FAUNA OF THE CARBONIFEROUS AGE. 



393 



Fig. 533. 



Fig. 532 a. 



Figs. 530-533.— Echinodekms op the Carboniferous Age— CHnid : 530. Zeacrinus elegans (after 

 Hall). Echinoids and Asteroids ; 531. Oligoporus nobilis, x J (after Meek). 532. a, Archseoci- 

 daris Wortheni (after Hall); b, Spine of same, natural size. 533. Onychaster flexilis (after Meek). 



also continue, but both may be said to pass out with this age, although 

 a few seem to pass into the Lower Triassic. 



__— PALAEOZ O IC -__ 



ilurian Devon 5 Carton if l - 



NEOZOIC 



STEM M EID 



Fig. 534.— Diagram showing General Distribution of Echinoderms in Time: Shaded portion, 



stemmed; unshaded, free. 



Trilobites and Eurypterids also continue ready to disappear at the 

 end, but an advance in the Crustacean class is observed in the intro- 



