440 
Aug. F. Foerste 
State Museum, by figure 12 on plate 6; which is reprinted as figure 4 
on plate 6 of this Bulletin. The papillae on this stroma are 
largest nearer the margin of the theca, becoming smaller in the 
interambulacral spaces and on the lower parts of the covering 
plates. The ambulacra, mouth, and anal passage apparently 
were not obstructed, or at least were only partially obstructed. 
The anus is located in the center of the posterior interambulacral 
area, the papillate stroma constricting the passage and rising 
slightly around it. This suggests that the Dermatostroma spread 
over the theca during the life of the animal. The peristomial 
plates consist of a broad posterior plate and of two diagonally 
rhomboid anterior plates, as in Agelacrinus pileus. The upper 
margin of the posterior plate, as viewed from above, is broadly 
V-shaped and an angulation probably extended along its median 
line. 
As far as may be determined, through the covering papillate 
stroma, the upper plates of the marginal series and the interam- 
bulacral plates corresponded in size and form to those of Agela- 
crinus pileus, and it is to this species that the Clays Ferry Agela- 
crinus is most closely related. 
Theca very depressed convex, circular in outline, 12 mm. in 
diameter and about 2 mm. in height at the junction of the rays. 
Rays moderately curved, four sinistral and one dextral. Four of 
the interambulacral areas at present are depressed but this depres- 
sion evidently took place after the death of the animal. The ante- 
rior rays meet the marginal rim at angles varying from 30 to 50 
degrees. The left posterior ray meets the rim at an angle of about 
70 degrees and the right posterior ray forms an angle of about 30 
degrees. The tips of none of the rays are extended parallel to the 
peripheral ring, as in Agelacrinus cincinnatiensis, and as also to 
some extent in A. pileus. 
The most characteristic feature of this Clays Ferry species is 
presented by the lateral covering plates. The ambulacral rays 
apparently were somewhat elevated as in A. pileus. The lateral 
covering plates on opposite sides of the ray alternate with each 
other as in other species of this group. Along the upper surface 
of the rays, however, they appear like a series of short ridges 
arranged transversely to the length of the rays. In their narrow- 
ness and length these lateral covering plates differ conspicuously 
from those of Agelacrinus pileus, in which these plates are 
