388 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
tional nodes, one to each side, of which 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 subcylindrical, 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 Hretmocrinus 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 scarcely projecting over the general surface. Column unknown. 
Horizon and Locality. — Keokuk group; Keokuk and Augusta, Iowa; 
Nauvoo, Ills., and White’s Creek Springs, near Nashville, Tenn. 
Type in the (Worthen) Illinois State collection. 
Eretmocrinus remibrachiatus (Hatt). 
Plate XX XVII, Figs. 2a, 6b. 
1861. <Actinocrinus remibrachiatus— Hari; Prelim. Notice of New Species of Crinoids, p. 11. 
1872. Batocr. (Eretmocrinus) remibrachiatus— Hain; Bull. I., N. Y. State Museum Nat. Hist., Plate 4, 
Figs. 8, 9. 
1881, Evretmocrinus remibrachiatus —W. and Sv.; Revision Paleocr., 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 
——— 
oe Sere 
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