460 
Aug. F. Foerste 
plates 11-17 was detected only after their presence had been dis- 
covered on other specimens on which the surface of these plates 
was well preserved. A small fragment, probably belonging to 
plate 13, is drawn in this analysis as though a part of plate 14. 
This is the fragment drawn by Meek, in his diagram of this speci- 
men, printed on one of the pages interleaved between the index 
and the numbered plates, at the close of vol. i, of the Paleontology 
of Ohio, in 1873, as though it were a fifth plate in contact with the 
anal area. 
The anal area is composed of two circles of plates, of which the 
type preserves only three plates belonging to the lower part of the 
outer circle. The two plates in contact with plate 7 are pent- 
agonal and bear a central tubercle, as described by Meek. A third 
plate, of a similar character, is in contact with plate 14. Judging 
from other specimens, the so-called central tubercle, on each of 
the three lower plates of the anal area may be regarded merely as 
a continuation of the parallel line ornamentation belonging to the 
top of plates 7 and 8. From other specimens it is known that the 
plates forming the top and upper left hand sides of the outer 
circlet of plates, in the anal area, are of much smaller size than the 
lower plates, thus reducing the width of the upper part of the outer 
circlet. The two plates indicated in the upper part of the anal 
circle therefore are incorrect, and should be replaced by a row of 
much smaller plates. 
The ambulacral arms are clearly outlined. Those parts of the 
thecal plates upon which they rest are flattened, but not indented 
or depressed. The arms or ambulacra are longer, more linear, 
and narrower at their proximal extremities than indicated by 
Meek’s Figure, 4c. Ambulacral plates with facets for attachment 
of the brachioles at alternate sutures of the ambulacral plates. 
At these areas of attachment the two adjacent plates form a single 
rounded low knob, projecting beyond the lateral contour of that 
part of the plates which intervenes between the points of attach- 
ment for the brachioles. The side of each knob is impressed by a 
single facet. Ambulacralia present but not clearly defined. 
In the museum at Earlham College, there is a second specimen 
of Lepadocystis, apparently from the same locality and horizon 
as the type of Lepadocystis moorei — namely, from the Whitewater 
member of the Richmond, at Richmond, Indiana. It differs in 
its smaller size, and in the surface ornamentation being more 
