h -- _ H \^rr_ 



VI 



PREFACE. 



an appointment as scientific aid in the United States Department of 

 Agriculture, was engaged at P>erlin in a revision of the Leguminosae 

 of Torto Rico. Ttie revision was based upon a study of collections 

 and literature, unaccompanied by field work in the island. It was 

 originally intended to publish the results of this work conjointly with 

 an account of the agricultural relations of the leguminous plants of 

 that island, but as it proved to be necessary to postpone the prepara- 

 tion of this latter paper foi' more detailed investigation ^Nliss Perkins's 



CI 



paper is now pi^esentcd separately for publication. This paper differ; 

 in several respects from the systematic treatment of legumiuous 

 plants presented in other numbers of these Contributions, and such 

 diti'erences must be taken only as an expression of the views of the 

 author* 



Tlie fifth paper is a '^ Report on the Diatoms of the Albatross V^oy- 

 ages in the Pacific Ocean, 1888-1904," by Dr, Albert JVlamj, assisted in 

 the bibliography and citations by P, L, Ricker. In the autunui of 

 1887 the steamer Albatross, of the United States IJureau of Fisheries, 



which had previously been employed on the Atlantic coast of North 

 America, was dispatched to the Pacific Ocean, where it lias since been 

 engaged in fishery and deep-sea investigations on the western coast of 

 the United States, off* British Columbia and Alaska, and also in more 

 distant regions. The bottom samples obtained by the dredge and 

 sounding cup during the several cruises from 18SS to li)01, inclusive, 

 were referred to Doctor Mann, an expert student of the diatoms, lie 

 has separated and reported on tiiese mimitc plant organisms^ a difficult 

 and painstakitig task, the results of which \ivo given in the papei' pre- 

 sented herewith. With voiy few exceptions the titles in the bibli- 

 ograpliy and the citations throughout the body of the report have been 

 verified b}^ Mr. P. L. Richer, to whom acknowledgment is here made. 



The sixth paper is entitled ^^The Cypcraceae of Costa Rica," by 



■ 



C. H. Clarke. Several years ago Prof. Henri Pittier, while activxly 

 engagtul in studying the plants of Costa Rica, invited Mr. C. R. Clai'ke, 

 of tiie Kew Herbarium, then the greatest living authorit}^ on the 

 Cyperaceae, to prepare a synijpsis of the genera and species of tliat 

 family found in Costa Rica. This work was gladly undertaken by 

 Mr. Clarke. Soon after the synopsis w^as submitted Professor Pittier 

 left Costa Rica to accept a position in the Dc^partment of Agriculture, 

 in Washington, and after his arrival offered the paper to the United 

 States National Museum for publication, Mr, Clarke having died in 

 the meantime, it seemed desirable to publish it with as little change •^^ 



ft- "^' 



possible. As it w^as prepared in Latin, however, tlie Advisor}^ Com- 

 mittee on Publications recommended that it should be translated into 

 English, and Dr. E. L, Greene was asked to prepare the manuscript. 

 In performing this task Doctor Greene has followed as closel^^ as possi- 

 ble the terms and phrasing of Mr, Clarke's papers written in English. 



