OKDKK III 



CRINOIDEA FISTULATA 



1 .V.) 



in,'/ nil 



.Inn* xi in I'lr "/' lifii n<-h hiy, /////>/W, inti r/W.v'/^/, "/' OGCOtivnotty 

 /Kiriii't /"/,'/' iiinniih's. Devonian and Carboniferous. 



Pott'i-i'"-rinit.^ Miller. Dorsal cup obconical; plates thin and plicated arolind 

 their margins so as to form triangular pits at the angles. IB equal ; B high.. 

 Three of the /.' hexagonal; the posterior and the right postero-lateral ones 



^c7 



FIG. 204. 



Diagram showing arrangement 

 of ]>lates in the dorsal cup of 

 Scaphioc ri n u s. 



Sniji/i me, -inn* it, i ('//.-., Hall. Sub- 

 Carboniferous (Keokuk (Jroup) ; 

 Crawfordsville, Indiana. Natural 

 si xi '. 



FIG. 



Diagram of '//"/'/"'''''" "'-' ''', '"- 

 frabasals ; ^, Basals ; r, Hadials ; 

 c, Anal ; br, Brachials (after 

 Bather). 



FIG. 2f.:,. 



Woodocrin UK MiKTmlnr. 

 tj/lus, de Kon. Perfect 

 specimen from the Car- 

 boniferous Limestone 

 of Yorkshire (after d 

 Koninck). 



heptagonal, and rising above the level of the others. 

 Articular facets crescent-shaped, and rarely occupy- 

 ing the full width of the plates. Anal and radianal 

 both present. Ventral sac very large, tubular, and 

 extending to the full length of the arms ; its two 

 lowermost plates partially incorporated into the sac. 

 Arms long, branching, composed of cuneate joints, 

 alternately arranged. Column round or obtusely 

 pentagonal. Upper Devonian and Sub-Carbon. 



Lophocrinus, v. Meyer. Devonian ; Nassau. 



Scaphiocrinus, Hall (Hydriocrinus, Trautsch.), 

 (Figs. 263, 264, 269). Dorsal cup low cup-shaped 

 to saucer-shaped. Arrangement of plates and mode of articulation as in the 

 preceding ; but the upper faces of the R form a horizontal line, and are 

 completely occupied by the lower faces of the first brachials. Costals one 

 or two ; the axillaries provided with transverse ridge and fossae similar to 



