THE 
AMERICAN GEOLOGIST 
Vol. XXIV. NOVEMBER, 1899. No. 5 
A NEW CYSTOCRINOIDEAN SPECIES FROM 
THE ORDOVICIAN. 
By F. W. Saedeson, University of Minnesota. 
(Plate XII.) 
In the Galena (Trenton) series of the Ordovician at Saint 
Paul. Minnesota, isolated large plates of a crinoid occur, which 
are striking objects to the collector of fossils. They have 
been found also at Ellsworth, Wisconsin. These plates are 
well ornamented, thick, and about one inch wide, — larger in 
fact than the whole calyx of any known associated crinoid. 
They occur in the zone called the Stictopora bed, associated 
with conglomerate and with concretionary or oolitic limonite 
in the clay-shale of this bed. The conglomerate is evidently 
a corrosion product, and it is probable therefore that this 
crinoid lived here only during periods of non-deposition of 
sediment. Its habitat was most probably near the oceanic 
litoral zone, among reefs, in shallow water. The character of 
the sediments and the nearness of the localities where it is 
found, to the supposed Ordovician shore line to the northward, 
accord with that theory. 
The isolated plates were at first identified as those of some 
large individual of Carabocrinus vancourtlandti Bill., a rare, 
and unfortunately, little known species from the Trenton stage 
of Canada. They belong, however, neither to Carabocrinus 
nor to the species C. vancourtlandti, but they are nearest that 
species. 
The species seems to be a more than ordinarily important 
