M.J. ORLOVA-BIENKOWSKAJA 

Fig. 7 S. vetulus, antenna. A, general view, B, curved seta of exopod distal segment, C, inner side of basipod, distal part, D, outer side of basipod, distal 
part, E, basipod proximal part. 
MATERIAL EXAMINED. Neotype. Type material of junior synonyms: 
S. vetulus angustifrons Lilljeborg, 1900: Lectotype (designated 
here): Sweden, Uppsala, 9. 10. 1882, leg. Lilljeborg: MPA: 92 ad. 
(ZMU, 399). Paralectotypes collected with lectotype: MPA: 
13 9 Qad., 339 Qjuv., 72 Qe., SSA (ZMU, 399). Other speci- 
mens: More than 2000 specimens (? Qad.,2 9 juv., 2 Qe.,c0°o’) 
from 30 localities (Fig. 21) in Denmark, Greenland, Poland, Bul- 
garia, European Russia, Ukraine, Georgia, Morocco, deposited in 
AC, ZMC, ZICW. Some specimens are selected from the samples 
from ZIPD. 
DIAGNOSIS. Measurements. 2 9 ad.: 1.3—2.9mm.,@ Qe.: 1,2- 
1,9mm,c' oO’: 1,1—-1,3mm. 
Female. Dorso-posterior valve prominence short, with narrow base 
and large diameter (Fig. 18). Its diameter greatly exceeds its length 
(Fig. 2). Dorsal valve margin low, not protruding backward. Depres- 
sions above and below dorso-posterior prominence small and shallow. 
Ventral head margin straight or slightly concave, sometimes with 
small prominence. Deep depression on ventral head margin near 
rostrum. Ocellus elongate. 
