372 SMITHSONIAN INSTITUTION 



with long- stems on slabs. The characters are remarkably constant throughout this material, 

 notably the shorter intervals between the bifurcations than in other species; thus in the 

 40 rays of the eight free specimens not one has over 3 IIBr, and few have more than 4 or 5 

 outer and 3 inner in the next division ; quite a number of rami have only two IIBr, and 

 occasionally there is but one. The whole tendency is to shortness of the crown, notwith- 

 standing the large number of bifurcations. The stem apparently tapers to a point without 

 any such enlargement as in E. ithacensis, and probably without branches ; it is preserved 

 almost to the end in a specimen on a large slab, from which the terminal restoration in 

 figure 12 was made. The socket on the posterior basal for the reception of the anal tube is 

 more asymmetric than the figures show. In specimens as usually found, the rays are so closely 

 appressed that the projection of the basal at the left upper corner is hidden from view, so that 

 the tube appears as if median; and in some cases probably is so. In figure 15, Plate L, the 

 asymmetry is indicated, but further preparation of this and other specimens shows it to be 

 much more pronounced, — the structure in this respect being that of the typical Taxocrinoid. 



Types. Worthen's original is in the University of Illinois ; the others figured and 

 studied herein are in the author's collection. 



Horizon and locality. Lower Carboniferous, Kinderhook group; Le Grand, Iowa. 



Eutaxocrinus montanensis n. sp. 



Plate L, fig. 20 



Among some collections in the National Museum from the Madison lime- 

 stone in Montana is a single specimen rather closely related to the last species, 

 and yet of a habitus fairly distinct from it. The horizon is nearly equivalent to 

 the Iowa Kinderhook of Le Grand, faunally and lithologically. The rock is a 

 very similar buff limestone, but thin and irregularly bedded; and it has a 

 crinoidal fauna with an extraordinarily similar facies, yet with scarcely a species 

 that can be called absolutely identical; the differences are those due to migra- 

 tional changes, modifying the types without extinction of the fauna. The 

 specimen for which I have proposed the above species is an example of this. 

 Upon the diagnostic character of having few iBr, 3 IIBr, and a turbinate con- 

 tour, it must stand close to E. fletcheri, yet it is clearly of a more elongate type, 

 with Br relatively much longer and narrower, iBr spaces larger, and much 

 larger IBB. It is also a larger species, the calyx to the top of IAx being higher 

 by half than that of the largest specimens of E. fletcheri. The specimen is only 

 partially exposed, and somewhat distorted, so that a more detailed description 

 is not practicable ; the form of post. B as seen in the figure is misleading, the 

 left upper part being pushed under the adjoining radial. The socket for the 

 anal tube was about median. 



Type. U. S. National Museum. 



Horizon and locality. Base of the Lower Carboniferous, Madison limestone ( = Kinder- 

 hook group) ; Spring Canyon, Montana. 



