DISCOID CRINOIDAL ROOTS AND CAMAROCRINUS 241 



except that the column and root appear sharply defined at their 

 junction. 



In a Httle later publication/ James Hall presents conclusive evi- 

 dence of a fragment of Crinoidal stem attached to a discoid base. 

 The stem and therefore the base is identified as belonging to a par- 

 ticular species of Crinoidea, i. e., Calceocrinus (Cheirocrinus) clarus 

 (Hall). These fossils come from the Silurian Niagara group. The 

 base is similar to Fig. i and Figs. 6 and 7. Another base to which a 

 fragment of stem remains attached is described from the Ordovician 

 in the upper part of the Cincinnati group, at Cincinnati, Ohio, by 

 F. B. Meek.^ He says that it probably belongs to Anomalocrinus 

 incurvus M. & W. It "consists of a soHd expansion near an inch 

 in diameter, with irregular margins." "It has a short piece of the 

 column attached, which rises abruptly from the expansion, and is 

 composed of very thin anchylosed segments, showing the appearance 

 of being each made up of numerous little pieces, . . . . " i. e., like 

 stems of A . incurvus M. & W. Fig. 4 and 5 here are drawn after his 

 figures 6 d, c. 



Wachsmuth and Springer,^ say that "in the Hudson River group 

 of Cincinnati, we occasionally find Crinoidal disks attached to pieces 

 of coral, which closely resemble the dorso-central of Antedon. These 

 disks have a pit or depression at the middle of the upper face, some- 

 times inclosing a small stem joint. They are irregularly round, and 

 some of them have small processes passing outward from the sides 

 which seem to represent primitive cirri (Plate I, Figs. 9, 10)." Draw- 

 ings after their Figs. 9, 10, are given here in Figs. 6, 7. Opposite 

 Plate I, in the description to Figs. 9, 10, they say "dorso-central plates, 

 supposed to belong to a species of Heterocrinus.'" Wachsmuth and 

 Springer consider the roots as having separated from the stem during 

 the life of the Crinoid. 



In a former paper on "A New Cystocrinoidean Species from the 

 Ordovician,"'* I have described a few specimens of discoid roots 

 which were found associated with Strophocrinus dicyclicus Sar., 



1 Fifteenth Rep. N. Y. State. Cab. Nat. Hist., PI. I, Figs. 17, 18, 1862. 



2 Geol. Siir. Ohio, Vol. I, "Paleontology," p. 18, PI. II, Fig. 6, d, e, 1873. 



3 Op. cit., p. 49. 



'^American Geologist, Vol. XXIV, pp. 263-76, 1899. 



