@XXVlll THE PALEONTOLOGY OF MINNESOTA. 
Dates of publication. 
Some of the chapters in Part Il were published in advance, at the following dates, in 
a small edition of 100 copies, viz.: 
The Lower Silurian Lamellibranchiata, June 16, 1894. 
The Lower Silurian Ostracoda, July 24, 1894. 
The Lower Silurian Trilobites, September 27, 1894. 
The other chapters in Part II have the date of publication of the volume, though still 
circulated separately in the same manner, February 15, 1897. 
ACKNOWLEDGMENTS. 
The authors of the chapters in Part II desire to thank the following persons for assist- 
ance: Dr. C. E. Beecher, for the use of specimens belonging to the Peabody Museum, 
Yale University; Dr. C. H. Robbins, of Wykoff, and Mr. R. H. Hasse, of Granger, Minn.; 
Prof. Alpheus Hyatt, Boston, Mass.; Mr. J. F. Whiteaves, Ottawa, Canada, for the oppor 
tunity to examine type specimens belonging to the Geological Survey of Canada; Prof. J. 
M. Safford, Nashville, Tenn., for the use of many specimens from Tennessee, and Prof. R. 
P. Whitfield, of the American Museum of Natural History, New York, for similar favors. 
ERRATA. 
FOR PART II, PAGES 475 TO 1081. 
P. 490. Fourteenth line from top, after which insert ite 
P. 504. Fifteenth line from bottom, add M. modioliformis M. and W. 
P. 536. Eighth line from bottom, for “SUBOVATA, ”. Sp.” read HURONENSIS Billings. (A 
recent comparison of our specimens with the original types of Billings’ species has shown that they belong 
to the same species.) 
P. 537. Omit the paragraph which occupies the eighteenth to the twenty-second lines from the top. 
P. 581. Eighth line from bottom, add 7ecurva Ulrich, similis Ulrich and ? hamburgensis 
Walcott. 
P. 632. Ninth line from top, before Tetradelia insert Ceratopsis Ulrich. 
P. 657. Ninth line from bottom. for “ Ceratella”’ reaa Ceratopsis. 
P. 659, Fifth line from top, tor “ Ceratella chambersi” reaa Ceratopsis chambersi. 
Explanation of plate XX XIX, thirteenth line from the top, for ‘‘ CTENODONTA GIBBERA” read 
CYRTODONTA GIBBERA 
Explanation of plate XX XIX, thirtieth line from the bottom, for “‘“CyRTODONTA SUBOVATA, 7. Sp.,”’ 
read CYRTODONTA HURONENSIS Billings. 
ADDITIONAL ERRATA are to be found as follows: for the chapter on Lamellibranchiata on page 
928; or the chapter on Cephalopoda on page 812; for the chapter on Gastropoda On page 1081. 
