238 



PALEOZOIC TIME. 



In the Eastern-border region, at Pembroke, Me., in a granytic retrion, slates and hard 

 sandstones occur, with many fossils; at other places in northern Maine, the rock is 

 limestone. In Cutler and Lubec, Me., there is a fossiliferous limestone, either of this 

 or of the Niagara period. (C. H. Hitchcock.) 



The formation of Maine extends northeastward to Cape Gaspe\ where there are 

 2,000 feet of limestones, the larger part referred to the Lower Helderberg by Logan, 

 with the upper beds probably Oriskany. 



In southern New Brunswick, rocks of this period occur as a continuation of those of 

 Maine; also in northern New Brunswick; also in the Arisaig district, northern Nova 

 Scotia, shales and limestone, which stretch around to East River of Pictou; also in the 

 Cobequid Mountains, Nova Scotia. 



Figs. 457, 458. 



"km 



II. Life. 



The rocks abound in fossils, beyond even the Niagara or Trenton : 

 over 300 species have been named and described. Among them, there 

 are the same families and genera as in the preceding periods, but with 

 some marks of progress in new forms, and with 

 a range of species almost completely distinct. 

 Yet it has been noted, as a striking fact, that 

 very many of the species of the Niagara period 

 have their closely-related or representative spe- 

 cies in the Lower Helderberg. 



1. Plants. 



Limestone strata seldom contain remains of 

 plants ; and, accordingly, little is known of the 

 Botany of the Lower Helderberg period. 



2. Animals. 



Many Corals and Crinoids occur in the beds ; 



and some of the latter are of remarkable size 



and beauty, — as Mariacrinus nobilissimus H., 



and other species of the same genus. The last 



known remains of the Halysites, or Chain-coral, 



occur in this formation. There were also a few 



species of Cystids (Figs. 457, 458). 



Among Mollusks, Brachiopods are far the most numerous, leading 



in numbers all other kinds of life. Figs. 459-470 represent some of 



the common kinds. 



In the Water -lime, there occur vast numbers of a little, slender, 

 straight shell, called Tentaculites, which have been supposed to be the 

 shells of a kind of worm, of the Serpula family. Fig. 471 represents 

 them, natural size ; and 472, enlarged. 



Trilobites were common still, and one of the species is the Dalmanites 



■Ctstideans. — Fig. 457, Apio 

 cystis Gebhardi ; 458, Aih> 

 malocystites cornutus. 



