observations were made at a place called Corbitt's Mills, 

 where the well known auriferous Silurian slates are 

 immediately overlaid, unconformably, by conglomerates, 

 grits and sandstones of Lower Carboniferous age. The 

 lower portion of the conglomerates and grits also con- 

 tain an abundance of gold, which was undoubtedly 

 extracted from the underlying slates, while the former 

 deposits were in process of formation, and was mixed 

 with the loose gravel material which afterwards became 

 consolidated. 



We owe to Hartt the careful investigation of the rela- 

 tions of the different members of the Carboniferous lime- 

 stone deposits, in the neighborhood of Windsor, Stewi- 

 acke, etc., Nova Scotia. He collected and studied the 

 faunae of each separate set of beds with much pains, and 

 in this way was enabled to determine their sequence. 

 The fossils, which are marine, are very numerous, and 

 some new species were described by him in the "Acadian 

 Geology." Much interest attaches to the study of this 

 formation at the above localities, where, in the upper 

 beds, occur many forms common to both the Carbon- 

 iferous and the Permian, and a great likeness is apparent 

 to the upper members of the Carboniferous system in the 

 western United States, called Permo-Carboniferous. Dr. 

 Meek, who exanlined the fossils, suggested that we 

 might have here " what Barrande would call an upper 

 Coal-measure, or even Permo-Carboniferous fauna, 'col- 

 onized ' far back in the Sub-Carboniferous period." Dr. 

 Dawson has greatly enlarged on Hartt's results, and 

 shows that the divisions made by him are of a more gen- 

 eral character than he had supposed. 



In many places in his "Acadian Geology," Dr. Dawson 

 refers to the work of Prof. Hartt in various parts of 

 Nova Scotia and New Brunswick, and it is known that, 

 at the. time of his death, he had still remaining some 

 original material from the Provinces which he never had 

 the time to study or publish. 



Upon the organization of the Thayer Expedition to 

 Brazil, by Prof. Agassiz, Mr. Hartt was appointed one 



