ACTINOCRINID Z&. 599 
plates beautifully granulated. Interambulacral plates flat. Orals crowned 
with a small central tubercle, as are also the plates roofing the ambulacra, 
which are irregularly arranged, and decrease in size as they approach the 
arms. 
FHlorizon and Locality. — Lower Burlington limestone ; Lake Valiey, New 
Mexico. 
Type in the collection of Prof. Cope. 
Physetocrinus lobatus W. and Sp. (nov. spec.). 
Plate LXILL. Figs. Sa, b. 
Calyx proportionally higher than in the preceding species, height to 
width as ten to nine; distinctly lobed at the arm regions. Dorsal cup some- 
what bulging, slightly constricted across the distichals. Ventral disk almost 
flat; interradial and interdistichal spaces — the latter from near the summit 
of the disk to the second row of interbrachials — deeply grooved, giving to 
the surface of the tegmen, and to the upper part of the cup a sharply lobed 
outline. Ornamentation of the plates similar to that of P. Copei; but the 
ridges, as a rule, more prominent, the inner faces of the triangles deeper, 
and all enclosing a second triangle within the outer one. 
Basals moderately short, forming a cup with slightly projecting lower 
margin, and small notches at the sutures; axial canal small and pentangular. 
Radials and costals as long as wide, or a little longer; the first costal two 
thirds the size of the radials and hexangular, the second somewhat larger 
than the first, and heptangular. Distichals and palmars small, both even 
with the costals, but raised considerably above the interradial spaces. The 
distichals give off an arm to the outer sides of the rays, the palmars two 
arms, making six to the ray. Structure of the arms unknown. Regular 
interbrachials: 1, 2, 2,2; the anal plate followed by 2, 3, 3, 2 plates; the 
upper row at all sides in contact with the plates of the tegmen. Plates of 
the disk almost flat, small, and of uniform size; their arrangement irregular, 
except on approaching the arms, where they become alternate. Orals inde- 
terminable, and probably wanting. _ Anal regions slightly bulging, the open- 
ing directed anteriorly. 
Horizon and Locality. — Lower Burlington limestone; Lake Valley, 
New Mexico. 
Types in the collection of Wachsmuth and Springer. 
