Notes on a small collection of Calanoid Copepods from the Northeastern Pacific, including the description of a new species of Undinella (Fam. Tharybidae)

The present paper deals with a sample of Copepoda collected by the crew of the Canadian weathership "P" in the northeastern Pacific, 50°N 145°W, on 22 September 1959 at 08.55 hours, depth 1200 m to the surface, the sample is labelled "V-3". All Copepoda Calanoida, with the exception of nauplii, have been removed from the sample and have been identified, many of the copepodids only as far as the genus. Though many Copepoda have now been described from the Pacific Ocean and the number of samples studied has reached a considerable total, its copepod fauna, particularly that of the deeper strata, is still far from satisfactorily known. This pertains particularly to the northern Pacific, an area which, in comparison to the extensively studied northern Atlantic, has only been very poorly studied. During my study of the above mentioned sample I have carefully compared the species of calanoid copepods present with the existing descriptions of Pacific species and, whenever possible, with descriptions of material from the North Atlantic. All noteworthy features that have been met with have been recorded and are presented below, along with additions to the distributional pattern of each species. The sample appears to contain a new species of the genus Undinella, which is described and illustrated here. For a number of drawings (e.g., those of Undinella acuta nova species) I am indebted to Mr. H. Heijn. List of species Calanus species..... Calarnus pacificus Brodskii, 1948 Calanus plumchrus Marukawa, 192