REPORT OF ASSISTANT SECRETARY. 21 



DEPARTMENT OF INVERTEBRATE FOSSILS (Paleozoic). 



This department is under the charge of Mr. C. D. Walcott, of the U. 

 S. Geological Survey. The collection now includes over 80,000 speci- 

 mens, of which perhaps one-third has been transferred by the U. S. 

 Geological Survey to the Museum. During his connection with the 

 Museum Mr. Walcott has thoroughly arranged this material. A very 

 interesting series has been selected for exhibition, although up to the 

 present time it has been impracticable to place any material upon view. 



The curator has been engaged in a special research, in behalf of the 

 U. S. Geological Survey, upon the stratigraphy and paleontology of 

 the Cambrian system of North America. 



Prior to the year 1884 the increase iu the material of this depart- 

 ment had been irregular, owing to the lack of time and means at the dis- 

 posal of the curator; during that year, however, Mr. Walcott intro- 

 duced a thorough system of classification, and began the formation of a 

 systematic collection of Cambrian fossils. 



DEPARTxWENT OF INVERTEBRATE FOSSILS (MeSOZOic). 



The principal accessions to the collection have been those received 

 from the U. S. Geological Survey. The curator, Dr. C. A. White, re- 

 ports that a total number of 1,563 entries were made iu the catalogue 

 during the year. Among the accessions of special interest was a col- 

 lection of Cretaceous fossils from Mexico, and another of Lower Creta- 

 ceous and Jurassic from France. The total number of specimens in the 

 collection at present is 69,742. 



Steady progress has been made in the work of arrangement and 

 classification ; and the collection is now accessible for rmrposes of study. 

 The provisional arrangement which has been adopted, is purely strati- 

 graphical ; though a broad biological classification under each geological 

 period has been attempted. Mr. J. B. Marcou has -re-identified all the 

 type specimens, and has published a catalogue of these in the Proceed- 

 ings of the Museum.* 



DEPARTMENT OF INVERTEBRATE FOSSILS (CeilOZOic.) 



Since the transfer of Mr. W. H. Dal I from the Coast Survey to the 

 U. S. Geological Survey, in which he is now serving as palaeontologist 

 in charge of the later formations, this department has been organized. 

 It is, however, really inseparable from the department of mollusks, of 

 which Mr. Dall has long been curator. 



DIVISION OF BOTANY. 



DEPARTMENT OF FOSSIL AND RECENT PLANTS. 



The attention of the curator of these two departments, Prof. Lester 

 F. Ward, of the Geological Survey, has been directed chiefly toward 

 the study of the fossil plants : his sketch of the history and present 



* Proc. U. S. Nat. Mus., vm, 18=5, pp. 290-3447" 



