Genus Ophiopus Ljungman, 1867

Fig. 32A–E

Type species

Ophiopus arcticus Ljungman, 1867 .

Examined species

Ophiopus arcticus .

Oral GP

Absent.

Adradial GP

Wrench-shaped adradio-dorsal distal end, single flat distal condyle bordered by groove, separated from round process by deep incision, process finer meshed on adradial side. Proximal half bar-like, with longitudinal groove in abradial surface. On abradial side a longitudinal groove.

Abradial GP

Absent.

Oral shields

Inner side in distal half laterally thinner with smoother, finer porous stereom. Madreporite inner side with large centrodistal opening.

Radial shield

Articular structure a low condyle and groove, large round patch of finer stereom proximal to condyle.

Remarks

Ophiopus arcticus lacks genital slits, which may explain the absence of oral GP and abradial GP.