622 THE CEINOIDEA CABIERATA OF NORTH AMERICA. 



cal, paved by small, irregular pieces, interspersed with nodose larger ones. 

 Orals proportionally small, as also the radial dome plates. Anal tube 

 comparatively small, and apparently short. Column composed of joints 

 alternating in size ; the internodal joints knife-like, the nodal ones rounded 

 at their margins, and slightly crenulated. A similar crenulation occurs also 

 at the rim of the basals, giving it the appearance of a stem joint. 



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

 Iowa. 



Types in the collection of Wachsmnth and Springer. 



Remarks. — This species resembles Actinocrinus tenidsculptus in the style 

 of ornamentation ; but differs from it decidedly in the arm structure, and 

 the form of the ventral disk, which is very much lower, and the anal tube 

 much smaller. 



Correction. — The specimen represented by figure 3 on Plate 17, Vol. 

 VIII. of the Illinois Geological Report, which was referred to this species, 

 represents a good example of Ccwtoerinus Arnoldi. 



Cactocrinus nodobrachiatus W. and Sp. 

 Plate L VII. Figs. 1 and 2. 



1887. Actinocrinus nodobrachiatus — ^. and Sp.; Geol. Rep. Illinois (1890), Vol. Till., p. 165, Plate 15, 



Fig. 5, Plate 16, Fig. 10. 

 1S90. Actinocrinus nodobrachiatus — S. A. JIillek ; N. Anier. Geol. and Palseont., p. 219. 



Specimens buff colored with brownish tint. Dorsal cup inverted bell- 

 shaped, the sides moderately convex, abruptly spreading below the arm 

 bases. Plates decidedly convex, deeply pitted at their angles, and covered 

 with radiating ridges, which, though moderately well defined near the edges 

 of the plates, are in the central portions either obsolete or become indistinct, 

 even in well preserved specimens, and appear as if they had been worn off 

 by attrition. 



Basals short, expanding into a conspicuous rim with a sharp edge, which 

 projects beyond the limits of the column; interbasal sutures deeply notched, 

 giving to the base a tripartite outline. Eadials and costals decreasing in 

 size upwards, the former as long as wide, the latter wider than long. First 

 costals hexangular, sometimes pentangular, or even quadrangular when not 

 in contact at any side with the interbrachials of the second range; the 

 second costals almost twice as wide as high. Distichals one, smaller than 

 the costal axillaries. Palmars one, small, the two inner ones axillary and 



