Mode of life and habitats. An element of the "fauna hygro- 

 petrica, " usually in forests near springs, among humid moss, in shallow 

 water between fallen leaves, or in humid detritus; Even careful search did 

 not reveal a specimen in springs in the water; found occasionally in small 

 overflows of springs, between roots or decaying leaves in forest brooks. 



Distribution. Western part of the European USSR. In addition, 

 i^^urope. 



368 4. Genus Lasiocephala Costa 



Full-grown larva. Length 7.1—8.0 mm. Head dark, with numerous, dark, 

 oblong dots. Pronotum uniformly dark, with light oblong dots; mesonotum 

 dark anteriorly, lighter posteriorly; tergites of metanotum indistinct, 

 marked by setae. 



Gills single, on segments 2—6, presegmental and postsegmental on 

 segments 3—6. 



Case conical, curved, naade of sand grains. 



Mode of life and habitats. Brooks with cool water and 

 moderately rapid current. 



Distribution. Western part of the European USSR. In addition, 

 Europe. 



1. Lasiocephala basalis Kolenati 



Pictet, 1834:Plate XIV, Figure 3.- Hagen, 1864:238.- Mayer, 1867:168. 

 Klapalek, 1888:31-34, Figure 11.- Ulmer, 1903:91.- Thienemann, 1905b: 

 528-529, Figures 51, 121.- Ulmer, 1909:275, 317, Figure 462.- Lestage, 

 1921:890-896, Figures 316-318.- Brindle, 1964:198, Figure 12. 



Number and arrangement of gills of L. basalis 



Full-grown larva. Length 7—9 mm; greater part of body uniformly wide. 

 Head reddish brown, with numerous, light, oblong dots. Mandibles short, 

 massive, blackish brown; teeth blunt, short, dorsal and ventral blades with 



one tooth in addition to distal tooth; 

 brush in form of a narrow tuft of hairs 

 near dorsal margin (Figure 623). 



Pronotum reddish brown; setae, as 

 in Lepidostoma, moderately long, 

 black, situated at anterior margin and 

 in a transverse row in middle of 

 sclerite. Mesonotum as in Lepi- 

 dostoma, formed by a square plate 

 in each half, brown anteriorly, lighter 

 posteriorly; setae at anterior and 

 posterior margin, dark, strong, few. 



Forelegs massive, as in preceding 

 forms, much shorter than other legs. 



Abdominal segment 1 without dorsal 

 process; lateral processes blunt, low. 

 Gills single, on segments 2—6. 



Segment 



Dorsal 



Ventral 



2 





1 



3 





1 

 1 



4 





1 

 1 



5 





1 

 1 



6 





1 

 1 



460 



