Numbers
5 species in BugGuide's range (North America north of Mexico)
Size
Total body length 1.4 to 5.4 mm.
Identification
G. emertoni: total body length 4 - 5.4mm. Female abdomen has paired gray spots alternating with paired light areas consisting of tiny white spots (see page 63, figure 263 in Levi 1980). Same for male. Female with enlarged chelicerae; somewhat less so in males.
G. foxi: total body length 1.4 - 2.6mm. Carapace orange, coxae and legs yellow. Dorsum of abdomen orange-white, sometimes with paired silver spots posteriorly and darker patches (see page 67, figure 273 in Levi 1980). Female chelicerae not enlarged, but slightly so in males.
G. gouldi: total body length approx. 4 mm. Distinguished by details of genitalia, and presumably by range
(1).
G. heleios: total body length under 3mm. Dorsum of abdomen light gray with black and white marks (see page 199, figure 12 in Hormgia & Döbel 1990). Same in male.
G. iviei: (known only from the male) total body length 1.4mm. Dorsum of abdomen mostly gray to black, with paired lighter patches lacking white or silver pigment.
Range
G. emertoni: New Mexico & Arizona.
(2)
G. foxi: Wisconsin, southern Ontario, and Massachusetts, south to California, Panama, & Jamaica.
(3)(2)
G. gouldi: Southern Arizona (Nogales).
(1)
G. heleios: known from the type locality, an intertidal salt marsh near Tuckerton, New Jersey, as well as a second nearby location.
(4)(1)
G. iviei: known only from the type locality in Gulfport, Mississippi.
(2) 
