ABSTRACT
Rotula orbiculus, a multi-lunate sand dollar, was observed for the first time along near-by islands of Sierra Leone, W. Africa. Rotula is not a suspension-feeder, rather it feeds upon bottom deposits as do most clypeasteroids. A biometric analysis showed that the animal’s perimeter is growing faster than the test length as a whole; posterior notches (incomplete lunules) are rarely found in juveniles. The highly “convoluted” posterior margin may serve as sites for food collecting in older individuals.
