REDESCRIPTION OF SPIROCHAETOPTERUS-SOLITARIUS (RIOJA, 1917), WITH NOTES ON TUBE STRUCTURE AND COMMENTS ON THE GENERIC STATUS (POLYCHAETA, CHAETOPTERIDAE)

Spiochaetopterus solitarius (Rioja, 1917) (Polychaeta: Chaetopteridae, originally described in the genus Phyllochaetopterus) is redescribed from newly collected material from Atlantic populations at the type lo cality: Santander Bay, northern Spain, and one population in the north west Mediterranean: Port-Vendres, France. S. solitarius is compared wi th Mediterranean material of S. costarum (Claparede, 1870), with which it was originally confused. None of the examined specimens have the ' 'antennae'' believed to be characteristic of the genus Phyllochaetopte rus (and thus thought to be present in P. solitarius). The genus Phyll ochaetopterus is briefly discussed, notes on the biology and ecology o f S. solitarius are given, and features of tube structure are describe d and illustrated. Preliminary observations confirm that the species i s able to reproduce asexually as well as sexually, as also suggested b y Rioja.