150 KEPORT ON NATIONAL MUSEUM. 



considerable quantity of dux)licate specimens was set aside for exchange. Subse- 

 quent investigation has shown the desirability of retaining a large part of these in 

 the Museum, and it is therefore necessary to review them again before any are sent 

 out. 



Since even an extensive collection of fossil invertebrates may bo presumed to be less 

 attractive to the public than much of the material of other departments, my plans 

 have contemplated mainly such a classification and arrangement of the Museum col- 

 lection as will make it conveniently available to students for scientific piirposes. 

 The fact that so large a part of these specimens are those upon which official reports 

 and other scientific writings have been based, makes it especially desirable that they 

 shall be made accessible to students of paleontology as early as practicable. 



DEPARTMENT OP POSSIL PLANTS. 



This department, like that of fossil invertebrates, is under the honor- 

 ary curatorship of an officer of the United States Geological Survey, 

 Prof. Lester F. Ward. The collection is installed in the drawers of a 

 number of unit-table cases in the west south range and upon the south 

 balcony, contiguous to which at its east end is the laboratory of the 

 curator. This laboratory has during the year been filled up with cases, 

 and a large amount of preliminary work has been done by the curator, 

 who since October has been assisted by Mr. E. E. Hayden, midshipman 

 of the United States Navy. This collection, like many others, has been 

 in a quiescent state for many years, and a large amount of work has 

 been found necessary, preliminary to its final arrangement in proper 

 shape for study. No effort has as yet been made to provide exhibition 

 space for it. Its present condition is well shown by the followiug ex- 

 extracts from Professor Ward's report: 



The extensive collection which had been received from Mr. Leo Lesquereux, of Co- 

 lumbus, Ohio, who had jjreviously employed it in the preparation of his printed re- 

 ports, and had catalogued and numbered it; according to your instructious, was merely 

 luipacked during the last months of 1881, and remained at the beginning of the year 

 in a wholly unorganized condition. The bulk of the work done in the department 

 has therefore been that of systematically classifying and arranging this material. This 

 work was delayed by the necessity of having appropriate cases erected in the labora- 

 tory rooms to receive it, as also by the lack of assistance and the performance of du- 

 ties in connection with the Geological Survey. 



The deficiencies of a ftierely chronological catalogue rendered necessary the prepa- 

 ration of a much more complete and convenient slip catalogue, which could be sys- 

 tematically arranged and serve as an efficient aid iu the progress of the work. 



The catalogued material has been arranged in three series according to horizon, 

 viz, the Cretaceous (chiefly from the Dakota Group), the Tertiary (including for con- 

 venience the Laramie Group, which Mr. Lesquereux considers to be Eocene), and the 

 Carboniferous and lower formations (there being a few fi-om the Old Red Sandstone 

 of Ireland, and a few from the Silurian of New York). 



The system of classification adopted is, in so far as this was practicable, that of 

 Schimper, as given in his "Traitd de Pal^ontologie V^gdtale," the most comprehen- 

 sive work on the subject. 



As the greater part of the undetermined material in the department belongs to the 

 later formations, and as my field work for a great while will probably be chiefly con- 

 fined to these horizons, I have found it necessary to reserve, for the present at least, 

 the whole of the Cretaceous and Tertiary collection and retain it in the laboratory 

 as a basis for comparison and investigation. For the same reason I have not thought 



