MELOCRINID. 277 
arranged in one of the specimens: 1, 2, 3, 3, 3, 3, 5,3, 4,4; the latter: 
1, 2, 3, 3, 3, ete. The anal side contains three plates in the second row, and 
there are other extra plates above. Nothing is known of the ventral disk or 
anal opening. Column sharply pentangular ; the nodal joints the longest, their 
edges flattened (not convex); internodal joints short and angular in the 
upper part of the stem, but gradually growing as large as the nodal ones; 
axial canal wide and slightly pentalobate, the lobes disposed radially, in the 
same direction as the outer angles of the stem. 
Forizon and Locality. — Upper part of the Hudson River group; at Mor- 
row and Waynesville, O. 
Types in the collection of Mr. F. L. Fornshell. 
Remarks. —\t is with some hesitation that we place this species under 
Glyptocrinus. It differs from all other species of the genus in the pentangular 
stem, and the radial position of its axial canal, a feature in which it is at 
variance with all other known monocyclic Palzocrinoids. That it actually 
has no infrabasals, we ascertained from a fragmentary specimen by exposing 
the inner floor of the basal cup. It has in the centre a large pentangular 
open space, whose angles are pointed to the interbasal sutures, taking the 
same direction as the angles of the stem. A somewhat similar departure 
from the rule is claimed to exist in the recent genus Pentacrinus, in which, 
however, stem and canal are dvterradial. 
PERIGLYPTOCRINUS W. and Sp. (nov. gen.). 
Closely allied to Glyptocrinus, but having larger basals and well developed 
biserial arms; the arms of Glyptocrimus being described by all writers as uni- 
serial. The only two species known to us are our new species Periylypto- 
crinus Billingsi, which we make the type of that genus, and P. priscus, which 
was described by E. Billings as a Glyptocrinus. Fragments of a third species 
are found in Alexander County, IIls. 
Distribution. — Black River shale, and Trenton limestone of Canada, 
Periglyptocrinus Billingsi W. and Sp. (nov. sp.). 
Plate XXI. Figs. 1a, 6. 
A beautiful and highly ornamented species. Dorsal cup elongate-obcon- 
ical, higher than wide, somewhat depressed at the interradial and interdis- 
