PLATE LXIX. 



Pack 

 Platyckixus stjimetriccs W. and Sp 655 



Fig. la. Specimen with anus aud column. 



1/>. Ventral aspect of the calyx ; a large specimen. 



Ir. Ventral aspect of a young si^ecimen ; the orals almost symmetrical. 



' Platycrinus plaxus 0. and Sh 608 



2'i. A large specimen with arms. 



2//. Lateral view of the dorsal cup. 



2c. A portion of the arms enlarged. 



2d. A young specimen, apparently of this species. 



Platycrinus burlingtonensis 0. aud Sh 653 



3a. A medium sized specimen with arms. (After Meek and Worthen.) 



Sh. Lateral view of a large calyx. 



3r. Ventral aspect of another large specimen, showing the anal tube. 



3d. Posterior view of-a smaller specimen. 



3e. Ventral aspect of another small sjiecimen. 



3/ Dorsal cup of a young specimen. (Inadvertently drawn with left antero- 

 lateral interradius at the top.) 



o'j. A very young specimen with zigzag arms, composed of single joints. 



3/*. Portion of an arm showing the lateral processes (enlarged). 



3/. Portion of an arm in a dorsal aspect (enlarged). 



Platy'ckixus Agassizi W. and Sj) 669 



4. A very large specimen with arms. 



Platycrinus pileiformis Hall 656 



5. A specimen with arms (slightly restored). 



Platycrinus boncexsis White 083 



6. A specimen having six arms to the ray. 



Platy-crixus sar.e Hall 677 



7. The type specimen. (After Hall.) Somewhat flattened. 



(All specimens in the collection of Wachsmuth and Springer, except that of 3-7, 

 which is in the Museum of Comparative Zoology, and Fig. 7, which is in the 

 Illinois State iMuseum.) 



