ACTINOZOA. 



No. 469. Favistella stellata. Hall. 



Cincinnati Group, Nashville, Tenn. 



151 



No. 470. Favosites Emmonsi, Rom. 

 Corniferoiis, Clarke Co., Indiana. 



No. 471. Favosites. 



Polished specimen. Hamilton Group, Iowa City, Iowa. 



No. 472. Halysites catennlatus, Linn. 



This is the well known "chain-coral" so 

 characteristic of the Niagara Group. From 

 the Niaarara of Western New York. 



No. 473. Michelinia cylindrica, E. and H. 

 Coruiferous, Falls of the Ohio. 



No. 474. Monticulipora Dalei, E. and H. 

 Cincinnati Group, Cincinnati, Ohio. 



No. 475. Monticulipora mammilatus, d'Orb. 

 Cincinnati Group, Cincinnati, Ohio. 



ORDER RUG-OSA. 



This group lias no undoubted representatives to-day, and very 

 few in rocks of the later ages. It is preeminently a Palaeozoic or- 

 der, and includes the abundant and characteristic Cyathophyllidfe. 

 The members agree with Zoantharia in possessing a sclerodermic 

 skeleton, but differ in having the radiations of the body some 

 multiple of four. In the latter character they agree with the 

 Alcyonaria. 



