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In the July number of the American Journal of Science for this year 

 (1876), vol. xii, page 81, Mr. G. B. Grinnell, of New Haven, has de- 

 scribed a very interesting new genus and species of Crinoidea, from the 

 Cretaceous rocks of the West. This fossil was first discovered by Pro- 

 fessor Marsh, some years back, in Utah, and has since been found in 

 Kansas. Professor Mudge had also sent specimens of it to me last win- 

 ter from Kansas, and I had in course of preparation the accompanying 

 cuts, with the view of illustrating and describing it; but on learning 

 from Professor Marsh that Mr. Grinnell was about to describe it, my 

 name and description were withheld from publication. 



Mr. Grinnell kindly sent me, soon after, a copy of his description and 

 figures in advance of the issue of the Journal of Science in which they 

 are published ; and on examining these, I find that our specimens show 

 some parts of its structure more clearly than those studied by him. 

 Consequently, it seems desirable that our cuts, with some additional 

 remarks on this curious Crinoid (the only known American Cretaceous 

 type of the order), should be published. 



Like those investigated by Mr. Grinnell, noue of our specimens are in 

 a condition to show the base of the body 5 but from its general physi- 

 ognomy as presented in our specimens, and more especially from the 

 entire absence among the numerous associated fragments, of any disks 

 of columns, I think Mr. Grinnell very probably right in supposing that 

 it may have had no column, or, in other words, may have been free. 



As nearly as can be determined from the specimens yet known, the body 

 of the type-species seems to have presented a slightlydepressed-subglobose 

 form, and is composed of nearly flat, or scarcely convex, thin plates, joined 

 together by slightly-channeled sutures, and without costse, nodes, or 

 other distinct markings. In some instances, these body-plates present 

 the appearance of being a little beveled along their edges, and irregu- 

 larly subimbricating ; but this appearance maybe deceptive. As already 

 stated, we know nothing of its base, or of its subradial pieces,' if it pos- 

 sessed the latter. If it was a free Crinoid, and at all related to Marsu- 

 pites, it will probably be found, like that genus, to have a central piece, 

 surrounded by basals, alternating with subradials, the latter also alter- 

 nating with and supporting the radial series. It may, however, be as 

 widely distinct from Marsupites in the structure of the basal parts of its 

 body as in those above. 



Our specimen, represented by theforegoingcut, Fig. B, showstwoof the 

 rays, with their divisions, one of the interradial fields with parts of two 

 others, and two of the interaxillary spaces. Each of the two rays thus seen, 

 at least as far down as they can be traced, has three primary radial pieces, 

 the lowest one in each ray being wider than long and more or less nearly 

 hexagonal in outline ; while the second is narrower and hexagonal or jsent- 

 agonal, the third again larger and hexagonal, and bears on each of its 

 superior sloping sides, in direct succession, two large secondary radials. 

 On the second of the latter, a kind of false bifurcation takes place : that 

 is, there is given off here on the interradial side, a large arm-like series of 

 XJieces, the second of which is largest, while the others above diminish 

 rapidly in size upward. This arm-like series, however, does not form a 

 j)roper arm, or become free at all, excepting perhaps at its attenuated 

 upper extremity, but connects laterally over the interradial field with 

 the corresponding series from the next ray, so as completely to isolate 

 the interradial pieces, and to unite with each other and with the divis- 

 ions of the rays on each side, to form a part of the walls of the body. 



Going back to the second of the secondary radials from which each 

 of the lower arm-like series mentioned above is given off, we find that 

 the main division of each ray is continued almost directly onward from 



