PLATYCRINID&. 723 
almost flat, and covered with indistinct nodes; while the radials, which are 
wider than long, are entirely smooth. The calycine appendages, which in 
one of them are preserved to the distal end, bear but thirteen arms in the 
largest specimen, which are proportionally rather widely separated. In all 
other respects, the form in question agrees with XH. millebrachiatus, to which 
it bears about the same relation as Sleganocrinus araneolus to S. pentagonus. 
Horizon and Locality. — Burlington and Keokuk Transition bed, near 
Burlington, Iowa, 
Types in the collection of Wachsmuth and Springer. 
Eucladocrinus montanensis Meex. 
Plate LXXIL. Fig. 6. 
1871. Merrx; Hayden’s Rep. U. 8. Geol. Surv. of Montana, p. 378. 
Dorsal cup apparently subovoid, a little higher than wide, widest at the 
arm bases. Surface of plates smooth. Base basin-shaped, forming nearly one 
third the height of the dorsal cup. Radials subquadrangular, a little longer 
than wide, slightly spreading ; the lower face a little convex; the upper 
angles somewhat truncated. Facets moderately deep, their width about 
equal to the width of the radials. Costals very short, supporting two rather 
slender appendages, composed of numerous brachials of successive orders, 
of two plates each, which from the second plate respectively give off the 
arms. Arms rounded at the dorsal side, biserial and pinnule-bearing. All 
other parts of the species unknown. 
Florizon and Locality. —Subcarboniferous ; Montana (the exact locality 
not being given). 
Type in the Smithsonian Institution, No. 7805. — 
Remarks. — This species probably resembles Hucladocrinus millebrachiatus 
W. and Sp.; but the plates are not ornamented, the appendages seem to 
have been more slender and erect. It was described from a single very 
imperfect specimen, in which the base is badly distorted, and only small 
portions of the calycine appendages are preserved; these, however, show the 
structural peculiarities of the genus, while the specimen is too imperfect to 
admit of an accurate specific description. 
Se 
