CARBONIFEROUS PERIOD. 



347 



fragments of many other specimens of the Pupa, and a few indi- 

 viduals of a small Spirorbis, the spiral shell of a worm of the Serpula 

 tribe. The figure on p. 326 (fig. 560) represents a section of the 

 part of the Coal measures in which these remains were found : the 

 stump was twenty-two inches in diameter and nine feet high. The 

 first discoveries at this place were made by Dawson and Lyell, in 

 1851. Dawson observes that the shells were probably the food of 

 the Eeptiles, adding that he has found in the stomach of a recent 

 Menobranchus (M. lateralis) as many as eleven unbroken shells of the 

 fresh-water snail Physa heterostropha. 



Such a congregation of animals in a single stump proves, as Daw- 

 son states, that the species of the tribes represented were not rare 

 in the marshes and forests of Carboniferous Acadia. 



A terrestrial feature thus appears in three out of the four sub-king- 

 doms, — the Molluscan, Articulate, and Vertebrate. There are land 

 and fresh-water shells in the first ; Insects and Myriapods (or Centi- 

 pedes) in the second ; Amphibians and other Eeptiles in the third. 

 The Eadiate sub-kingdom contains no terrestrial species, and hence 

 did not admit of the same kind of progress. 



Characteristic Species. 



1. Protozoans. — Ehizopods. — Fusulina cylindrica and F. elongata, resem- 

 bling fig. 193, p. 164. The first is a Russian species, and there is some question 

 whether the American is identical with it. It occurs in vast numbers, almost 

 making up the limestones in some places, and has been observed in Ohio, Illi- 

 nois, Missouri, and Kansas. In the United States the genus Fusulina is confined 

 to the Coal measures ; but in Russia it occurs also in the Subcarboniferous rocks. 



2. Radiates. — (a.) Polyps. — The Coral Cyathaxonia prolifera McChesney, 

 from Illinois. (6.) Echinoderms. — Crinoids of the genera Poteriocrinus, Actino- 

 crinus, etc. ; Echinoids of the Palaaozoic genus Archseocidaris. 



3. Mollusks. — (a.) Bvachiopods. — Fig. 591, Spirifer cameratus Morton (S. 

 Meusebachanus Roemer), from the Lower and Upper Coal measures, and occur- 

 ring in Ohio, Kentucky, Illinois, Missouri, Kansas, Texas, New Mexico, and 

 Utah. This species is closely allied to S. striatus (figs. 211, 212, p. 181), and is 



the fore-feet, support was afforded to a membrane which extended to the tail 

 and made a wing for flying. The remaining fingers were short and furnished 

 with claws. The long, slender jaws were set with a large number of teeth in a 

 groove. The bones were hollow and light, as in birds. They had the habits of 

 bats, and wings of a similar character. But in bats, all the fingers of the hand 

 but the thumb are elongated for the purpose of the wing, and the thumb alone 

 is used for clinging. 



Chelonians.— The Turtles, or Chelonians, are of two tribes: — 



1. The Sea- Turtles, — furnished with paddles instead of feet. 



2. The Land- Turtles, — furnished with feet. 



