388 THE CRINOIDEA CAMEEATA OF NORTH AMERICA. 



tional nodes, one to each side, of wliich those upon the radials are connected 

 with the central node by a transverse ridge. 



Basal ring slightly projecting laterally, more or less notched at the 

 sutures, and moderately excavated at the bottom. Radials twice as wide as 

 long ; their transverse ridges pointing downward, sometimes reaching as low 

 as the truncated lower end of the basals. First costals one third smaller 

 than the radials; quadrangular. Second costals generally a little wider 

 than the first, and of about the same length. Distichals two, shorter than 

 the costals. Palmars short, in rows of three, except in the posterior rays, 

 in which the subdivision next to the anal interradius, and in large specimens 

 frequently also that next to the antero-lateral rays, has two palmars followed 

 by three post-palmars. Arms twenty to twenty-four ; they are at the 

 proximal end narrow and subcj'lindrical, biserial from the first free plate, 

 and composed of moderately long pieces. The arms have not been found 

 in position ; there are found, however, along with the calyces, detached 

 pieces of Eretmocrinus arms, which probably belong to this species. They 

 are more robust than those of the preceding species, not as wide, and their 

 increase in width is more gradual ; their cross-section is semi-oval, the dorsal 

 face flat and covered with four rows of nodes, of which two are close to the 

 suture line, and one to each outer border. Interbrachials three ; the first 

 large, reaching to nearly the full height of the first distichals ; the two 

 others smaller and roofed by the palmars. The anal plate is followed by 

 three large plates, and these by three smaller ones, which are arched by the 

 post-palmars. Ventral disk bulging, larger than the dorsal cup ; the plates 

 large, of almost uniform size, and tumid. Anus excentric, very small, some- 

 times scai'cely projecting over the general surface. Column xmknown. 



Horison and Localily. — Keokuk group; Keokuk and Augusta, Iowa; 

 Nauvoo, Ills., and White's Creek Springs, near Nashville, Tenn. 



Tt/pe in the (Worthen) Illinois State collection. 



Eretmocrinus remibrachiatus (H.iLL). 

 Plate XXXVII., Figs. 2a, b. 



1861. Actinocrbms remibracUatm — Hai.l; Prelim. Notice of New Species of Criuoids, p. 11. 



1372. Batocr. {Eretmocrinus) remibrachiatus— '^kiA.; Bull. I., N. T. State Museum Nat. Hist., Plate 4, 



Kgs. 8, 9. 

 ISSl- Eretmocrinus remibrachiatus — W. and Sp. ; Reyision Palffiocr., Part II., p. 173. 



Calyx biturbinate, about as wide as high. Dorsal cup obconical, truncate 

 at the base; the sides slightly concave, spreading uniformly to the top of the 



