66 SMITHSONIAN INSTITUTION 



PLATE XXX 

 (All figures natural size except where otherwise stated) 



PACE 



Figs. I, 2. Forbesiocrinus greenei Miller and Gurley 258 



Fig. I. The type, posterior view. Shows the relative flatness of the plates, little depression of 

 interbrachial areas, and their great vertical extent. University of Chicago. 

 2a. Another specimen from the same locality, from right posterior interradius ; showing the 

 rays to the third bifurcation, with iBr plates extending still higher up. Author's 

 collection. 

 26. Basal view of same. The IBB have been detached, having been fused with the top 

 columnal. 



Keokuk Gr. ; Lower Carboniferous. Edwardsville, Indiana. 



Figs. 3-17. Forbesiocrinus saffordi Hall 259 



(Also on Plates XXI and XXXI) 



A series of specimens to show the structures at the inner floor of the calj'x, especially the 

 form and course of the axial cords passing down into the column. Some are detached bases 

 with one or more columnals in position, and some are proximal parts of stem with infrabasals 

 fused to the top ossicle. Note that the small infrabasal, except in fig. 10, is at the anterior side 

 instead of right posterior as usual in the group. The central part of the infrabasals is occupied 

 by a large, tri-lobate funnel coinciding in position with them, and converging toward the 

 axial opening; the channels in the radial lobe and one of the others each divide by a septum 

 into two, producing with the third five channels downward into the stem, interradially disposed. 

 Fig. 3n. Calyx with RR attached, dorsal view, X 2 ; 3&, ventral view, X 2 ; 3(7, interior of IBB, 

 showing funnel, septa, and channels. X 4- 

 4a. Stem with fused IBB only, dorsal view, X 2 ; 4&, ventral view, X 2 ; BB mostly re- 

 moved, showing full size of IBB, and how small a part of them is exposed at the 

 interior. 

 50. IBB and BB with very thin upper stem ossicle attached, and sutures of IBB appearing 

 faintly through it, showing their size exteriorly equal to the column, dorsal view, 

 X2; S&, ventral view, showing the much smaller part of IBB exposed at the inner 

 floor, X 2; Sc, interior surface of IBB, X 4- 

 6a. IBB and BB with columnal, dorsal view, natural size ; 6b, ventral view, natural ; 6c, IBB, 



interior, X 4- 

 Ja. Ventral view of calyx with RR attached, showing articulating faces, X 2 ; yb, internal 



surface of IBB, X 4. 

 8, 9. Specimens showing calyx with RR, and top stem ossicle attached. 



10. Calyx with RR, showing surface of articulation, and of union with iBr; ventral view, 



funnel but little preserved. 



11. IBB only; funnel not preserved. 



12. 13, 14. Distal view of stems at various distances from the caly.x, showing forms of axial 



opening. X 2. 



15. Proximal part of stem, with IBB fused to top ossicle, some BB attached; lateral view. 



16. Proximal part of stem with IBB and some BB attached, showing extreme thinness of the 



columnals. X 2. 



17. Specimen with post. B angular; from same locality, probably of another species; dorsal 



view. 



Warsaw limestone ; Lower Carboniferous. Spergen Hill, Indiana. 

 All specimens figured on this plate are in the author's collection unless otherwise 



stated. 



