PLATE LIL. 
METACRINUS INTERRUPTUS, n. sp. 
Diam. 
. An entire specimen, . : : . nat. size 
. Portion of the stem, . ; : : . Bed. 4 
. Face of an internodal joint, . ; : soe AG 
WV. £.—The sides of this joint are somewhat more hollowed than is usually the case. 
. Upper face of a nodal joint, . : ; : ee are) 
. The termination of the ambulacrum on one of the small outer 
pinnules ; from the side, . ; , : ee ent) 
. Upper view of the ambulacral skeleton nearer the base of the 
pinnule, . : ; : : ; Seanad 
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