314 



PALAEOZOIC TIME CARBONIFEROUS AGE. 



Figs. 538, 539. 



39 /F^ 



face-markings of same; fig. 539, Spirifer biplicatus H., from Burlington and 



Quincy, Illinois; fig. 540, Orthis Michelini (var. Burlingtonensis H.), from 



the Burlington limestone; Orthis (Strepto- 



rhynchm) Umbraculum (fig. 550); fig. 541, Sp>i- 



rifer octoplicatus ; fig. 542, Sp. bisulcatus (in- 



zrebescens H.) ; fig. 543, Retzia Verneuilana H. ; 



fig. 544, Chonetes variolata A. d'Orbigny; fig. 



544 a, hinge-line of same, and aperture closed 



by a pseudo-deltidium ; fig. 545, Productus 



punctatus Martin ; also P. Flemingii Sowerby, 



P. elegans Norwood & Pratten, Spirifer in- 



o-assatus Eichwald, Sp. spinosus Norwood 



& Pratten, from the Kaskaskia limestone, etc. 



fined in Missouri to the lower Archimedes 



Brachiopods occur not only in the Subcarboniferous beds, but also in the Car 



boniferous. They are common also in Europe. 



538, 538 a, Chonetes ornata; 



539, Spirifer biplicatus. 



The Spirifer inerassatus is con- 

 limestone. Many of the other 



Fig. 540, Orthis Michelini, var. Burlingtonensis ; 541, Spirifer octoplicatus ; 542, Sp. bisul- 

 catus ; 543, Retzia Yerneuilana; 544, 544a, Chonetes variolata; 545, Productus punc- 

 tatus. 



There are also Gasteropods of the genera Platyceras, Straparollus, Naticopsis, 

 Pleurotomaria, Jfachrocheilus, Loxonema, etc. The Cephalopods are of the 

 genera Nautilus, Orthoceras, Gyroceras (the Gyroceras Burlingtonensis, from 

 Burlington, Iowa, five inches in diameter), Goniatites, etc. 



4. Articulates — A few Trilobites of the genus Phillipsia. 



5. Vertebrates. — Fishes of the Selachian genera Cochliodus, Cladodus, 

 Orodus, Carcharo])sis (Pristi cladodus), etc., besides others of the order of Ganoids. 

 Fig. 546 is a tooth (natural size) of Cochliodus nobilis Newberry & "Worthen, from 



