Arbacia incisa A. Agassiz 1872  (Synomym for Arbacia stellata Blainville 1825)

Family: Arbaciidae

Order: Arbacioida

Locality: Mexico, Baja California,Magdalena Bay, beach drift, 2001

Dimensions: 40 Ø x 19 mm

 

Arbacia incisa A. Agassiz 1872 is probably a junior synonym for Arbacia stellata Blainville 1825. Already Mortensen in his Monograph of the Echinoidea, II, page 577, had some difficulties, because both names were in use. He wrote: In any case I think it objectionable, simply to use the name incisa, without giving at the same time the name stellata as a synonym, so that any body, also when not familiar with the object, may be able to see which species is meant with the name.

Arbacia incisa or stellata is easy to distinguish from other Arbacia species by its alternating coloured (red to purplish) spots in the naked aboral interambulacral area.