PREP ACE. XI 



of Dr. G. A. WiLLiAJis, formerly of Hardy county, Virginia, now of Boon- 

 ville, Missouri; and of Dr. James Knapp, of Louisville, Kentucky. Dr. C. 

 RoMiNGER, of Ann Arbor, Michigan, has very liberally given me the use of 

 many specimens illustrating the internal structure of species; and he has 

 placed at my disposal his collection of European and American Brachiopoda 

 for further use in completing an introduction to the study of American 

 Palaeozoic Brachiopoda, which is already advanced, and will appear as a 

 supplement to the present volume. I have been indebted to Mr. S. S. Lyon, 

 of JefTersonville, Indiana, for the means of illustrating the interior of Meeis- 

 TELLA, (S. G. Pentagonia), as well as for other specimens. I have received 

 from Mr. 0. H. St. John, of Waterloo, Iowa, interesting specimens of 

 Brachiopoda, from the Hamilton and Chemung groups of that part of the 

 country. For the illustration of several forms among the Spiriferid^, I 

 have been permitted the use of specimens from the collection of Col. E. 

 Jewett. From Mr. Joseph Sullivant, of Columbus, Ohio, I have received 

 specimens from the Corniferous limestone of that vicinity ; and to the late 

 Dr. Mann, of Milford, Ohio, I have been indebted for many interesting 

 specimens. Tlirough the kindness of Prof. Wright, of Hamilton and Mr. 

 J. De Cew, of Cayuga, Canada West, I have received many specimens of 

 interest from the Corniferous limestone of that region. 



It has been to me a great satisfaction, that through many years, I expe- 

 rienced the uninterrupted liberality and kind interest of the late Ledyard 

 LiNCKLAEN, o( Cazenovia, whose devotion to geological science never ceased ; 

 and it is with a sad heart that I here record this memento of one whose 

 noble manhood was everywhere acknowledged, and whose quiet, but per- 

 sistent advocacy of an advancing science, has produced many good and 

 permanent results, and has exerted an influence not to be forgotten. 



Maech, 1867. 



