234 PROCEEDINGS OF THE ACADEMY OF [1881. 



1S44. Coccocr. rosaceus F. Rocmer. fPlatycr. rosaceus) Rhein. Uebergangsgeb., 



p. 03, PI. 3, fig. 3 ; Miiller, 1855. Cocooor. rosaceus, type of the genus. Verb. 



Naturh. Verein Rhcinl., xii, p. 21, PI. 7, figs. 5 a, b, c Bronn, 1860. 



Klasscn des Thierreiohs, ii, PI. 28, figs. 8 a, b, c ; Schultze, 1867. Echinod. 



Eifi. Kalk., p. 89, PI. 12, fig. 13. Devonian, Eifel., Germany. 

 1860. Coccocrinus bacca F. Roomer. Silur. Faun. West. Tenn., p. 51, PI. 4, figs. 5 a, 



b, c. Niagara Gr., Tennessee. 



2. CORDYLOCRINUS Angelin. 



1878. Angelin. Icon. Crin, Suec, p. 3. 



1879. Zittel. Handb. der Palaeoutologie, i, p. 365. 



Syn. Plntycrinus Hall (not Miller), Pal. N. Y., iii, p. 113. 



Hall (Pal. New York, iii) describes three species under Platy- 

 vrinus which evidently belong to Cordylocrinus. TUey have the 

 same number of radials, and the arms are similarly composed of 

 a single row of joints. The genus should, however, be amended 

 so as to admit species with branching arms. We propose the fol- 

 lowing : 



Genei'ic Diagnosis. — Body small, closely resembling a young 

 Platycrinus. 



Basals three ; unequal, closely anchylosed. Radials 3X5: 

 the first very large ; the second quadrangular, much wider than 

 high, resting within the concave upper margin of the first; 

 the third, which has the proportions of the second, but bifurcating, 

 supports the two primary arms of which each ray is composed. 



Arms simple or branching, composed of single joints. Pinnules 

 long. 



Interradials, one between the upper edges of the first radials, 

 and followed by three or more similar plates in the dome, the 

 number of the latter being greater on the posterior side. 



Form of dome and anus, and condition of the apical dome 

 plates unknown. 



Column cylindrical, joints alternating in size, the larger giving 

 off sometimes at intervals long lateral cirrhi. 



Geological Position, etc. — Restricted to the Upper Silurian, both 

 in Europe and America. 



We place here the following species : — 



1878. Cordylocrinus comtus, Angelin. Type of the genus. Iconog. Crin. Suec, 

 p. 3, PI. 23, fig. 3. Upper Silurian. Gothland, Sweden. 



*1S61. Cordylocrinus parvus, Hall. (Platycr. parvus). Pal. New York, iii, p. 114, 

 PI. 4, figs. 6, 7, 8, 9. Lower Helderberg. Herkimer Co., New York. 



