OF AETS AND SCIENCES. 203 



will soon take up the subject. He should examine Snake Mountain, 

 Sharp Shins, the Red Sandrock at Ilighgate, and the cliff along the 

 shore from Phillipsburgh to the mouth of Rock River on Missisquoi 

 Bay. 



" I could publish a great deal myself, but cannot well do so. You 

 are an old officer, and know well what subordination means. I fear I 

 have made this badly written letter too long. 



" Yours very sincerely, 



" E. Billings." 



The principal results of my first exploration, in September and Octo- 

 ber, 1861, were, 1st, a complete confirmatiun of the laconic system; 

 2d, the absence of metamorphic rocks in the upper Taconic from 

 Snake Mountain and Georgia, Vermont, to Point Levis ; 3d, the 

 creation and exact position of the divisions of the " Georgia slates " 

 and "St. Albans group" at the base of the upper Taconic; 4th, the 

 maintaining the Potsdam sandstone in the upper Taconic and the Pri- 

 mordial fauna which it covers, as I had proposed in the first notice 

 published jointly with M. Barrande. 



These views were presented to the Boston Society of Natural His- 

 tory at the meeting held November 6, 1861, and a notice, entitled, 

 "The Taconic and Lower Silurian Rocks of Vermont and Canada," 

 was published in the Proceedings, vol. viii. p. 239, November, 1861, 

 which sums up the fixcts obtained. 



Mr. Barrande wrote me the following letter in regard to my re- 

 searches at Point Levis and Georgia. 



" Prague, 9 Nov., 1861, 

 Kleinseite, No. 419 Choteksgasse. 



** Mox CHER Monsieur Marcou : — 



" J'apprends avec beaucoup de plaisir par votre lettre du 2 Octobre, 

 que vous avez fait votre voyage d'exploration dans le Vermont et dans 

 le Canada, avec succes et satisfaction. Je suis a votre disposition pour 

 presenter a la Societe Geologiqne de France le memoire que vous vous 

 proposez de rediger cet hiver, sur vos observations. 



" Si vous etablissez nettement la succession des formations de la 

 Pointe Levis, ce sera un point fort important. La succession des 

 formations observee a Belle Isle, par Mr, Ricliardson vient fort h pro- 

 pos pour confirraer toutes nos vues. C'est magnifique, suivant votre 

 expression, et la lumiere se fait de plus en plus, avec une rapidite que 



