64 EEPOET OF ITATIONAL MUSEUM, 1921. " 



terial have been identified and incorporated. This places the east 

 coast collection in good order and easily, available for study. Much 

 time has been devoted to classifying the Philippine collection ac- 

 cording to genera and species and arranging it in systematic order. 

 In the course of identifying material sent in by outside correspond- 

 ents a considerable portion of the collections has been arranged ac- 

 cording to most recent classifications. This is j)articularly true of 

 the west coast mollusks. Rearrangement of the collection of Ameri- 

 can shipworms is well under way, with a view to a monograph in the 

 near future. Since last February the time of one man for one day 

 each week has been devoted to the alcoholic mollusk collection. In 

 all cases where necessary new containers have been supplied and the 

 older ones refilled. This Avork is progressing satisfactorily. Micro- 

 scopic slides of molluskan odontophores to the number of 724, be- 

 longing to the Thaanum collection and prepared by the late Rev. 

 R. Boog Watson, were registered and numbered by the use of a dia- 

 mond point. All defective slides were put into good repair. As may 

 be judged, the addition of so many slides has greatly enhanced the 

 already valuable collection of anatomical preparations belonging to 

 this division. A number of slides of odontophores and of the 

 glochidia of several species of naiad have been made as an addition 

 to our collection of microscopic slides. The reclassification and reno- 

 vation of the general recent collection have been continued through- 

 out the year. The North American fresh-water univalves and the 

 great and difficult families Turbinidae and Trochidae, among the 

 marine shells, were gone over in this way. The labeling an,d register- 

 ing of the great Thaanum collection of shells, most of which came 

 from the Hawaiian Islands, have been completed. Identification of 

 Philippine marine mollusks secured by the Albatross during the 

 cruise of 1907-1910 has been continued. As time goes on, more and 

 more of our material is being thoroughly identified, and great prog- 

 ress in this respect has been made throughout the collection, espe- 

 cially in Hawaiian material, Philippine material, and in material 

 from the east coast of North America and the West Indies and land 

 and fresh-water mollusks from South America. The writing of head 

 labels for the species in the collection has been progressing during 

 the year imtil now a large part of all the collections in our charge 

 is furnished with these labels, adding greatly to convenience in con- 

 sulting them. It seems appropriate to mention at this time the vast 

 amount of time and labor saved by the use of the label holders and 

 blocking-sticks equipped with brass clips. Our collection is growing 

 so rapidly it is estimated that the entire time of at least one person 

 is saved by the use of these small inventions, making it possible for 

 us to keep current the work of the division without asking, to date, 

 for additional assistance. The economy of space in our storage cases 



