496 HISTORICAL GEOLOGY. 



tigations in Berkshire, Mass., Vermont, eastern New York, and western Connecticut, aim- 

 ing to prove the continuity of tlie rocks of the belt so as to use the Vermont fossils to prove 

 their age, began in 1871, and were continued at intervals to 1887. The last four seasons 

 were employed in obtaining data for a geological map of a large part of the region. 



Tor papers by Dale, Dwight, Walcott, and the author, and an account of Wing's dis- 

 coveries, see the American Journal for the years mentioned ; and for a brief history of 

 Taconic ideas, vol. xxxvi., 1888. The more important of the species of fossils discovered 

 by Wing and identified by Billings, and their varieties, are mentioned beyond, on page 517. 



The Upper Taconic of Emmons, as shown by the fossils at Reynold's Inn, north- 

 east of Bald Mountain, Washington County, N.Y., is Lower Cambrian; and that of 

 Georgia, Vt., another locality, is the same. 



Quebec groiip in Canada. — The Quebec group of Logan (1861-63), established on 

 rocks occurring near Quebec, at Point Levis, and to the south, included (1868): (1) the 

 Levis beds, which were fossiliferous ; (2) the Lauzon beds, green and purple shales, 

 affording Lingula and Obolella ; and (3) the Sillery sandstone, consisting of sandstones 

 and shales. They were regarded by Logan and Billings as mostly of the age of the Cal- 

 ciferous and Chazy groups. The recent investigations of Selwyn (1877, 1882, and later), 

 and the confirmatory studies of R. W. Ells (1889), have proved that the fossiliferous beds 

 include rocks from the Hudson epoch to the Cambrian ; that the Levis is Calciferous in 

 its lower parts ; that the Sillery is probably all Cambrian. (Selvi^yn, Bep. G. Can. for 

 1880, 1881, 1882 ; Ells, ih. for 1889 ; also Walcott, Am. Jour. Sc, Feb., 1890 ; also on the 

 Graptolites, Lapworth, Trans. B. Soc. Can., 1886.) The Quebec group is for the most 

 part a northern portion of the Taconic series. 



In Newfoundland the Quebec series, consisting of limestones and sandstones, is 

 described by Logan and Murray as occurring on the northwest and west coast of New- 

 foundland, along the Straits of Belle Isle, and to the south. It includes the Calciferous, 

 Cambrian, and other beds overlying the Archaean. The thickness given for the Newfound- 

 land-Quebec group is 4600'. For the original account of the Quebec group, see Logan's 

 Beport on the Geology of Canada, 1863, pages 225 and 844. 



LIFE. 



Of the terrestrial animal life of the Lower Silurian era nothing is yet 

 known from American rocks ; but Insects are already reported from those 

 of Europe. The aquatic animals comprised, besides many new species of 

 the several grand divisions represented in the Cambrian, other kinds show- 

 ing progress; and among these, the earliest of Vertebrates — Fishes, as 

 recently announced by C. D. Walcott ; the first known of Barnacles, a group 

 still common along all seashores, and the first of the Eurypterids, a tribe 

 somewhat resembling Crustaceans, but having their only modern representa- 

 tives in four species of Limulus. 



1. Canadian Period. 



1. Calciferous Epoch. 



In the rocks of the Calciferous epoch fossils are usually few, although 

 the limestones have great thickness. Since such limestones are made mainly 

 out of calcareous animal relics, the absence of fossils means that the tritura- 

 ting waters obliterated them by reducing them to the calcareous mud which 

 became the limestone. At some localities fossils are abundant, and there is 



