The Echinoid Directory

Pseudechinus Mortensen, 1903, p. 106

[=Gymnechinus Mortensen, 1903, p. 115, type species Echinus robillardi de Loriol, 1883; =Notechinus Doderlein, 1905, p. 623, type species Echinus magellanicus Philippi, 1857 ]

Diagnostic Features	Test low domal in profile with rounded ambitus and somewhat flattened oral surface. Apical disc hemicyclic (ocular I insert), with relatively small periproct (dicyclic in some species). Gonopores close to margin. Single large tubercle on each genital plate. Periproct eccentric, with suranal plate usually distinct. Periproctal opening strongly displaced from centre; large suranal plate differentiated. Ambulacral plating trigeminate, in echinid style. Pore-pairs in weakly to obviously offset triads; no phyllodes adorally. Primary tubercle on each ambulacral plate plus slightly smaller secondary tubercle on ambital plates. Interambulacral plates with primary tubercle and flanking secondary tubercle on interradial side of ambital plates; smaller secondary tubercles on adradial side in two rows. Tubercles small and non-crenulate or more or less non-crenulate. No sutural pores or pits; no scultping. Peristome weakly sunken with almost no buccal notches. Peristomial membrane naked except for 10 buccal plates Perignathic girdle relatively stout with apophyses and auricles that are fused perradially. Spines short and simple.
Distribution	Miocene to Recent; Australia, New Zealand, South America and Antarctica
Name gender	masculine
Type	Echinus albocinctus Hutton, 1872, p. 12, by original designation.
Species Included	P. albocinctus (Hutton, 1872); Pliocene - Recent, New Zealand. P. flemmingi Fell, 196; Recent, New Zealand. P. grossularia* (Studer, 1880); Recent, New Zealand. P. hesperus Clark, 1938; Recent, Australia. P. huttoni Benham, 1908; Recent, New Zealand. P. magellanicus (Philippi, 1857); Recent, southern South America and subantarctic. P. marionis (Mortensen, 1936); Recent, Marion Island. P. notius (Clark, 1916); Recent, Australia. P. novaezealandiae (Mortensen, 1921); Recent, New Zealand. P. variagatus Mortensen, 1921; Recent, New Zealand. P. murrayensis (Philip, 1969); Miocene, Australia. P. robillardi (de Loriol, 1883); Recent, Indian Ocean, Littoral to 70m. P. pulchellus (Mortensen, 1904); Recent, West Pacific; 5-50 m. P. epistichus (Clark, 1912); Recent, Philippines, Littoral to 35 m. P. abnormalis (Clark, 1925); Recent, Indian Ocean, 54 m.
Classification and/or Status	Euechinoidea; Camarodonta; Temnopleuroida. Monophyletic.
Remarks	Mortensen, T. 1903. The Danish Ingolf-Expedition 1895-1896. Vol. 4, No. 2. Echinoidea, pt. 1. Copenhagen, 198 pp. Mortensen, T. 1943. A monograph of the Echinoidea Part III.2, Camarodonta 1. C. A. Reitzel, Copenhagen. Philip, G. M. 1969. The Tertiary echinoids of South-Eastern Australia IV. Camarodonta (2). Royal Society of Victoria Proceedings 82, 233-275, pls 3-16.