E'CHINODEKMATA OF THE BRASSFIELD FORMATION 
13 
are pentagonal in form, and there is no indication of the anal 
side in the part of the calyx known at present. Moreover, in 
the second species, (plate VI, figs. 2 A-D) the surface ornamen- 
tation consists of numerous parallel lines which are perpendic- 
ular to the adjacent sides. The surface of the first species appears 
to have been relatively smooth. 
At present there is no means of determining whether the coiled 
crinoid stems described here belong to either of these two species, 
but the latter are the only forms known of such size as to suggest 
the possibility of such a relationship. 
Dimerocrinus (?) vagans sp. nov. 
Plate II, figs, 6 A-E 
Basals five, four of them pentagonal in outline, the fifth trun- 
cated and supporting the anal x plate. The inner margin of 
the circle of five basals is formed by the aperture connecting 
the lumen of the stem with the body-cavity of the calyx. The 
articulating surface for the attachment of the column is formed 
by a circular ridge which encloses the proximal parts of the five 
basals. The area thus enclosed is deeply concave. The crest 
of the circular ridge traversing the basals is marked by numer- 
ous, very fine, short lines arranged as though radiating from the 
center of the circle. About 9 or 10 of these lines occur in a 
width of 1 mm. No infrabasals are present in any of the speci- 
mens found. In the specimen represented by figure 6 A the 
margin of the articulating surface appears to be slightly scal- 
lopped, somewhat as in figure 6D. If this could be confirmed 
by well preserved specimens it would indicate the former pres- 
ence of infrabasals. The presence of such infrabasals would 
relegate our specimens to the Dimerocrinidae. As a matter of 
fact, however, the former presence of infrabasals remains ex- 
tremely doubtful, in which case the calyces here described would 
not fit into any of the families of Crinoidea as now defined. Fig- 
ure 6D is intended to indicate the possible relationship of these 
calyces to the Dimerocrinidae. 
