11 



scopic sections of the rocks in the collection, and the number of 

 these now available for use by students of lithology now exceeds 

 two thousand. 



The Sturgis-Hooper Professor published in April the second 

 part of the " Climatic Changes of Later Geological Times," and 

 in October the third and final portion of that work. This com- 

 pletes the seventh volume of the Memoirs of the Museum. He 

 also published in the Bulletin of Harvard University a " List of 

 American Authors in Geology and Palaeontology." 



The following papers have been published during the current 

 year in the lithological department: — 



By Dr. Wadsiyortii. 



1. Some Points relating to the Geological Exploration of the Fortieth 

 Parallel. Proc. Bost. Soc. Nat. Hist., 1881, XXI. 243-274. 



2. On the Relation of the Quincy Granite to the Primordial Argil- 

 lite of Braintree, Mass. Ibid., pp. 274-277 ; Harvard Univ. Bull., 1882, 

 II. 360. 



3. On the Trachyte of Marblehead Neck, Mass. Proc. Bost. Soc. 

 Nat. Hist., 1881, XXI. 288-294; Harvard Univ. Bull., 1881, II. 267. 



4. On the Lithological Character of the Palaeolithic Implements of 

 the Valley of the Delaware. Proc. Bost. Soc. Nat. Hist., 1881. XXI. 

 146, 147. 



5. Notes in Geology and Lithology. Including 



(a) The Marblehead Diabase. 



(b) Picotite found in the Groundmass and Feldspar of Basalt. 



(c) Zircon-Syenite from Marblehead, Mass. 

 (e?) The Stoneham Limestone. 



(/) On the Relations of the so-called Felsite to the Conglomer- 

 ate on Central Avenue, Milton, Mass. Harvard I'niv. 

 Bull., 1882, II. 359, 360, etc. ; Proc. Bost. Soc. Nat. 

 Hist., 1881-82, XXI. 306, 314, 315, etc. 



By John Eliot "Wolff, Assistant in Geology in the College, and Can- 

 didate for the Degree of Ph.D. 



6. The Great Dike at Hough'a N<rk. Quincy, Mass. Bull. Mus. 

 Comp. Zool., 1882, VII. 231-242. 



A considerable amount of other material in lithology and 

 geology has been partially prepared for publication, and will 

 probably be completed and placed in the hands of the p 

 (lining the coming year. 



