64 REPORT OF NATIONAL 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 particularly 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 work 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 and 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 until 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 
