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DescriptionAcanthocorys umbellifera: Under this name I have entered a form which has the appearance of a species of the division Dicyrtida, but is certainly not fully developed. It is remarkable, as also Haeckels illustration, for a rather large cephalis and a short, broad thorax. The spines in the thorax, protruding from the free brim like long, fine spikes are characteristic. Some of these spines are weaker than the others and are branches of them. The cephalis is well supplied with long, needleshaped byspines. There is also a similar apical spine, which here, as in Lithomelissa, is the spine D and runs in the wall of the cephalis, thus not forming any inner columella. My species differs from Haeckels only in the want of byspines on the thorax. This species occurred very rarely and sparsely in the material from the northern coasts of Norway: 19/1 1899, 40 miles NW of Gaukværø, 0-700 m; 29/1 1899, Malangen, 0-300 m. Distribution: More frequent on the west coast of Norway, numerous in the Oster Fiord, near Bergen, at a great depth (up to 600 m), 13/6 1900. Cleve mentions the species from a few places in the Atlantic, west of Ireland and more to the south, as well as from several places far north, to the north west point of Spitzbergen. In these northern places, the species was only found in deep water. Haeckel mentions it from the Azores and the Mediterranean. Hence Cleve considers the species to belong to Styliplankton. It seems, however, judging from the places mentioned where it has been found, to have about the same distribution as Plectacantha, and is probably boreal oceanic. It is, however, quite possible that Haeckels is a distinct species.