Pentagonal [adjective]

Most of the prisms are pentagonal, though some are of four or six sides.

Each ray was pentagonal in shape, and had three towers on its exterior angles.

Shell with fifty-two sutures and fifty-two sutural meshes; with four hexagonal and sixteen pentagonal plates.

The four meshes of each equatorial and each polar plate of equal size, pentagonal, about eight times as broad as the bars.

Shell with fifty-four sutures and fifty-four very small sutural meshes, with eight hexagonal and twelve pentagonal plates.

Shell with fifty-two sutures and fifty-two sutural meshes, with four hexagonal and sixteen pentagonal plates.

Shell with fifty-two sutures and fifty-two sutural pores, with four hexagonal and sixteen pentagonal plates.

Shell with fifty-four sutures and fifty-four sutural meshes, with eight hexagonal and twelve pentagonal plates.

Shell with fifty-four sutures and fifty-four circular sutural pores: with eight hexagonal and twelve pentagonal plates.

Therefore the two opposite meshes are larger and pentagonal, the other two meshes (alternating with these) are smaller and square.