198 
PALAEONTOLOGY OF NEW-YOBK. 
pelvic plates. The plates in the fingers of Lyriocrinus interlock somewhat more deeply, 
and have a greater lateral extension and smoother surface than those of Glyptaster, 
while the fingers themselves diminish more rapidly towards the extremities. From all 
the other species of this period, this is readily distinguished on careful comparison. I am 
the more particular in calling attention to the less conspicuous parts, since, in the larger 
number of specimens seen, the structure of the cup is obscure, and it may not be readily 
compared with the figures given on the plate. Many specimens have no portion of the 
column remaining, and they appear like a globular sac with the simple terete arms 
spreading above. The column is more like the column of Eucalyptocrinus than any 
other species; but the proportional thickness of the joints is less, and the projecting 
edges of the alternate joints are much thinner. 
Fig. 1 a. An individual of medium size, preserving the cup and the arms nearly to their extremities. 
The structure is more clearly shown in this specimen, than in any other examined. Several 
of the arms remain imbedded in shale, and partly broken off. 
Fig. 1 5. A smaller specimen, preserving a portion of the column, and leaving four of the arms only 
visible : the specimen is imbedded in shale. 
Fig. 1 c. A larger specimen, showing the arms and column well preserved. 
Fig. 1 d. The structure as made out from the specimen fig. 1 a. The commencement of three pairs of 
fingers is shown, and the simple joints at the base of the other pahs in the same relative 
position. 
Fig. 1 e. A single plate enlarged, showing the character of the surface, and the increased ornament at 
the margins or junction with adjoining plates. 
Fig. 1 /. A fragment of a' column enlarged, showing more distinctly the alternating larger and smaller 
joints. 
Fig. 1 g. The end of the column enlarged. 
Position and locality. In the shale at Lockport. 
