Psolidium Ludwig, 1886

Panina, Elena G., Stepanov, Vadim G. & Martynov, Alexander V., 2021, Psolidium kharlamenkoi-a new species of holothurian (Holothuroidea Dendrochirotida: Psolidae) from the Kuril Islands, Zootaxa 4995 (2), pp. 266-280 : 268

Genus Psolidium Ludwig, 1886

Type species. Psolidium dorsipes Ludwig, 1886 (by monotypy).

Diagnosis. Small forms (sole a few centimeters long); sole sharply set off; with feet along the edges and few to many in the mid-ventral ambulacrum; dorsal side with numerous imbricating scales. Spicules in sole, plates or buttons, smooth to knobbed; usually an external layer of small deep cups occurs. Feet with end plate and supporting plates or rods. Dorsal side usually with an external layer of cups (lacking in some species) or towers (sometimes reduced during ontogeny) and grains on the scales. Dorsal tube feet with or without an end plate and supporting rods or plates in the walls (the type species has squarish plates similar to those of Thyonepsolus ) ( Deichmann 1941; Lambert 1996).