No. 4.] HUNT- — ON CAMBRIAN AND SILURIAN. 423 



the fossils in question, was at that time (1860) well-known to 

 belong, both in Great Britain and in Scandinava, to the primordial 

 fauna, Mr. Barrande does not seem to have thought it neces- 

 sary in his correspondence to refer to the very obvious remark of 

 Mr. Billings. 



Mr. Billings further showed in his paper in March, 1862, that 

 fossils identical with those of the Georfjia slates had been found 

 by him in specimens collected by Mr. Richardson of the Geologi- 

 cal Survey of Canada in the summer of 1861, on the Labrador 

 coast, along the strait of Belisle : where Olenellus (^Paradoxides) 

 Thoinpsoni and 0. Vermontana were found with Conocorijphe 

 (Conoceplialus) in strata which were by Billings referred to the 

 Potsdam gioup. [See for the further history of these fossils the 

 Geology of Canada, pages 866, 955, and Pal. Fossils of Canada, 

 pages 11, 419.] 



The interstratification of the dark-colored fossiliferous shales 

 holding Olenellus with the red sandrock of Vermont, announced 

 by Mr. Billings, was further confirmed by Sir William Logan in 

 his account of the section at Swanton, Vermont [Geology of 

 Canada, 281]. They were there declared to occur about 500 

 feet from the base of a series of 2200 feet of strata, consisting 

 chiefly of red sandy dolomites (the so-called sandrock) contain- 

 ing Conocephalus throughout, while the shaly beds held in ad- 

 dition, the two species of Paradoxides (^Olenellus) and some 

 brachiopods. These beds, like those of Labrador, were referred 

 by Logan and by Billings to the Potsdam group. The conclusions 

 here announced were of great importance for the history of the 

 Taconic controversy. The trilobites of primordial type, from 

 Georgia, Vermont, which by Emmons were placed in the Taconic 

 system, lying unconformably beneath a series of rocks belonging 

 to the lower part of the New York system, were now declared to 

 belong to the red sandrock group, a member of this overlying 

 system. Much has been said of these fossils, as if they furnished 

 in some way a vindication of the views of Emmons, and of the 

 Taconic system ; a conclusion which can only be deduced from a 

 misconception of the facts in the case. Emmons had, previous to 

 1860, on lithological and stratigraphical evidence alone, called the 

 Georgia slates Taconic, and placed them unconformably beneath 

 the red sandrock. If now both he and Billings were right in 

 referring the red sandrock to the Calcifcrous and Potsdam for- 

 mations, and if the stratigraphical determination of Messrs. Perry 



