REPORT OF NATIONAL MUSEUM, 1921. 71 
have continued work on the mollusk fauna of the vicinity of Beaufort, 
N.C. The report on New Operculate Landshells of Cuba, of which 
he is coauthor with Dr. Carlos de la Torre, is now going through 
press, while work on the monograph of American Tectibranchs has 
been slowly continued. Dr. Paul Bartsch, curator of mollusks, 
has given much time to routine work of the division. Besides de- 
voting attention to numbers of groups of mollusks, as shown by 
a reference to the bibliography, considerable work was accomplished 
toward a monograph of the American shipworms, the small east 
American marine mollusks of the genera 7'riphora, Bittium, Cer- 
ithiopsis, and Metaxia; likewise the family Vitrinellidae. In the 
latter case particular stress has been laid on the examination of the 
anatomic characters. <A little time has also been given to the Philip- 
pine Nudibranch mollusks and the west American Caecidae, as 
well as the marine mollusks of the Mazatlanic faunal area. Some 
additional attention has also been given to the land mollusks of the 
Windward and Leeward Islands. Owing to the difficulty of securing 
the services of an artist, the work on the mollusks of the region about 
Beaufort, N. C., has not been completed, but it is hoped that this will 
be accomplished during the ensuing year. A new series of heredity 
experiments with Cerions has been begun in the Tortugas to replace 
those swept away by the hurricane two years ago. Mr. William B. 
Marshall, assistant curator, had but little time remaining from his 
routine curatorial duties for research, and but one paper in addition to 
that listed in the bibliography was completed and is now ready for 
the press, describing eight new species of South American naiads, 
one of them representing a new genus. Dr. Charles Wardell Stiles, 
custodian of the helminthological collections, and Dr. B. H. Ransom, 
assistant custodian, have continued their studies of the parasites of 
man and other animals. Dr. T. Wayland Vaughan, custodian of 
madreporarian corals, is still engaged in studying the Museum’s 
recent coral collections in connection with his geologic studies. 
Mr. Austin H. Clark, curator of echinoderms, during the year con- 
tinued work upon the crinoids of the Danish /ngolf expedition. 
In the division of plants the following special investigations were 
begun, continued, or completed during the year: Mr. Frederick V. 
Coville, curator, has continued his studies in breeding and propagat- 
ing the blueberries (Vaccinium), and has made frequent use of the 
herbarium as heretofore. Mr. J. N. Rose, associate curator, has con- 
tinued his studies of the Cactaceae, in collaboration with Dr. N. L. 
Britton, director-in-chief of the New York Botanical Garden, work 
which has been under way since 1911 under the auspices of the Car- 
negie Institution of Washington. The publication of volume 2 of 
the Cactaceae occurred during the past year, and volume 3 will prob- 
ably appear during the coming year. The manuscript of volume 
