Plate (i. 



DOLATOCRINUS ORNATIIS Meek 



Fig. 1. Basal view of the typo, having small radial ridge. Columbia Uni- 

 versity, New York. 



2. Tegmen of another specimen, covered with small tubercles. 



3. Basal view of larger specimen, without any radial ridge. 



4. Lateral view of same, showing tubercles on tegmen, and projecting lip 



at the edge. 



Onondaga: Columbus, Ohio. 



DOLATOCRINUS ASPERATUS Miller and Gurley 



5, 6, 7. Basal, lateral, and tegmenal views of the type, showing radial 

 ridge formed of connected nodes. University of Chicago, No. 6071. 



8. A larger specimen, with large disconnected nodes and pitted surface 



ornament. 



9. Large specimen with radial ridge not well defined; coarse pustules and 



small nodes more or less radiately arranged, tending to form geomet- 

 rical figures. 



10. Large specimen with narrow radial ridge limited to primibrachs; fine 



striae forming triangles. 



11. Lateral \'iew of specimen with continuous ridge extending to arms; 



fine striate ornament. Type of D. marshi, var. hnmiltonensisV\'a.chs- 

 mut and Springer. 



12. Basal view of similar specimen, showing continuous ridge. 



Among these six specimens, all having the same general form and 

 proportions and 10 arms, are four different kinds of radial ridge, and 

 three styles of surface ornament. 

 Hamilton: Louisville area. 



DOLATOCRINUS, species 16 



13. The tegmen of one of the few known specimens having parts of the 

 arms and pinnules attached; it is imbedded, and the dorsal parts 

 parts can not be seen. 



Hamilton: Louisville area. 



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