillolabium oblong; submentum trapezoidal, its 

 setae and distal setae of cardo and palpifer longer and thicker than the other 

 setae; stipes narrow, oblique, sometimes with a dark longitudinal stripe; 

 galea with 3 groups of dense hairs, which form a fan or a brush; maxillary 

 palps straight or slightly concave; the 3rd segment the longest; sclerites 

 ring-shaped; mentum very broad, longer than submentum; labium simple and 

 blunt. 



Pronotum convex, narrower posteriorly; posterior margin broadly black; 

 lateral margin also partly black; anterior angle of sclerite forming almost 

 a right angle; posterior angle not prolonged. Meso- and metathorax 



408 



