52 REPORT OF NATIONAL MUSEUM, 1897. 



Special investigations have been prosecuted by members of tbe staff 

 of this department, as follows: 



Mr. Benedict, assistant curator, has made a study of the Isopoda, 

 especially those collected by the steamer Albatross. He has deter- 

 mined the bulli of the unnamed specimens, and has nearly completed a 

 report upon the same, for which a number of drawings have been made. 



Miss Rathbun, second assistant curator, has continued her studies of 

 the Brachyura, and has completed a revision of the nomenclature. 

 Special studies of the PalicidoB, the fresh-water crabs, and the genera 

 Callinectes, iSesarma, and Etliusa., have also been carried on. 



Miss Rathbun was on detached service for four months for the pur- 

 pose of visiting the museums of London, Copenhagen, Kiel, Berlin, 

 Geneva, and Paris. During her travels many type specimens of deca- 

 pod Crustacea were examined, and about 140 photographs made for 

 future comparison and study. Exchanges were arranged with the 

 museums visited, and one series has already been received from each. 

 The number of species represented in these collections is ITO, and the 

 number of spe(!imens, 312. Nearly all the species are new to the collec- 

 tion, and 28 type specimens are included. 



Some of the museums visited kindly lent specimens of crabs to the 

 U. S. National Museum for study. 



Those who Avere especially instrumental in bringing about these 

 results were Sir William H. Flower, Mr. Charles E. Fagan, and Prof. F. 

 Jeffrey Bell, of the British Museum of Natural History; Dr. F. Meinert, 

 of the Zoological Museum, Copenhagen; Dr. K. Brandt, director of the 

 Zoological Institute, Kiel, Germany; Dr. K. Mobius, director of the 

 Eoyal Zoological Museum, Berlin; Dr. F. Hilgendorf, also of the Berlin 

 Museum; Dr. N. d'Adelung and Prof. H. de Saussure, of the Museum 

 of Natural History, Geneva, Switzerland; and Prof. A. Milne-Edwards 

 and Prof. E. L. Bouvier, of the Museum of Natural History, Paris. 



Material for study and examination has been sent to five specialists 

 during the year, and others have prosecuted investigations in the 

 department. Further reference to these matters will be found in 

 another part of this Report. 



Assistance has been rendered in various ways by persons not con- 

 nected with the Museum, as may be seen from the following paragraphs 

 taken from the report of the honorary curator : 



Dr. Walter Faxon submitted for publication a report on the crayfishes added to 

 our collection during recent years, at the same time returning the specimens upon 

 which the report is based, and adding others from the collections of the Museum of 

 Comparative Zoology at Cambridge. 



Prof. C. C. Nutting, who is monographing the hydroids, including the large col- 

 lection belonging to the Museum, has completed and transmitted for publication 

 that part treating of the Plnmu]arid;e. 



Dr. A. Zumbrach was a volunteer assistant in the department from October to 

 June, rendering valuable service during that time in translating from the German. 



Mr. W. P. Hay, professor of zoology at the Central High School, who has assisted 

 the department in various ways, contributed his entire collection of crayfishes, 

 including manj' types. 



