368 



Dr. C. T. Jackson presented a copy of William Mc- 

 Clure's Geological Map of the United States, which had 

 been reprinted by M. Jules Marcou, as the first geolog- 

 ical map of the United States. It presents the great 

 outlines of American Geology with considerable accu- 

 racy, although the map is necessarily incomplete, as there 

 had been, at the time of its publication, but cursory sur- 

 veys of the country. 



Dr. Jackson presented, also, in behalf of M. Marcou, 

 a Geological Map of New Mexico, embracing his sur- 

 veys between 103° and 109° of longitude, and between 

 30° and 35° of latitude. This map presents the out- 

 lines of the Quaternary, Cretaceous, Jurassic, New Red 

 Sandstone, Carboniferous, Granite, Gneiss, Porphyrons 

 Trap, and Volcanic Series of Rocks. 



Dr. J. remarked that few American geologists had 

 made such extensive explorations of North America as 

 M. Marcou, though, from their very extent, his researches 

 could not be so complete as those of local geologists. 



Prof. Agassiz said that the labors of M. Marcou in 

 this country had been criticized and disparaged, as if he 

 had undertaken a general and complete treatise upon the 

 geology of America ; whereas his investigations were 

 principally directed to a comparison with the equivalent 

 formations of Europe. 



The Curator of Radiata, Mr. Theodore Lyman, pre- 

 sented in the name of Prof. Agassiz, a number of Echin- 

 oderms collected by Prof. A. and Mr. James E. Mills 

 upon Grand Manan Island, N. B. 



Prof. Agassiz, in reply to a question from Mr. James M. Bar- 

 nard, who said that he had heard of Echinoderuis burrowing into 

 hard rock, observed that he had no doubt that they do burrow 

 into limestone, as they are found in holes just the size of the 

 animal. Such a process might be effected by their vibratory 

 cilias. 



