Actinostolidae with well developed pedal disc. Body usually broader than long. Column thick, smooth, without tubercles. Margin tentaculate. Tentacles rather short, robust, wrinkled in the contracted state, the inner longer than the outer. Sphincter mesogloeal, rather weak, so that the column commonly does not wholly cover the tentacles. Longitudinal muscles of tentacles and radial muscles of oral disc mesogloeal. Two deep siphonoglyphs. Numerous perfect mesenteries. Mesenteries often slightly irregularly arranged, so that in the last, sterile cycle the two partners of a pair are sometimes differently developed, one mesentery being larger than the other; but not regularly as in Actinostola. Number of mesenteries about twice as many as that of the tentacles. Only the mesenteries of the last cycle fertile. These mesenteries do not reach the oral part of the column and are, like all other mesenteries, provided with filaments. Retractors diffuse, rather weak. Cnidom: spirocysts, basitrichs, microbasic p-mastigophors.
P. sarsii Carlgren 1921
P. ingolfi Carlgren 1942
P. groenlandica Carlgren 1933
P. antarctica Carlgren n. sp.
Cymbactis actinostoloides Wasilieff [sic] 1908
Cymbactis maxima Wasilieff [sic] 1907
Definitions and contained taxa are those of Oscar Carlgren as published in 1949 : Kungl Svenska Vetenskapsakadamiens Handlingar, Series 4, Volume 1, Number 1
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