542 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
Megistocrinus multidecoratus (Barris). 
Plate XLIX. Fig. 6. 
1885. Megistocrinus nodosus, var. multidecoratus — Barris; Proceed. Davenp. Acad. Nat. Sci., Vol. IV. 
p- 100, Plate IL., Figs. 3 and 4. 
1885. W. and Sp.; Revision Paleocr., Part III., p. 113. 
This species agrees in the general form and the arrangement of the 
plates closely with JZ. nodosus, but differs essentially in the extent and char- 
acter of its ornamentation. The plates, instead of having a single central 
node, are covered by series of nodes, and these are not restricted to a few 
plates as in that species, but cover every plate of the calyx. The nodes are 
as arule well defined, but of irregular size and without definite arrangement, 
and they vary in number in different plates; the radials, costals, and first 
interbrachials have from five to twelve, which are arranged in rows; while 
the higher brachials seldom have more than two or three at the most. The 
plates of the tegmen are also highly ornamented, each one bearing a central 
node, from which rows of smaller nodes radiate to the angles. It may be 
further stated that in this species the dorsal cup is less flattened at the bot- 
tom, the radials are proportionally larger, and the first costals take part in 
the lateral walls, and not in the truncated lower portions. Number of arms, 
position of anus, and form and arrangement of orals and radial dome plates 
as in the preceding species. 
Florizon and Locality. — Hamilton group; Alpena, Mich. 
LTypes in the Davenport Academy of Natural Sciences. 
ftemarks. — We regard this form as a good species, and not a variety of 
M. nodosus as supposed by Barris; the differences are very marked and con- 
stant. We examined a large number of specimens of both forms, and 
experienced no difficulty in distinguishing them promptly. 
Megistocrinus rugosus Lyon and Cass. 
Plate XLVIIT. Figs. 6a, b, ¢. 
1859. Lyon and Cass. ; Amer. Journ. Sci., Vol. XXVIII, p. 243. 
1881. W. and Sp.; Revision Paleocr., Part IL., p. 138. 
Calyx depressed, its height to the base of the anal tube one third less 
than its width. Dorsal cup shallow basin-shaped, yet considerably higher 
than the tegmen, three times as wide as high, truncated to the middle of 
