Figure 3. Pyramids of indeterminate echinoid. (1) Pyramid of indeterminate echinoid (USNM 617190a); (2) pyramid of indeterminate echinoid (USNM 617190b). Tooth comes to a single nonserrate point. (3) Pyramid of indeterminate echinoid (USNM 617190c). Scale bars = 2.5mm.