The Echinoid Directory

Holopneustes L. Agassiz, 1841, p. 9

Diagnostic Features
  • Test globular in form; approximately as tall as wide.
  • Apical disc dicyclic; gonopores at edge of genital plates. Periproct subcircular; periproctal plates small and undifferentiated; no suranal plate.
  • Ambulacral zones as wide as interambulacral zones.
  • Ambulacral plating trigeminate, with echinid compounding. Pore-zones broad, with pore-pairs forming two discrete columns, with scattered irregular pore-pairs in the broad zone in between; triads compound so that there is one primary tubercle to each two or three triads. Small tubercles occur within the pore zone.
  • Ambulacral tubercles rather irregularly developed on every second or third compound plate.
  • Interambulacral plates wide with small tubercles forming vertical and horizontal series; up to six abreast at ambitus.
  • Primary tubercles imperforate and non-crenulate.
  • Plates rather sparsely tuberculate giving the entire test a rather naked appearance, but no well developed naked interradial zone adapically.
  • Median sutures rather sharply incised and occaionally with minute pits developed at triple junctions (in juvenile).
  • Peristome small with only faint buccal notches.
  • Spines short and simple.
  • Lantern camarodont.
Recent; Australia and New Zealand.
Name gender feminine
Holopneustes porosissimus L. Agassiz, in Agassiz & Desor 1846, p. 364, by monotypy.
Species Included
  • H. porosissimus L. Agassiz, in Agassiz & Desor, 1846; Recent, Australia.
  • H. inflatus Lutken, in Agassiz, 1872; Recent, Australia.
Classification and/or Status

Camarodonta; Temnopleuroida; Temnopleuridae.



Very similar to  Amblypneustes, differing from that taxon by having a primary ambulacral tubercle to only every second or third compound plate.

Agassiz, L.  1841. Observations sur les progress récens de l’histoire naturelle des echinoderms. Monographie d’Échinodermes vivans et fossiles. Seconde Monographie, première section, 20 pp. Petitpierre, Neuchâtel.

Mortensen, T. 1943. A monograph of the Echinoidea Part III.2, Camarodonta 1. C. A. Reitzel, Copenhagen.