SOME FURTHER RECORDS OF PELAGIC POLYCHAETA FROM THE NORTHEAST PACIFIC NORTH OF LATITUDE 40° N. AND EAST OF LONGITUDE 175° W., TOGETHER WITH RECORDS OF SIPHONOPHORA, MOLLUSCA, AND TUNICATA FROM THE SAME REGION

Abstract

Seventeen species of pelagic Polychaeta from the northeastern Pacific are recorded. Of these, five (Sphaerosyllis pirifera Claparède, Dorvillea kefersteini McIntosh, Spiophanes cirrata Sars, Magelona sp., and Flabelligera affinis Sars) are species which, whilst not exclusively pelagic, are known to swim at some stage, particularly as larvae. One record (Pedinosoma curtum Reibisch) is new to the Pacific Ocean, two (Pontodora pelagica Greef and Callisona nasuta Greef) are new to the northeastern Pacific region, and four (Pelagobia longicirrata Greef, Lopadorhynchus uncinatus Fauvel, Sagitella kowalewskii Wagner, and Callizona angelini (Kinberg)) are records of northerly extensions of distribution. The first observation of a larval Cossura (probably of C. longocirrata Webster and Benedict) is recorded. Poeobius meseres Heath is recorded from a number of stations and the classification of Poeobiidae is discussed.Eight species of Siphonophora are listed, all of which constitute new records for the region covered by the present collections. Six species of Mollusca, comprising five Pteropoda and one Heteropoda, are recorded, none of which have been identified previously in northeastern Pacific plankton. Three of the genera of Pteropoda (Anopsia, Thliptodon, and Cliopsis) are characteristic of warmer seas, the other two, and the heteropod, are widely distributed. Of the two species of Tunicata listed one is new to the northeastern Pacific.