The Echinoid Directory

Family Arachnoididae Duncan, 1889, p. 158

[=Fossulasteridae Philip & Foster, 1971, p. 576]

Diagnosis	Clypeasterina with: apical disc with four gonopores; peristome flush on oral surface; combed areas present (alternating rows of aligned accessory pores and tubercle rows) except in highly paedomorphic forms.
Range	Oligocene to Recent; worldwide.

Diagnosis

Clypeasterina with:

apical disc with four gonopores;
peristome flush on oral surface;
combed areas present (alternating rows of aligned accessory pores and tubercle rows) except in highly paedomorphic forms.

Range

Oligocene to Recent; worldwide.