xiv PREFACE. 



have profited by the collections of fossils made from 1856 to 1865 inclusive, 

 when appropriations for such collections ceased. 



This final volume (VIII, Part II), after being held back for one year through 

 want of an appropriation, was printed to page 317 in the autumn of 1893. 

 At that point the printing was again suspended. In order to have a record of 

 the date of the completed work, there was issued, in July, 1893, a fascicle 

 containing the text, from page 1-176 ; embracing descriptions of the spire- 

 bearing genera ; and a second fascicle in December, 1893, carrying the text to 

 page 317, including descriptions of the rhynchonelloids, pentameroids and 

 terebratuloids. At that time the concluding chapter or summary was in type, 

 but the appropriation having been exhausted the printer was compelled to sus- 

 pend all work upon the volume ; so that this chapter, bringing the text up to 

 350 pages, together with accompanying and concluding matter, was laid over 

 to the present year. 



In the original scheme of the work on the BaACHioPODA the generic descrip- 

 tions were to be accompanied with illustrations of the microscopic structure of 

 the shell, but it was found inconvenient to accomplish this plan during its 

 progress ; though a large number of sections were prepared for microscopic 

 study. This part of the work is postponed for the present, and probably will 

 not be taken up again by the writer. 



The great length of time since these studies were resumed in 1888, has 

 enabled those assistants who were with me in the earlier preparation of the 

 work to advance their investigations in the same line of concept, and to anti- 

 cipate some of the results which have been reached in these volumes. While 

 the final result in this direction is still distant, it is encouraging to see the work 

 advancing in what the writer believes to be the only true method of studying 

 every class of organisms. 



In the Preface to Part I of Volume VIII, the author made acknowledgments 

 to many personal friends, to collectors of fossils, to museums and geological 

 surveys ; he wishes to repeat these acknowledgments in the Preface to Part II, 

 since this will probably be his last opportunity of connecting their names with 

 the progress of the " Palaeontology of New York." 



