By THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
Orals large ; the posterior one small and lunate, owing to the almost central 
position of the large anal tube. 
Horizon and Locality. — Upper Helderberg; Clark Co., Ind. 
Types in the collection of Victor W. Lyon. 
Remarks. — Differing from all other known species of this genus in the 
great size of the calyx, the form and depth of the basal pit, in having two 
secondary interbrachials, and in the number of the slits. The specimen on 
Plate XXVI., Fig. 7, exhibiting the inner floor of the disk, is very interest- 
ing as showing the communication of the slits with the inner cavity. 
Dolatocrinus major W. and Sp. (nov. spec.). 
Plate XX V. Fig. 5. 
A very large species, in general form resembling the preceding, but with 
a shallow basal depression, four arms to the ray, and without surface orna- 
mentation. Dorsal cup depressed-bowl-shaped, almost three times as wide as 
high, flattened below; the radials and part of the costals stretched out hori- 
zontally ; the basals forming a shallow concavity surrounded by a thickened 
rim; the sides gently bending upwards and becoming parallel at the top of 
the first distichals. The plates are smooth, with the exception of a small 
rounded node upon the two costals; that of the first costal occupying the 
upper end of the plate, that of the second the median part. Radials compar- 
atively small, considerably wider than long; the upper and lower lateral 
faces almost equal; the lower margin thickened and forming a rim around 
the basal concavity. First costal as large as the radials; the upper face 
decidedly convex, and the lateral ones slightly, but the lower face straight. 
Second costal larger than the first, broadly pentangular. Distichals 1 x 10; 
large; axillary; supporting two good sized fixed palmars, and these the 
free arms. Arms twenty, arranged at almost equal distances around the 
calyx. Interbrachial spaces somewhat depressed at their lower ends, and 
slightly receding between the arm bases; the first plate large, its upper half 
considerably wider than the lower half, its upper face truncate and somewhat 
concave. The plate of the second row is approximately as large as the first 
costals, but higher than wide and hexagonal; the lower lateral faces parallel, 
the upper lateral ones sloping. There are three plates in the third row, and 
others above. Interdistichals one. Structure of the ventral disk unknown. 
Horizon and Locality. — Upper Helderberg group; Falls of the Ohio. 
Type in the collection of Victor W. Lyon. 
