No. 3.] BILLINGS — ON THE tTACONIC CONTROVERSY. 319 



Calciferous and Chazy. On the 12th July I wrote to Barrande 

 on the subject, and informed him that I considered the fossils of 

 the age of those of the base of his second fauna. In August I 

 published figures and short descriptions of the principal species. 

 In this paper the designation '' Hudson River group " was first 

 discontinued as the name of the formation, and I am happy to 

 state that it has never since been applied to the rocks in question, 

 in any of the publications of our Survey. I had a number of 

 separate copies of my paper printed, and sent one with a letter to 

 each of the following palaeontologists and geologists : — M. J. 

 Barrande, Paris ; J. W. Salter, Geo. Sur. G. B., London ; Dr. 

 B. F. Shumard, St. Louis, Missouri; and Prof. J. M. Safi"ord, 

 Lebanon, Tennessee. All of them agreed with me without any 

 reservation whatever. 



Previously to the discovery of these fossils. Prof. Hall had 

 examined the rocks at Point Levis, and had described a number 

 of species of graptolites that had been collected there. In his 

 report he says, " These strata belong to the Lower Silurian 

 series, and are of that part of the Hudson River group which is 

 sometimes designated as Eaton's sparry limestone, being near the 

 summit of the group : they form also the rocks of Quebec." 



Dr. Hunt in commenting upon the investigations of Prof. Hall 

 and myself says : — 



" The palseontological evidence thus obtained by Billings atid 

 by Hall, both from near Quebec and in Vermont, led to the con- 

 clusion that the strata of these regions, so much resembling the 

 upper members of the Champlain division, were really a great 

 developement, in a modified form, of some of its lower portions." 



Now I object to this mode of stating the matter. It seems 

 to associate Prof. Hall with me in the determination of the age 

 of the rocks in question. Taking this passage, with others that 

 precede it, the reader might suppose that Prof. Hall and I had 

 studied the fossils together, and had arrived at the same conclu- 

 sion. On the contrary we examined them separately and came 

 to widely different conclusions. He placed them, incorrectly, at 

 the summit of the Champlain group, and I, correctly, at the base. 



During the years 1859 and 1860, Sir W. E. Logan made 

 numerous excursions into the disputed territory, and examined a 

 great number of localities, in order to find a clue to the true 

 stratigraphical arrangement, I believe no other physical geolo- 



