REPORT OF NATlOiSTAL MUSEUM, 1921. 71 



have continued work on the molhisk 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 Triphora, 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 wdth 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 liis 

 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 crinoicls of the Danish /w^oZ/ 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 



