Irpa

Danielssen & Koren, 1882

2 species

Differs from Kolga by its elongate body and the larger numbers of lateral tube feet and dorsal papillae. (Mortensen, 1927)

Dorsal papillae 3-5 pairs, anteriorly placed, not forming a velum. Tentacle discs with 5-7 marginal lobes, each divided into about 3 lobules. Deposits, spinous rods and irregularly shaped C-s. Calcareous ring strong and continuous, each piece with 4 pairs of arms. (Hansen, 1975)