314 



PALAEOZOIC TIME — CARBONIFEROUS AGE. 



Figs. 538, 539. 



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

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

 the Burlington limestone; Orthis (Strepto- 

 rhynchus) Umbraculum (fig. 550); fig. 541, Spi- 

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

 crebescens II.) ; fig. 543, Retzia Verneuilana II. ; 

 fig. 544, Ghonetes 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- 

 crassatus 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 incrassatus is con- 

 limestone. Most of the other 



Fijrs. 540-545. 



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

 catus; 543, Retzia Verneuilana ; 544, 544 a, Chonetes vai'iolata; 545, Productus punc- 

 tatus. 



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

 Pleurotomaria, JIachrocheilus, 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, Gladodus, 

 Orodus, Carcharo2>sis (Pristicladodus), etc., besides others of the order of Ganoids. 

 Fig. 546 is a tooth (natural size) of Cochliodus nobilis, from Illinois. This fish is 



