1971 ] 
Levi — Orb-W eaver Genera 
241 
may extend to a point on thorax, or only surround eyes ( H . groen- 
landica , Fig. 93). Sternum orange to dark brown. Legs orange, 
rarely with longitudinal lines in H. singaeformis , and very rarely 
banded in some individuals of H. rubens. Juveniles may have white 
pigment spots on dorsum of carapace and sometimes on sternum. 
Abdomen with little hair and with two longitudinal black bands 
indistinctly separated by a lighter area, but fused posteriorly (Figs. 
66, 83). Bands very distinctly set off toward lighter sides (Figs. 53, 
65, 82). The dark bands are usually darkest anteriorly and pos- 
teriorly. There may only be four black spots on dorsum, or they may 
be completely missing; sometimes abdomen entirely black. The sides 
may have an additional black band (Fig. 53). Venter of abdomen 
black with a white longitudinal line on each side (Figs. 53, 94). 
Males have abdominal pattern less distinct. Smaller individuals of 
H. rubens and females of H. alberta may have the dorsal muscle 
spots sclerotized. Total length of females is 2.4-5. 1 mm, of males 
2.2-3. 5 mm. 
Natural History. Hypsosinga make a complete orb probably 
with a retreat. All species are most commonly collected by sweep- 
ing vegetation. Males are mature in spring, the females throughout 
the season. 
Distribution. Species of Hypsosinga are only known from Eurasia, 
North Africa and North America. 
Keys to American species of Hypsosinga 
1 a. Female epigynum with a median depression (Fig. 102). Male 
unknown; Western Canada alberta 
ib. Female epigynum with a median, raised septum (Figs. 49, 61, 
90 ) 2 
2a. Epigynum with septum having sides almost parallel and septum 
about one-third width of epigynum (Fig. 49) ; male embolus 
long and thread-shaped (Figs. 55-57) variabilis 
2b. Sides of epigynal septum not parallel, or if parallel not as wide 
as one-third of epigynum; male embolus short 3 
3a. Sides of septum almost straight, septum triangular in appear- 
ance (Figs. 76, 77); embolus of palpus long and thin, much 
narrower than the space surrounded by it and terminal apophysis 
( Figs. 87, 88) rubens 
3b. Side of septum concave (Figs. 61, 90) ; embolus of palpus as 
wide or wider than long, wider than space surrounded by it 
and terminal apophysis (Figs. 70, 98) 4 
