No workable key has yet been devised for use with the four kinds of females now referred to this genus.
Zygoballus desidiosus (Peckham), 1896
Messua desidiosa Peckham, 1896
M. desidiosa F. Cambridge, 1901
Z. desidiosus Simon, 1903
M. desidiosa Banks, 1909
Z. desidiosus Petrunkevitch, 1911
Z. desidiosus Petrunkevitch, 1925
I am very doubtful of the correctness of the assignment of the species to the genus Zygoballus. The type should be carefully studied in accord with modern methods. Apparently the species has not yet appeared in my collection. The type female was sent to the Peckhams by Count Keyserling.
Zygoballus electus spec. nov.
Figures 363–367
Male holotype. Total length 2.24 mm. Carapace 1.26 mm. long, 1.02 mm. wide at level of PLE which occupy full width of carapace, .77 mm. tall and, therefore, about .75 as tall as wide; dorsal surface nearly flat back to steep posterior declivity which begins a little more than one third of the distance from PLE to posterior border and is typically abrupt for the genus; with a median longitudinal thoracic groove of moderate length beginning opposite posterior borders of PLE.
Eyes. Seen from in front, anterior row recurved so that a line tangent to dorsal borders of ALE cuts off about one twelfth of the diameter of AME. Posterior row wider than anterior row in ratio of 24 : 23, wider than middle row in ratio of 24 : 21. Quadrangle of laterals wider than long in ratio of 48 : 35. Total eye space occupies about forty fifty-sevenths of the length of the carapace. Ratio of eyes AME : ALE : PME : PLE = 15.5 : 8:5 : 1.75 : 7.5. AME contiguous to one another and to ALE. Middle eyes closer to ALE than to PLE in ratio of 11 : 9. Height of clypeus equal to about one fourth of the diameter of AME. Clypeus decorated with a rich coat of white lanceolate hair showing considerable iridescence, one long white bristle beneath outer border of AME, and probably three long, upturned, light colored bristles in lower angle between AME.
