48 
55. Examination of Shells obtained by the Sounding-Lead 
in the Coast Survey of New York and New Jersey, 
with some Nautical Hints, by Augustus A. Gould. 
56. On the probable immediate Cause of the Glacial Epoch 
of the Post-Tertiary, by A. Guyot. 
57. On the Lower Silurian Oils of Kentucky and Ten 
nessee, by J. S. Newberry. 
58. Suggestions relative to the Annular Eclipse of the Sun, 
of October next, by S. Alexander. 
59. On Certain Converging Series expressing the Ratio 
of the Diameter to the Circumference of the Circle, 
by William Ferrel. (Communicated by Benjamin 
Peirce.) 
60. On a Tide Meter, by J. M. Batchelder. (Communi- 
eated by Benjamin Peirce.) 
61. On the Silver Reduction Process of Nevada, with Sta- 
tistical Tables, and Metallurgical Data, by B. Silliman. 
62. On a New General Method of Volumetric Analysis, by 
Wolcott Gibbs. 
63. On Sodium Amalgam, and its Application in Saving 
Precious Metals, by B. Silliman. 
64. On the Limits and Character of the Vision of American 
Soldiers, as deduced by the Statistical Department of 
the U. S. Sanitary Commission, by B. A. Gould. 
65. On the Primary Triangulation of the Coast of New 
England, in connection with the U. S. Coast Survey, 
by A. D. Bache. 
66. On the Relation of Language to Ethnology, by W- D- 
Whitney. 
67. On Certain Mineral Districts of Arizona, by B. Silli- 
man. 
c fe 68. On California Petroleum, and the Products of its Dis- 
* 
tillation, by B. Silliman. 
