Siluric Cystoidca and C dinar dcrfnus. — ScJiuchcrt. 237 
Column slender, but its length is unknown. 
Comparisons. — This species is readily distinguished from 
all other Pscudocrinites by the strongly stellate sculpturing of 
the plates. P. gordoni differs further in having many more 
brachioles. 
Formation and locality. — Of this species 3 specimens are 
in the U. S. National Museum, 7 in Mr. Hartley's collection 
and 2 in Mr. Gordon's. All are from the quarries near Keyser, 
West Virginia. 
Cat. number 35,069, U. S. N. M. 
Pseudocrinites clarki n. sp. 
Length of largest theca 44 mm., greatest width 30 mm., 
depth 22 mm. Length of an average specimen 30 mm., great- 
est width 22 mm., depth about 16 mm. 
Ambulacra in mature specimens very prominent, triangular 
in transverse section, extending around the entire periphery of 
the theca and touching the column. In the second largest in- 
dividual each ambulacrum has about 44 brachioles, but in an- 
other mature specimen there are only 32. Brachioles unknown, 
but apparently more slender than in P. gordoni. Ambulacral 
grooves narrow and covered by highly elevated ambulacralia of 
about the same nature as in P. gordoni, but less numerous and 
the larger plates more nodose. 
Basal pectinirhomb in the specimen of average size above 
mentioned, with about 42 dichopores, the one of plates 12 and 
18 with about 50, and the one of plates 14 and 15, which is the 
largest, with about 68. In the largest specimen there are as 
many as 120 in a rhomb. 
Hydropore minute and closely adjoining the rather large 
and prominent madreporite situated as usual in Pscudocrinites 
laterally between the ambulacra on the edge of plate 18. 
Anal area well marked, consisting of two circles of plates 
The outer circle has four small plates in the right-posterior 
corner and these are followed on the left by three very much 
smaller pieces. The latter are not readily seen and the first 
impression is that the four pieces of the right-posterior corner 
and plate 13 complete the circle. The prominent anal pyramid 
has 7 triangular pieces. 
Column stout, composed of thick pieces near the theca. 
Length unknown. 
