PLATYCRINIDuE. 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 E. millehracliiatus, to which 

 it bears about tlie same relation as Steganocrinus araneolus to S. pentagonus. 



Horizon and Locality. — Burlington and Keokuk Transition bed, near 

 Burlington, Iowa, 



Ti/pes in the collection of Wachsmuth and Springer. 



Eucladocrinus montanensis Meek. 

 Plate LXXII. Fig. 5. 



1871. Meek ; Hayden's Kep. U. S. Geol. SurT, of Montana, p. 373. 



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 subqnadrangular, 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 ronnded at the dorsal side, biserial and pinnule-bearing. All 

 other parts of the species unknown. 



Horizon and Localitxj. — Subcarboniferous ; Montana (the exact locality 

 not being given). 



Ti/2)e in the Smithsonian Institution, No. 7805. 



Remarks. — This species probably resembles Eudadocrinus 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. 



