Paraphelliactis pabista Dunn 1982

Paraphelliactis pabista Dunn, 1982

(Figures 28–29, Appendix 12)

No synonyms

Diagnosis. Column light tan to brown, 10 to 80 mm long; pointed tubercles arrayed in longitudinal rows along endocoels. Pedal disc often attached to cylindrical object such as worm tube (Figure 28) or holds small stone or bolus of mud. Aborally thickened tentacles more numerous than mesenteries at mid-column (to more than 150 tentacles vs. 96 mesenteries). For a detailed description of P. pabista, see Dunn (1982); Sanamyan and Sanamyan (2007) added information.

Cnidae. Spirocysts, basitrichs, microbasic p -mastigophores.

Distribution. Paraphelliactis pabista was described from off the coast of British Columbia (Dunn 1982). Sanamyan and Sanamyan (2007) reported the species in the Gulf of California, Mexico. We examined additional specimens from California to British Columbia and extend the depth range of the species to 1,426 to 4,100 m (Figure 29).

Taxonomic remarks. The other species of Paraphelliactis, P. spinosa Carlgren, 1928b (the type species) and P. michaelsarsi Carlgren, 1934a, were moved to Phelliactis Simon, 1892, by Riemann-Zürneck (1973). However, Riemann-Zürneck (1973) did not report the ratio of mesenteries to tentacles in specimens of the two species, key to distinguishing the genera. Thus, as Sanamyan and Sanamyan (2007) contended, the type species of Paraphelliactis (P. spinosa) should be regarded as valid and Paraphelliactis pabista should remain the valid name of the species we examined from the northeastern Pacific.

Material examined. See Appendix 12.