Albany, N. Y., January 1, 1895. 

 James Hall, LL. D., State Geologist : 



Sir. — Herewith I beg to communicate for your report a paper 

 which I have entitled " A Handbook of the Genera of the North 

 American Palaeozoic Bryozoa," prefaced by. some observations 

 upon the structure of living species. 



This work is the direct outcome of the investigations made in 

 preparation of Yolume YI of the Palaeontology of New York 

 (1887), and has been done by me as a member of the staff of the 

 geological department. The collections made for use in that 

 work, as well as your own private collection, and, through your 

 intervention, those of the American Museum of Natural History 

 of New York, have been freely accessible to my use, and I take 

 this opportunity of expressing my appreciation of the favorable 

 conditions under which my work has been done. 



Yery respectfully yours, 



GEORGE B. SIMPSON. 



