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Show 378 The most important points yet to be determined are the nature of the T> ase ( whether composed of five pieces surrounding a central piece, and wnether or not it was connected with a column), the presence or absence of subradial pieces, and whether there is an anal series of pieces differing from each of interradial series. That this Grinoid belongs to a new genus, however, there can scarcely be any doubt. At least, even if agreeing with Marsupites in the nature of its base, subradial pieces, and the absence of any column, it would still differ very widely from that genus in the possession of interradial and interaxillary pieces, as well as in the several divisions of its radial series before becoming free, and the consequent greater number and different arrangement of the pieces composing its entire body. Specimens flattened sidewise, with the arms broken off above the body, like that represented by Fig. B, at a first glance strike one as being very similar to certain forms of the Palaeozoic genus Forbesiocrinus, such, for instance, as F. Wortheni from the Carboniferous rocks. There is no probability, however, of there being any near relations between these types. As this is the only Grinoid yet found in our Cretaceous rocks, and presents some rather remarkable features, palaeontologists will await with some interest the discovery of specimens in a condition to show all of its structure. Our specimens were sent by Professor Mudge of Manhattan, Kans., from the Niobrara group of the Upper Missouri Cretaceous series, in Trigo County, Kansas; and I believe the Kansas specimens figured by Mr. Grinnell came from the same place. They certainly came at least from the same horizon. The specimen first discovered by Professor Marsh in Utah, was found associated with Ostrea congesta, Conrad, a 4 species unknown from any other horizon than the Niobrara and Benton groups; thus showing, as might be expected from the invariably restricted geological range of the species of the Crinoidea, that the specimens at these two widely- separated localities occupy about the same geological horizon. \ |