Hartt.] 152 [March 20, 
exist in the United States, especially in Missouri and Cali- 
fornia, and that furnaces are actually being made for tin 
smelting in the former State. The President asked for in- 
formation from any member on this point. 
Dr. Kneeland replied that specimens of the Missouri ore 
recently sent to the Institute of Technology for analysis, 
proved to contain no tin. 
Dr. Brewer exhibited a beautiful Trogon, Pharomacrus 
mocinno, presented by Mr. Juan Zelidon, a gentleman en- 
gaged in collecting the birds of Costa Rica. 
Dr. Brewer also stated that the Smithsonian Institute had 
- presented a valuable collection of woodpeckers to the Society, 
many of them new to the collection, which already contains 
about three-fourths of the known species of this large family. 
The thanks of the Society were voted for both gifts. 
Section of Microscopy. March 138, 1872. 
Prof. W. H. Niles in the chair. Thirteen persons present. 
Mr. Stodder gave a short account of the recent discussion 
as to the structure of the Podura scale, exhibiting drawings 
and specimens. 
Mr. R. 8. Chase of Haverhill, was elected a member of the 
Section. 
March 20, 1872. 
The President in the chair. Thirty-one persons present. 
At the invitation of the chair, Prof. Ch. Fred. Hartt gave 
an account of his recent explorations of the eastern part of — 
the Basin of the Amazonas, and of their results, bearing more 
