PLATE LXXVII. 



Page 

 DicnocRiNus poLYDACTYLus Cass. aiid Lyon 750 



la. A large specimen with arms. 



lb. Posterior view of calyx, showing the elevated dome and disk ambulacra. 



DiCHocKixirs LACHRYMOsus Hall 754 



2a. Specimen witli arms and stem. 

 2b. Posterior view of calyx. 

 2c. Ventral aspect of same. 



DiCHOCEINUS LIRATUS Hall 759 



3n. Specimen sliowing the arms and stem. 

 3b. Posterior view of the dorsal cup. 



DiCHocRiNus ciNCTUs Miller and Gurley 704 



4rt. Posterior view of specimen with arms. 

 4b. Ventral aspect of the calyx. 

 4c. Distal face of first distichal (f ). 



DiciiocRiNus PLicATus Hall 758 



5a. A small specimen with arms and stem. 



5b. Another specimen, giving a side view of the dorsal cup. 



DiCHOCEINUS ORNATUs W. and Sp 7G2 



6. Specimen with arms and stem, from near Mt. Pleasant, Iowa. 



DicHocRiNus l;evis Hall 7G5 



7a. Specimen with arms. (Coll. Mr. Fultz of Burlington.) 



7b. Another specimen. (Same collection.) 



7c. Portion of an arm with pinnules (enlarged). 



DicHOCRiNus ovATus 0. and Sh. 760 



8rt. A specimen with arms. 



Sb. Posterior view of the dorsal cup. 



DicnocRiNus OBLONGu's W. and Sp 7.">0 



9. Posterior view of the t^'pe specimen. 



