Radially symmetrical organisms typically lack a head; the points of reference used are:

Question

Quizplus · Accepted Answer

Radially symmetrical organisms do not have a clear front or back, so the terms anterior and posterior, dorsal and ventral, and proximal and distal would not be appropriate. Instead, they have a central point around which their body parts are arranged, and the terms oral (pertaining to the mouth) and aboral (pertaining to the opposite end) are used to describe locations on the organism.

Radially Symmetrical Organisms Typically Lack a Head; the Points of Reference