This is because in contrast to the modern differentiation of species, the genital structures were not taken into consideration at that time.

Males' genital structures had a particular shape to aid in female resistance.

The female can best be distinguished by the form of the epigyne (the external genital structure).

For most genital structures, though, the purpose can only be guessed at.

The epigyne or epigynum is the external genital structure of female spiders.

Various tribes were considered within the proposition, with most differentiation coming from genital structure.

They are distinguished from related genera based on male genital structures.

This genus resembles Epeus in body shape and eye pattern, but has a different genital structure.

The arrangements of the suckers and genital structures were typical.

An important family character is found in the shape of the male genital structure, a style that is longer than broad.