PLATE LXXVI. 



P.»'.E 



Arthkacaxtiia itiiacensis Williams 749 



Fig. la. Lateral view of a specimen with arms. (^Museum Cornell University.) 

 lb. Basal disk. 

 Ic. The movable spines upon the tegmen. 



Aethracantiia punctobeachiata Williams 7.50 



2a. Specimen showing spine bases. (Coll. W. and Sp.) 



2b. Another specimen with some sj)ines attached. (Coll. Prof. S. Calvin.) 



Aethracantiia depkessa W. and Sp 7.'51 



3a. Dorsal aspect of the type specimen. (Coll. W. and Sp.) 

 3b. Ventral aspect of the same specimen. 



DiciiocRixus LINEATUS Meek and Worthen 701 



4rt. The type specimen ; posterior view of the calyx. (Mus. Comp. Zool.) 

 45. Anterior view of the same specimen. 

 4c. Dorsal aspect of same. 



DiceocEiNus pisuM Meek and Worthen 763 



5. Specimen with arms. (Mus. Comj). Zool.) 



DiCHOCEiNUS CRAssiTESTfs White 709 



6a. The type specimen ; the anterior side exposed. (Same collection.) 



6b. Another specimen with part of the column attached. (Coll. W. and Sp.) 



6f. Posterior view of the calyx and anal tube. (Same collection.) 



DiCHOCRiNUS ovATUs Owen and Shumard 760 



7. A fine specimen with arms. (Mus. Couip. Zool.) 



DiCHOCRINUS LIRATUS Hall "iJO 



8. Specimen with arms and part of column. (Same collection.) 



DicnocRiNus coxANUs Worthen "OS 



9. The type specimen. (Coll. L. A. Cox.) 



DiCHocRiNus iiAMiLTONENsis Wortheu '•- 



10. The type specimen. (Same collection.) 



