NIAGARA GROUP. 
113 
1. Ilypanthocrinites cjelatus. 
2. Hypanthocrinite3 deeorus. 
3 Hypanthocrinites deeorus. 
4. Marsupiocrinites (?) dactylus, 
1. Hypanthocrinites ccelatus, H.—Pelvic plates 5, hexagonal, equal in size, supporting on 
their upper edges five quadrangular costals, resting upon the superior lateral edges of the 
pelvic plates, are five large (nine-sided) intercostal plates. Each costal supports a nearly re¬ 
gular pentagonal scapular plate, resting upon the upper oblique lateral edges of which, and 
the intercostal plate are two pentagonal arm joints, and upon each one of these rests a some¬ 
what quadrangular hand-joint, which supports two fingers composed of thin plates joining in 
the centre by their cuneiform edges producing a longitudinal suture. Upon the superior edge 
of the intercostal plates rests a double, somewhat conical plate, supporting a longitudinal rib, 
which separates the pairs of arms and fingers. There is a similar single conical plate resting 
on the superior lateral edges of the arm joints, and supporting in like manner a longitudinal 
rib. These apparent ribs are partitions or dissepiments, which reach nearly to the centre, 
separating the internal part of the crinoid in ten cells or compartments. 
This species bears a close resemblance to the next, but differs from it in the following par¬ 
ticulars : The whole structure is smaller, the plates are covered with tubercles or tubercu- 
lated undulating lines ; the arms are deeply sculptured or corrugated, so as to render the su¬ 
ture almost invisible. The single conical plate supporting the rib is not truncated below, and 
Geol. 4th Dist. 
15 
