LETTER OF TRANSMITTAL. 



Washington, June 15, 1883. 

 Sir: I herewith transmit to you the manuscript of a Eeview of the 

 Fossil Ostreidte of North America, which, at your request, I have pre- 

 pared for your Aunual Keport for 1883. The work is necessarily, to a 

 large extent, a compilation of material that has already been published, 

 but I have attempted to group that material in such a manner as to 

 convey to the general reader an outline of the geological history of the 

 oyster family, and the "connection of the extinct with the living forms 



of oysters. 



Two important parts of this work have been prepared by Mr. John A. 

 Eyder and Prof. Angelo Heilprin, respectively. Mr. Kyder has prepared 

 a concise life-history of the common living oyster of the Atlantic coast, 

 which he has illustrated by original drawings of his own, and from ma- 

 terial which he has prepared in connection with the United States Fish 

 Commission. 



Professor Heilprin has kindly furnished all that portion of the text 

 which relates to the Tertiary and post- Pliocene oysters, which material 

 is, in great part, the result of his special studies of the Tertiary raol- 

 lusca of the United States. 



All this work is, in accordance with your request, addressed to the 

 general reader, rather than to the special student ; but in doing this we 

 have striven to avoid all scientific inaccuracy of statement. Like my 

 contribution to your report for last year, this is a general review of the 

 subject of which it treats, and not a revision or rectification of the forms 

 which are enumerated and illustrated. Such a rectification is needed, 

 but it must necessarily be deferred until another time. 



The drawings, with the exception of the few that have previously 

 been published, are from the pen of Dr. J. C. McConnell, who also 

 drew the numerous illustrations for my contribution to your report for 



last year. 



Besides the aid received from Messrs. Eyder and Heilprin, whose work 

 appears under their respective names, I am also indebted to Mr. W. H. 

 Ball, of the Coast Survey, and Lieut. Francis Winslow, United States 

 Navy, for much information concerning the variation and distribution 



of the living oysters of our coasts. 



279 



