Histampica A.M. Clark, 1970

Stöhr, Sabine, 2024, Taxonomic analysis of the genital plates and associated structures in Ophiuroidea (Echinodermata), European Journal of Taxonomy 933, pp. 1-98 : 62-63

Genus Histampica A.M. Clark, 1970

Fig. 30

Type species

Amphiactis umbonata Matsumoto, 1915 .

Examined species

Histampica duplicata (Lyman, 1875) .

Oral GP

Oval scales, widely separated under OS, not visible externally.

Adradial GP

Bar-like narrow, flat shaft, distal end with condylar process and lip-like extension adradialwards, both connecting to condyles on RS. Proximal to condylar process on abradial edge a lateral process with flat surface, at adradial edge a larger flat process articulating with abGP. Distal adradial end somewhat wrench-shaped.

Abradial GP

Thin, flat, blade-like, abradial edge convex, adradial edge straight, distal end pointed. Articular structure a weakly offset distal part of adradial edge.

Oral shields

No special structures. Madreporite domed in centre with large opening.

Radial shield

Inner side with two low distal condyles, proximal to them a patch of finer stereom, no groove or ledge.

Figures

Fig. 30. Ophiothamnidae O’Hara, Stöhr, Hugall, Thuy & Martynov, 2018, Histampica duplicata (Lyman, 1875). A–B. Micro CT, all others SEM. A. oGP (arrowheads) in situ, internal dorsal aspect. B. Genital plates in situ. C. adGP. D. abGP. E. adGP, distal end. F. Radial shield, internal aspect. G. Madreporite, internal aspect. Scale bars: A, F=0.5 mm; B–E, G =0.1 mm.