Genus

Type species.

Megama decimaculata sp. nov. from China.

Etymology.

The generic name is a combination of the Greek word mega (large) and ma (abbreviation of median apophysis), referring to the large median apophysis of this new genus. The gender is feminine.

Diagnosis.

Members of the genus Megama gen. nov. can be distinguished from the true Chrysso (cf. Figs 1 – 3 and figs 1–7, 9, 11, 13, 15, 21–31, 34, 35 in Levi 1957; figs 7, 8, 12 in Buckup and Marques 1996) by: (1) median apophysis posteriorly elongating, with a thin and long dorsal part almost as long as ventral part (vs median apophysis triangular, without elongation); (2) tegular apophysis tiny, almost 1 / 5–1 / 3 of the median apophysis (vs almost as large as median apophysis); (3) embolus relatively shorter than bulb, with a pointed embolic projection (vs relatively longer than bulb, lacking embolic projection); (4) copulatory ducts tube-like (vs sac-like); and (5) spermathecae longer than wide or wider than long (vs spherical).

Description.

Habitus (Fig. 4): male total length 1.48–1.88, female 1.80–3.20. Habitus generally light yellow. Carapace oval. Sternum triangular. Chelicerae with two promarginal teeth, without retromarginal teeth. Leg formula 1423. Retrolateral part of patella of legs with apophysis. Opisthosoma oval, posterior part extending beyond spinnerets; dorsal part of opisthosoma with black spots. Colulus or colular setae absent.

Male palp (Figs 1, 2): tibia almost half the length of cymbium, basal retrolateral part with two trichobothria. Cymbium longer than wide, with the basal part narrowest; cymbial hood longer than 1 / 4 length of cymbium, with curved apical part; tarsal organ larger than setal sockets. Subtegulum and tegulum with prolateral part shorter than retrolateral part. Median apophysis with triangular ventral part, and long dorsal part almost as long as ventral part. Tegular apophysis tiny, almost 1 / 5–1 / 3 of the median apophysis. Conductor cow-ear-like, connecting with tegulum via membrane. Embolus with a pointed projection; embolic tip curved in anticlockwise direction.

Epigyne (Fig. 3): epigyne slightly sclerotized. Copulatory ducts tube-like, thinner than spermathecae. Spermathecae oval. Fertilization ducts curved, arising from posterior part of spermathecae.

Composition.

Megama decimaculata sp. nov. and Meg. bimaculata (Yoshida, 1998), comb. nov.

Distribution.

China, Japan.