RHODOCRINID^. . 229 



plates of the other areas. Anal opening excentric, directed upwards, placed 

 within a large protuberance, composed of rather large plates. Ventral disk 

 convex, depressed at the interradial spaces, and constructed of small, irre- 

 gular, convex pieces without definite arrangement. 



Horizon and Locality. — Kinderhook group ; Le Grand, Marshal Co., and 

 Burlington, Iowa. 



Tyjpes in the Museum of Comparative Zoology at Cambridge, and in the 

 collection of Wachsmuth and Springer. 



Remarks. — This species is nearest allied to R. Kirlyi, from which it is 

 distinguished bv its more globose form, more slender arms, by the ridge- 

 like series of anal plates, and the absence of interaxillaries. In the Le Grand 

 beds this species is readily identified by its color, which is invariably hght ; 

 while all specimens of i?. Kirlyi are dark colored, and those of B, watersianus 

 intermediate between the two. 



Rhodocrinus parvus S. A. Millek. 



1891. S. A. Miller; Geol. Eep. Missouri, Bull. 4, p. 39, Plate 5, Kgs. 8, 9. 



Closely allied to R. nanus, but a somewhat smaller species and the calyx 

 more depressed. Calyx subglobose, wider than high ; the plates moderately 

 convex, and covered in exceptionally well marked specimens by obscure 

 ridges* passing from plate to plate; suture lines distinct. Infrabasals slightly 

 extending beyond the cohimn. Basals the largest plates of the calyx, bend- 

 ing gradually upward. Eadials nearly as large as the basals. The two 

 costals together smaller than the radials, and frequently anchylosed. Dis- 

 tichals fL\Q, very small, only the first a calyx plate, the succeeding ones free ; 

 the upper axillary, and supporting two arms, which do not branch again. 

 Arm openings arranged in pairs, each pair separated by a wide interspace. 

 Arms delicate, composed of two series of deeply interlocking, cuneate pieces, 

 the intervening sutures grooved. Pinnules not in contact laterally. The 

 plates interposed between the radials very large, especially that of the anal 

 side Interbrachials 2, 3, and 2, apparently also at the anal side. The 

 ventral disk not exposed in the specimens. 



Horizon and Locality. — Lower part of Warsaw limestone; Booneville, Mo. 



Types in the collection of Mr. S. A. Miller. 



* We are led to believe that the ridges in Miller's figures are too distinct and misleading. In five speci- 

 mens in the Missouri State collection with Miller's label attached, there are no ridges at all, and the surface 

 is smooth or slightly roughened. That this is not owing to the preservation is shown by the fact that the 

 other parts are sharply defined. 



