PLATE XVII. 



Page 

 GlLBEETSOCRIKUS KETICULATUS (Hall) 244 



Fig. hi. Dorsal aspect of tlie calyx. 



U. Lateral view of another specimen. 



GiLBEKTsocRiNus FiscELLUs (M. and W.) 245 



2a. Anterior view of calj-x. 

 21). Posterior view of same. 

 2c. Ventral aspect of same. 



2d. Posterior view of another specimen, in which the appendages next to the 

 posterior side separate within the calyx. 



GiLBEETSocRiNDS TExuiRADiATUs (M. and W.) 246 



.'5. Dorsal aspect of a crushed specimen, showing parts of the appendages. 



GiLBERTSocRixcs OBOVATUS (i\I. and W.) 241 



4(1. Side view of calyx. - 



■iO. Ventral aspect of same. (Figure drawn anal side up.) 



GiLBERTSOCEIXUS TUBERCULOSUS (Hall) 243 



;■) 7. A specimen with arms, appendages, and stem. 

 ;")/;. Ddrsal aspect of another specimen. 

 5t'. Ventral aspect of same. 



GiLBERTSOCEIXUS TUBEEOsus (Lyon and Cass) 239 



(i. Dorsal aspect of calyx. 



GiLBEETSOCRIXUS TTPUS (Hall) 242 



7«. A large specimen from the Upper Burlington Limestone. 

 7b. Portion of the arms, showing mode of bifurcation. 



(All specimens in the collection of Wachsmuth and Springer.) 



