238 



PALEOZOIC TIME. 





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

 sandstones occur, with man}' fossils; at other places in northern Maine, the rock is 

 limestone. The Littleton, N. H., beds have afforded Favosites basaltica, a Zaphrentis, 

 and Pentamerus Knightii. 



The formation of Maine extends northeastward to Cape Gasp£, where there are 

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

 with the upper beds probably Qriskany. 



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. 



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 

 Fhjs. 457, 458. „ - i , -,. • 



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. 



>. 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 

 Cystideans — Fig. 457, Apio- known remains of the Halysites, or Chain-coral, 

 cystis Gebhardi ; 458, Ano- occur j n t hi s formation. There were also a few 



malocystites cornutus. . „ . 



species of Cystids (Figs. 4o7, 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 



