460 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
specimen of Dorycrinus cornigerus, figured in the Iowa Report, is somewhat 
misleading by having the arm-bearing plates broken. The calyx therein 
appears narrower than it naturally is, and gives no idea of the deep sinuses 
between the arm bases. 
Dorycrinus quinquelobus (Hatt). 
Plate XLII, Figs. 7, 8, 9. 
1859. Actinocrinus quinquelobus — Hau.; Suppl. Geol. Rep. Iowa, p. 15, and N. Y. State Mus. Nat. Hist., 
Plate 3.4, Figs. 18, 19, and 20. 
1873. Dorycrinus quinquelobus —Merx and WortHEN; Geol. Rep. Illinois, Vol. V., p. 880. 
1881. Syn. of Doryerinus cornigerus Hat — W. and Sp.; Revision Paleocr., Part II., p.179 (Proceed. 
Acad. Nat. Sci. Phila., p. 353). 
A little larger than the preceding species and more robust; the calyx 
somewhat higher, broader at the base; the sides less spreading and con- 
vex; basals produced downward instead of outward ; costals comparatively 
larger ; the plates, as a rule, more convex, and the suture lines more dis- 
tinct. Dorsal cup pentalobate, as high as the ventral disk, constricted at 
the basi-radial sutures; the spaces between the rays abruptly, depressed, 
and forming deep and broad notches within the arm regions. Surface of 
plates smooth. | 
Basals large, broad, the margins of the plates overhanging the top | 
‘ of the column, and forming at the bottom a concavity, which is wider 
than the column. Radials once and a half as wide as long, the upper face | 
the widest. First costals unusually large, almost two thirds the size of the 
radials, quadrangular ; sides and upper faces convex. Second costals penta- 
gonal, hexagonal, or heptagonal, considerably longer than the first, the upper 
sloping faces rather deeply excavated for the reception of the distichals. 
The posterior rays, and also the anterior one, have but one distichal in 
both divisions, which is short and axillary; its upper faces, like those of 
the costal axillaries, are excavated, supporting a single palmar, which is 
remarkable for its great length, being fully twice as long as wide. The 
antero-lateral rays in which there are no palmars have two distichals, of | 
which the first is very short, the second as long as the palmars of the other 
rays. ‘The great length of. the arm-bearing plates is one of the best char- | 
: 
acters of this species; they bend abruptly outward, are rounded on the | 
back, and are separated from each other by deep notches. Arm openings 
arranged in groups of four, two, and four; directed slightly upward. 
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