56 



SMITHSONIAN INSTITUTION 



PLATE XXV 

 (All figures natural size except where otherwise stated) 



PAGE 



Figs. 1-6. Forbesiocrinus agassizi Hall 250 



(Also on Plates XXI, XXVI) 



Fig. I. The type, anterior view. Now in the Hall Collection, University of Chicago. 



2. A very large specimen, slightly flattened, with fhe normal number of 3 IIBr. Posterior 

 view, showing plates of the anal interradius, filled with solid plates to the height of 

 IIIBr 2 or 3, in perfect sutural connection with the plates of adjacent rays; and the 

 sinuate sutures, with patelloid processes, throughout the rays. Author's collection. 



2,a. Flattened specimen with calyx plate somewhat displaced, anterior view. Shows character- 

 istic gibbosity of plates. Author's collection. 



3&. Left posterior view of same, showing sutural connection of post. B with succeeding plates. 



3(7. Detail of left anterior ray, showing sutural faces of R and IBn. X 2. 



4. A large specimen of the type of var. giganteus M. and W., with 4 IIBr in three rays, and 

 3 IIBr in the others; somewhat flattened; left anterior view. Shows the extremely 

 sinuate sutures throughout rays and arms, and patelloid projections on proximal face 

 of separated brachials ; also how the interbrachial plates run to an apex high up 

 between the rays. Author's collection. 



5a-6g. A series of specimens showing the markings upon the articulating and sutural faces of 

 various plates. All in author's collection. 



5a. Basal and radial plates from a single disintegrated specimen, dorsal view ; used in the next 

 following figures. 



5&. Proximal face of basal. X 2. 



Sc. Distal sloping face of basal at basi-radial suture. X 2. 



Sd. Proximal faces of radial. X 2. 



Se. Distal face of same. X 2. 



5/. Lateral face of radial. X 2. 



6a-6g. Plates from another specimen. All X 2. 



6a, b. Proximal and distal faces of axillary IBr2^IAx. 



6c, d. Proximal and distal faces of IIBr. 



6e. Left lateral face of same. 



6f. Lateral face of interbrachial iBr. 



6g. Dorsal view of same. 



Upper Burlington limestone ; Lower Carboniferous. Burlington, Iowa ; Washington 

 County, Indiana. 



