178 University Geological Survey of Kansas. 



Ceriocrinus craigi, (p. 32.) 



9. Base of calyx. Natural size. 

 96. Side view of same. 



Phlalocrinus magnificus, (p. 36.) 



10. Side view of specimen, showing calyx, arms, and anal tube. Natural size. 



PLATE VII. 



Erisoer'mus megalobrachius, (p. 37.) 



la. View of base of type. Natural size. 



16. Side view of same. 

 Ceriocrinus? monticitfatus, (p. 33.) 



2. Side view of type. Natural size. 

 Oligoporus? minutus, (p. 49.) 



3. Apical? view. Natural size. Type. 

 Jlydreionocrinus kansasensis, (p. 42.) 



4 to 7. Showing structure and appearance of various parts. (After Weller.) 

 H. subsinuatus. See plate VIII. 



PLATE VIII. 



Orbiculoidea missouriensis, (p. 55.) 



1 and 16. Upper and lower aspects of the flat valve. Enlarged. 



lc. Convex valve as seen from above. Enlarged. 

 Orbiculoidea manhattanensis. (p. 56.) 



2. Internal appearance of the flat valve, showing the peripheral ridge. Nat- 



ural size. 

 26. Convex valve. Enlarged. 

 Orbiculoidea convexa, (p. 55.) 



3. Convex valve. About natural size. 



36. Flat valve, perhaps of this species, internal view. Natural size. 

 Crania modesta, (p. 57.) 



4. Upper view of specimen on a smooth shell. Natural size. 

 Lingula mytiloides, (p. 54.) 



5. Specimen. Natural size. 

 Archceocldaris agassizi, (p. 48.) 



6 to 6c. Illustrations of plates and spines. 

 6e cross-section of 6d. All natural size. (After Hall.) 

 Archwocidaris mcgastylus, (p. 49.) 



7. Mass of spines and plates. (After Keyes.) ; 

 Derby a bennetti, (p. 59.) 



8. View of brachial valve. 

 86. View of hinge area. 



8c. Lateral view of specimen. (All after Hall.) 

 Archceocidaris trudifer, (p. 47.) 



10. Spine. Natural size. (After White.) 



