39, see text Masteria is a genus of curtain web spiders that was first described by L. Koch in 1873.

[4] They occur in the tropics of Central to South America, Asia and Micronesia, with one species found in Australia.

M. petrunkevitchi males are 4 millimetres (0.16 in) long and females are 5 millimetres (0.20 in) long.

M. lewisi, M. barona, and M. downeyi are slightly smaller and have only six eyes.

[5][6] Most species in the genus have six eyes, but two (Masteria caecia and Masteria pecki) have no eyes.