RETEOCRINID^. 181 



RemarJcs. — The peculiarity that the smallest interradials are marginal 

 and lie next to the radials and basals, instead of diminishing in size upward, 

 as is usually the case, leads to the conclusion that these plates were intro- 

 duced between some of the older pieces, and are secondary phites which 

 cannot be homologized with the primary interradials of the Actinocrinidse. 

 The structure is well shown in oik figure, Plate IX. Fig. 1/, which represents 

 the inner floor of a fine specimen in which the arrangement of the primary 

 interradials is very little disturbed, being 1, 2, 3, all of them isolated and 

 surrounded by small supplementary pieces. We shall discuss this subject 

 further in our remarks upon Xenocrinus penicilhis and X. Baeri. 



We have had no opportunity to examine the type specimen of Glypiocrimis 

 cognatus S. A. Miller, in the collection of Dr. K. M. Byrnes of Cincinnati, but 

 from the description and the figure we are strongly inclined to regard it as 

 a large specimen of Reteocrimis Onealli, and not a variety of that species, as 

 suggested by Miller. 



Reteocrinus magnificus (Miller). 

 FMe IX., Fig. 2, 



1883. Gaurocrinus magnificus — S. A. Miller; Journ. Cincin. Soc. Nat. Hist., Yol. YI., p. 230, Plate 11, 



Eig. 2. 

 1885. Reteocrinus magnificus — "W. and Sp. ; Hevision Palseocr., Part III., p. 94. 

 1889. Gaurocrinus magnificus — S. A. Miller; North Amer. GeoL and Palseont., p. 247. 



A larger species than Reteocrinus Onealli. Calyx subovoid ; section pen- 

 tangular ; the interradial and interdistichal spaces deeply depressed ; the 

 radial ridges broad, flattened at their upper faces, and branching from the 

 middle of the radials to adjoining basals. 



Infrabasals small, almost covered by the column. Basals of medium size, 

 somewhat convex, their upper ends inflected toward the impressed inter- 

 radial areas, the interbasal suture lines deeply grooved, and forming with 

 the lower end of the radials a lozenge-shaped concavity. Kadials a little 

 narrower at the top than at the bottom. Costals two, narrow^, as long as the 

 radials, and without lateral extensions. Distichals very variable in number, 

 from two to fifteen, the three or four lower ones almost as large as the 

 costals. When there are but two distichals, which is apparently exceptional, 

 there is an additional bifurcation in the calyx ; while in the other cases there 

 is only one more bifurcation, which takes place in the free arms, and the 

 second distichals support a very large pinnule. Arms stout, rounded and 



