MUSEUM OF COMPARATIVE ZOOLOGY. 21 



REPORT ON THE GEOLOGICAL COLLECTIONS. 



By R. W. Sayles. 



During the past year the collections have been added to mainly 

 by purchases. Most of the specimens purchased were sedimentary 

 rocks, illustrating phases of sedimentation. Several very fine 

 examples of opalized wood were acquired. A striking specimen, 

 illustrating concentric jointing, was given by Professor Raymond. 

 Mr. Hugh Nawn gave three very good specimens of fossil tree 

 trunks from the famous Devonian fossil forest discovered by James 

 Hall, at Gilboa, in the upper Schoharie valley in 1870. 



In September, a trip was made to Quebec. In the company of 

 Mr. T. H. Clark, the Beekmantown conglomerates at Levis were 

 examined and studied. A bed of tillite of the sublacustrine type 

 was found by the writer in the cliff at Levis. The enormous 

 boulders of limestone, the shapes of the included rock fragments, 

 and the structure of the matrices of these conglomerates, would 

 seem to preclude anything but ice action in their origin. 



In July, the writer, in company with Mr. Arthur Keith of the 

 U. S. Geological Survey, Prof. Charles Schuchert of Yale Uni- 

 versity, and Prof. A. C. Swinnerton of Antioch College, spent two 

 weeks studying the rocks of Vermont. The Cambrian and Ordo- 

 vician formations near St. Albans were investigated. The Swan- 

 ton comglomerate of Trenton age was studied. One boulder 

 measured 170 feet long by 100 feet wide, another 140 feet long 

 and about 70 feet wide, and another 60 feet long, 30 feet wide, and 

 about 25 feet thick. No known agency but glacial ice could 

 move these boulders to their present positions. 



