The Calceocrinidce. 395 



joints, from which point it is of nearly uniform size for the next ten. 

 Joints higher than wide. 



Lateral arms giving off long, slender, flattened pinnules from every 

 second joint, and identical in structure with those in C. furcillatus. 



Posterior arm similar in structure to the lateral, but having three 

 brachials before bifurcation takes place. 



Column composed of short joints, every alternate or second joint of 

 which is shorter than the others. 



Prom the Trenton formation, Ottawa, Canada. Named in 

 honor of W. E. Billings, Esq._, who collected the specimens. 

 Types in Mr. Billings^ collection. 



This species is readily distinguished by its anchylosed basal ; 



it also differs from C. fuixillatus and C. ritgosus in its anterior 



radial being broadest at its basal end instead of at the brachial 



end. 



Castocrinus articulo§us E. Billings. 



PL X., Fig. 4. 



Heterocrinus articulosus E. Billings, Geol. Rep. Canada, Dec. IV., 



p. 51. 

 Heterocrinus articulosus Wachsmuth and Springer, Rev. Palaeo- 



crinoidea, Pt. I., p. 70. 

 Valceocrinus (9) articulosus E. O. Ulrich, 14th Annual Rept. State 



Geol. Minn., p. 113. 



Surface punctate, like that of C. rugosus, from which it differs in the 

 very low and comparatively wide anterior radial, and from all the 

 others here considered in the anterior and lateral radials being more 

 nearly equal in size. The anterior basals have the same shape and size 

 as in C. rugosus ; lateral basals unknown. 



Of the anterior arms only the first brachial is preserved. The lower 

 bifurcation of the lateral arm gives off laterally compressed pinnules, 

 which are strong at their base and wide from without inward; these are 

 given off at the second, fifth, seventh, tenth, and fourteenth joints, be- 

 yond which point the division is imperfectly preserved. 



The type specimen is rather imperfect, but is distinctive enough to 

 prove it to be a good species. 



Type in the collection of the Museum of the Geological and 

 Natural History Survey of Canada. 



Castocrinus inaBqualls E. Billings. 

 PI. X.. Fig, 5. 



Heterocrinus incequalis E. Billings, Geol. Survey Canada, Decade IV., 

 p. 51. 



