Jan., 1914. Annual Report of the Director. 305 



history and their structure. Diatoms were formerly appreciated 

 mainly because of their aesthetic beauty as microscope objects, 

 but recently they are coming into prominence on account of their 

 recognition as one of the fundamental food supplies of marine 

 life. The series exhibited comprises: 



•The Barrel Diatom {Melosira Borreri) in colony and individual growth. 



The Triangle Diatom ( Triceratium favus) in single and dissected speci- 

 mens, the latter illustrating the structural parts of diatoms. 



The Bristled Diatom (Chcctoceras Lorenzianum) in chain formation. 



The Fan Diatom (Licmorpha flabellata) two colonies attached to an alga. 



The Sun Diatom {Planctionetta Sol), highly magnified. 



The Bristling Rod Diatom (Bacteriastrum varians), in chain colony 

 growth. 



Two Stylus Diatoms {Rhizosolenia styliformis and setigera), in chain 

 growth and separate individuals. 



All these forms are reproduced very highly magnified to show their 

 distinctive characters. 



The meteorite collection has been entirely reinstalled in order to 

 incorporate into it the specimens, numbering about 1,600, of the Ward- 

 Coonley collection. As exhibition space was not available for the entire 

 collection it was divided, the iron meteorites being installed in Alcove 

 106 and the stone and iron-stone meteorites in Hall 63, which is not at 

 present open to the public. In making this reinstallation, all specimens 

 have been placed according to the falls to which they belong so as to 

 make the representation of the different falls as complete as possible. 

 The installation in Alcove 106 is in the cases previously used for the 

 collection, and that in Hall 63, in the cases obtained with the Ward- 

 Coonley collection. All casts have been withdrawn from exhibition 

 partly for lack of space and partly because their presence is liable to 

 cause confusion. The installation of the meteorite collection is now 

 complete with the exception of the Canyon Diablo specimens, the bases 

 for which have not yet been prepared. It is intended that the Canyon 

 Diablo specimens, when installed, will occupy a single case instead of 

 being scattered among several as formerly. The large iron meteorite 

 from the Davis Mountains, Texas, obtained during the year, was in- 

 stalled in a floor case in Alcove 106. The bases of the glacial slabs in 

 Alcove 103 have been mahoganized and some minor changes made in 

 the installation of this alcove. All of the collections of ores of copper, 

 zinc, iron, and many minor metals have been removed from the upright 

 cases in Hall 34 and reinstalled. This removal was for the purpose of 

 tinting the interior of the cases to the uniform black color now adopted 

 for all cases. In reinstalling these collections considerable rearrange- 



