PLATE XV. 



Page 

 GiiBERTSOCKixus TLTBEROSus (Lyon and Cass) 239 



Fig. la. A large specimen showing the calycine appendages. 

 lb. Another specimen, showing the appendages and arms. 



GiLBERTsocEiNus DispANSus W. and Sp • • • 240 



2a. Ventral aspect of a specimen, with calycine appendages and arms preserved. 



2b. Dorsal aspect of the same specimen. 



2c. Lateral view of the calyx. 



2d. Ventral aspect of the same specimen. 



GiLBEETSOCEINUS SPINIGERUS (Hall) 247 



3a. The type specimen, dorsal aspect of the calyx. 

 3b. Lateral view of the same sf)ecimen. 

 3c. Ventral aspect of tlie same. 



GiLBERTSocKiNus STELLARis De Kon. and Le Hon 236 



4. Side view of a slightly enlarged specimen from Belgium. (In this species, 



and the succeeding one from England, the appendages are arranged in five 

 pairs of separate tubes ; differing from most of the American species, in 

 which those of adjoining interradii are coalesced for some distance beyond 

 the calyx.) 



GiLBERTsocRiNus CALCAEATus Phillips 236 



5. Figured to illustrate the differences in the structure of the genus between 



European and American forms. Mountain Limestone, England. 



Ehodocrixus Whitei Hall 223 



6a. Side view of a large and very perfect specimen. 

 6b. Dorsal aspect of same specimen. 



Khodocrixus Wachsmuthi Hall 222 



I. 



Anterior side of the calyx. 



(All the specimens are in the collection of Wachsmuth and Springer except 

 that illustrated by figs. 3a, b, c, which is in the Canada Survey IMuseum 

 at Ottawa.) 



