CARBONIFEROUS AGE. 



333 



Lamellibranchs were of many kinds. Two are shown in Figs. 651, 

 652. 



The following are figures of some of the Gasteropods, one excepted, 



Figs. 653-657. 

 655 



Gasteropods. — Fig. 653, Pleurotomaria tabulata ; 654, Bellerophon carbonarius ; 655, Pleuroto- 

 maria sphaerulata; 656, Macrocheilus (?) fusiformis; 657, Dentalium obsoletum. 



Figs. 658 



Fig. 661. 



Fig. 658, Pupa vetusta ( x % ) 

 659, P. Vermilionensis ; 660 

 Dawsonella Meeki. 



Spirorbis 

 carbonarius. 



Fig. 654 representing a floating shell of the old Lower Silurian genus 

 Bellerophon, of the tribe of Heteropods. 



One of the small land-snails, or Pulmonates, 

 is represented, a little enlarged, in 

 Fig. 658, — a species found in the 

 Nova Scotia Coal-measures ; and 

 Figs. 659, 660, show the forms of 

 two others, from the Carboniferous 

 of Illinois. 



Among Articulates, the con- 

 tinental, rather than oceanic, char- 

 acter of the era is well shown. The class of Worms included a 

 very small species, having a spiral 

 shell (Fig. 661), and therefore 

 called Spirorbis, which lived at- 

 tached to the leaves and stems of 

 the submerged plants ; and, there- 

 fore, since the plants are not ma- 

 rine, in the fresh-water or brackish- 

 water basins of the continent. The 

 shell is closely like that of modern 

 species of the genus Spirorbis. 



The Crustaceans of the era 

 included a few Trilobites. But 

 there were also other kinds of 

 modern aspect. Fig. 662 repre- 

 sents one, closely related to the 

 modern Limulus, or Horse-shoe 

 Crab, a species of which (often a 



Euproopa Danae. 



