Genus

Chrysso: O. Pickard-Cambridge, 1882: 429.

Arctachaea: Levi, 1957: 102 (synonym by Levi and Levi 1962: 16).

Argyria: Yaginuma, 1957: 11 (synonym by Levi and Levi 1962: 16).

Argyroaster: Yaginuma, 1958: 37 (synonym by Levi and Levi 1962: 16).

Type species.

Chrysso albomaculata O. Pickard-Cambridge, 1882 from the Americas.

Remarks.

The morphology of the copulatory organs in “ Chrysso ” species is highly variable. Therefore, we choose the type species, Chr. albomaculata, along with eight morphologically similar species from North and South America as the true Chrysso: Chr. albomaculata O. Pickard-Cambridge, 1882, Chr. diplosticha Chamberlin & Ivie, 1936, Chr. huanuco Levi, 1957, Chr. indicifera Chamberlin & Ivie, 1936, Chr. mariae Levi, 1957, Chr. sulcata (Keyserling, 1884), Chr. vallensis Levi, 1957, and Chr. vexabilis Keyserling, 1884.

Diagnosis.

We provide the diagnostic characteristics of the true Chrysso in the current paper. The true Chrysso (figs 1–7, 9, 11, 13, 15, 21–31, 34, 35 in Levi 1957; figs 7, 8, 12 in Buckup and Marques 1996) can be distinguished from other theridiid genera by the following combination of characteristics: (1) opisthosoma longer than wide or high, posterior part extending beyond spinnerets; (2) median apophysis almost as large as tegular apophysis; (3) embolus arising from prolateral part of embolic base and retrolaterally elongating, then curved in clockwise direction; (4) copulatory ducts sac-like; and (5) spermathecae spherical.