40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 76 



Plate 5 „. „ 



^ PAGE 



Synbathocrinus wachsmuthi Meek and Worthen 19 



Fig. I. A specimen showing the heavy arms, with the anal tube passing 

 up between them, distinguished by its smaller size and longer 

 ossicles. 



2. Posterior view of specimen with arms partly removed, showing 



the anal plate in position. X I- 



3. Lateral view of same, showing course of the tube plates following 



the anal ; for comparison with figures 4 and 5 of plate 3 ; it 

 shows also the ventral processes of the radials surmounted by 

 the pyramid of oral plates. X f • 



4. Fragment showing grooved anterior side of anal tube plates con- 



trasting in size and proportions with arm plates at same level. 



Xf. 



5. Ventral view of calyx ; showing the great thickening of the 



radials, their large muscle fossae, the groove leading to the 

 anal tube, and the linear openings of the dorsal canals. X 3 • 



6. Basal view of same, showing division of basals. X f • 



7. General aspect of a small specimen with complete arms. 



Mississippian Lower Burlington limestone; Burlington, Iowa. 



Synbathocrinus wortheni Hall 19 



8. A characteristic specimen from the Upper Burlington limestone ; 



Burlington, Iowa. 



Synbathocrinus dentatus Owen and Shumard 19 



9. A maximum specimen of this large species, with arms complete ; 



the anal tube, extending to nearly the full height of the arms, 

 is readily seen in the specimen lying close under the left pos- 

 terior arm, but is obscured by shadow in the figure. 

 ID. A very young specimen from the same layer, with arms con- 

 sisting of only about 10 brachials. 

 Mississippian, Upper Burlington limestone; Burlington, Iowa. 



Synbathocrinus robustus Shumard 19 



11. Ventral view of calyx showing thickened radials, wide arm facets, 



strong ventral processes, muscle fossae, groove at anal side, 

 and linear openings of dorsal canals. 



12. Basal view of another specimen. 



Mississippian, New Providence shale ; White's Creek, Ten- 

 nessee. 



Synbathocrinus hamiltonensis n. sp 29 



13. The holotype, showing radials deeply notched for the anal plate. 



14. Posterior view of calyx of same, showing the anal structures 



in better detail. X f • 



Middle Devonian, Hamilton; Bellona, New York. 



