The Echinoid Directory

Aceste Thomson, 1877, p. 376

[ =Acestina Lambert & Thiery, 1925, p.432 (nomen vanum)]

Diagnostic Features	Test cordate with deep anterior sulcus; wedge-shaped in profile with tallest point to rear. Apical disc ethmolytic, with 2 gonopores (anterior pores missing); plating more or less fused. Anterior ambulacrum deeply sunken aborally; pore-pairs enlarged and uniserial - associated with large funnel building tube-feet with large rosetted discs. Paired ambulacra flush and non-petaloid; rudimentary pore-pairs only adapically. Periproct inframarginal on undercut posterior face. Peristome at anterior margin and forward-facing so entirely covered by the labrum in oral view. Labral plate elongate and narrow but not extending beyond the first ambulacral plate; in broad contact with sternal plates. Sternal plates broad and triangular; densely tuberculate; rear coincides with ambulacral plate 5. Post-sternal plates biserially offset. Aboral tuberculation fine, uniform and dense. Oral tubercles also dense and uniform. Well-developed peripetalous fasciole. No other fascioles known.
Distribution	Recent; Indo-Pacific and Atlantic; c. 500-3500 m.
Name gender	feminine
Type	Aceste bellidifera Thomson 1877, p. 376, by original designation.
Species Included	A. bellidifera Thomson, 1877; Recent, South Atlantic A. ovata Agassiz & Clark, 1907; Recent, Indo-Pacific A. weberi Koehler1914; Recent, Timor
Classification and/or Status	Spatangoida, Paleopneustina, Schizasteridae. Presumed monophyletic.
Remarks	Unmistakable by its shape, deeply sunken frontal ambulacrum and apetaloid paired ambulacra. Closest to Brisaster in form, differing from that taxon in having just two gonopores, not three, and in lacking petals. Also superficially like Proraster but that taxon has an ethmophract apical disc and well developed petals. Mortensen, T. 1950. A monograph of the Echinoidea. V. Spatangoida 1. C. A. Reitzel, Copenhagen. Wyville Thomson 1877. Voyage of the Challanger, Atlantic 1, p. 376.