626 THE CEINOIDEA CAMERATA OF NORTH AMERICA. 



nized. Anal tube very long and slender ; composed of small, transverse, 

 flat pieces. Column moderately thick ; the nodal joints long, a little project- 

 ing, and their outer edges slightly convex ; the axial canal large and sharply 

 pentangular. 



Horizon and Locality. — Upper Burlington limestone ; Burlington, Iowa. 



Type in the (Worthen) Illinois State Collection, Springfield. 



Eemarks. — This is a variable species, and the only one of the genus 

 surviving the Lower Burlington bed. The plates of the calyx vary from 

 scarcely convex to highly nodose ; specimens having the first kind of plates 

 were described as Actinocrinus glacis, and those with the latter as A. tholus. 

 Under Actinocrinus eryx Hall redescribed a third species, in which the arms 

 and anal tube were preserved, but unfortunately, in his photographic plates 

 of eleven years later, he confounded the specimen, which we have examined 

 in the Museum of Comparative Zoology, with Periechocrinus Whitei, a species 

 with branching arms, and without anal tube. 



TELEIOCRINUS W. and Sp. 



18S1. W. and Sp. ; Kevision Palaiocr., Part II., p. Ii6 (Proceed. Acad. Nat. Sci. Pliila., p. 320). 

 1889. S. A. Miller; North Amer. Geol. and Paleeont., p. 286. 



Syn. CalathocriHUs Hall ; 1861 (not yon Meyer 1848) in part ; Descr. New Palsoz. Crin., p. 12. 



Syn, Strotocriims (Section B) Meek and Woethen; Geol. Rep. Illinois, Vol. II., p. 190. 



A modified and extravagant form of Oactocrinus. Calyx obconical to the 

 base of the palmars, then spreading horizontal!}^, and forming a broad and 

 continuous rim around the calyx, from the outer margins of which the free 

 arms are given off to the sides. Ventral disk short, supporting a long, 

 nearly central anal tube. Ornamentation of the dorsal cup similar to that 

 of Actinocrinus and Oactocrinus, but somewhat coarser, and the nodes more 

 conspicuous than the striations, often obscuring the latter. Basals three, 

 large, massive, more or less projecting beyond the sides of the column. 

 Radials and costals generally as long as wide or longer, but the costals in 

 proportion considerably smaller. Distichals 1 X 10, all axillary, separating 

 the rays into two divisions (but not into lobes), which subdivide by alternate 

 bifurcation from every successive brachial to the last in the calyx, which 

 bears two simple arms. The successive orders of brachials of the two divi- 

 sions are very numerous ; they invariably consist of a single row of plates, 

 and in each order only the plate of one side bifurcates again ; the opposite 

 one is truncate, and is followed by a variable number of other plates of the 



