312 Proceedings. 



The Sophia Cross collection is a series of minerals, many 

 of them in large and perfect crystals. The specimens were 

 partly collected and partly secured in exchange by Rev. R. T. 

 Cross, chiefly during a residence of some years in Colorado. The 

 collector and his brother, Judson N. Cross, Esq., a resident of 

 Minneapolis, have contributed largely towards securing this 

 choice collection for the Academy. The brothers Cross name it 

 the Sophia Cross collection in memory of their mother. . 



June 9, 1 891. 



Twelve persons present. 



A. W. Stacy and Dr. Adele S. Hutchison were elected mem- 

 bers. 



Secretary C. W. Hall read a paper entitled ''Physiographic 

 and geologic notes of several excursions into northeastern Min- 

 nesota." These notes embody the results of several seasons' work 

 in that portion of the state. 



The following presentations were made : 



An additional mummy case by Thomas Lowry, Esq. 



A boot carrying a colony of oysters, by Charles W. Jerome. 



The secretary was directed to extend the thanks of the Acad- 

 emy to the above named donors for their valuable gifts. 



October 6, I89I. 



Seventeen persons present. 



Albert Schneider was elected a member. 



The following papers were read : 



The Lower Silurian formations of Wisconsin and Minnesota 

 compared, by Fred W. Sardeson. 



Preliminary notes on the conglomerates and amygdaloids of 

 the Snake river valley, by Herbert W. Smith. 



[abstract.] 



Mr. Smith remarked : Beginning at the lower terminus of the enlarge- 

 ment of Snake river, known as Chengwatona lake, and observable at fre- 

 quent intervals from thence, to, or posisbly beyond the Wisconsin line, 

 where this river joins the St. Croix in the eastern part of Pine county, 

 Minnesota, occur several prolonged exposures, in situ, of rocks mentioned 

 in the title to this paper. 



The conglomeratic formations are well displayed along the bed of 

 snake river, particularly in low water; and an exposure say twenty rods 

 wide, gives the appearance of having been cut through by the erosive ac- 

 tion of this stream. This maj^ be located as near Section 24, Township 38, 



