. Bulletin - United States National Museum. Science. mm. .(is = mm. Up = mm. Z-ooeciaj^^ 4Q mm Variations.—The zooecia of our specimens are a little smaller than those of specimens collected in the northern seas. The zoarium is not pigmented. These small differences would be sufficient possibly for the formation of a new variety japonica. This species is very common and has been dredged very frequently, but only Waters, 1900, and Jullien, 1903, have studied it in detail. In the Albatross material there were only seven dead specimens which have not permitted us to make a seri
. Bulletin - United States National Museum. Science. mm. .(is = mm. Up = mm. Z-ooeciaj^^ 4Q mm Variations.—The zooecia of our specimens are a little smaller than those of specimens collected in the northern seas. The zoarium is not pigmented. These small differences would be sufficient possibly for the formation of a new variety japonica. This species is very common and has been dredged very frequently, but only Waters, 1900, and Jullien, 1903, have studied it in detail. In the Albatross material there were only seven dead specimens which have not permitted us to make a serious study. Our thin sections were made from speci- mens from Greenland presented to us by Levinsen. Biology.—This is a circumpolar species. Nordgaard, 1912, has published a chart of the boreal region showing its geographic distribution. It has not been cited in the West Pacific so that our discovery com- pletes his chart. It was in reproduction (ovicelled) Au- gust 2, 1887 (1,267 meters). It can live at a temperature of 0° C. It is particu- larly abundant at depths of 20 to 160 meters; but it has, however, been dredged at 249 meters north of Norway and at 1,267 meters at Newfoundland. Occurrence.—D. 4807. Cape Tsiuka, Sea of Japan; 41° 36' 12" N.; 140° 36' E. Geographic distribution.—The reader will find the geographic dis- tribution of this species given by the authors listed above, especially on the excellent chart of Nordgaard, 1912. Plesiotypes.—Cat. No. 8036, Genus CIGCLISULA Canu and Bassler, 1927 The ovicell is hyperstomial, opening in the peristomie, never closed by the operculum with the frontal perforated by ver37 large pores. The frontal is a thick tremocyst with tubules. The apertura is oval; the peristomice bears a wide pseudorimule bordered by a peristomial avicularium. The operculum bears two large lateral bands terminated Fig. A 120.—Post end a Smitt, 1867 A. Longitudinal thin sec- tion, X16 cutting two ovicelled zooecia. The ovicell
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