226 



PALEOZOIC TIME. 



out, flower-like ; 430 shows the box-like body above, but wants the 

 arms. 



Figs. 429-431. 



Crinoids. — Fig. 429, Ichthyocrinus laevis ; 430, Caryocrinus oruatus; 431, a, b, c, Stephano- 



criuus angulatus. 



Some of the characteristic Brachiopods are represented, natural 

 size, in Figs. 432 to 444 — all very abundant species in the Niagara 

 limestone. The shell of a large Lamellibranch, from the upper part 



Fiss. 432-444. 



Bkaohiopods. — Fig. 432, Strophomena rhomboidalis ; 433, Leptasna transversalis ; 434, 435, 

 Atrypa nodostriata ; 436, Merista nitida; 437, Anastrophia interplicata ; 438, a, Rhynchonella 

 cuneata; 439, a, b, Leptocoelia disparilis ; 440, a, Orthis bilobus ; 441, 442, Spirifer Niagarensis ; 

 443, 444, Sp. sulcatus. 



of the Niagara group, is represented in Fig. 444 A. Another more 

 common kind, of the genus Avicula, is shown in Fig. 445, reduced 

 one half in breadth ; and Figs. 446, 447 represent two Niagara Gas- 

 teropods. 



