58 REPORT OF NATIONAL MUSEUM, 1922. 



The animals used for experimentation are land mollusks of the genus 

 Cerion. In this connection he has been working upon a survey of the 

 distribution of the native species in the Florida keys. In this sur- 

 vey he has always used the ordinary method of approaching the 

 keys — that is, by means of a launch — and then examining them for 

 grassy plots, for it is in these that these animals find a suitable 

 habitat. To make sure that all such locations in the keys have been 

 examined and not missed is quite an arduous task, because in many 

 instances the keys are fringed with mangroves, and one would never 

 suspect that grass plots existed in their interior. A survey of this 

 kind, therefore, is a tedious undertaking, requiring a great amount 

 of time. By the use of the seaplane, which the Navy Department 

 was kind enough to detail to him, Doctor Bartsch was able to fly at 

 a low altitude over all the keys from Miami to the Tortugas, over 

 the entire Bay of Florida from West Cape to the eastern limit of 

 the keys, and make notes on and charts of all the grass plots seen. 

 Doctor Bartsch believes that it would have taken a year to have 

 accomplished this \sy the old method, and they finished it all in a 

 period of four days. Now, it will be possible, by means of the 

 marked charts, to follow up this reconnaissance survey with the 

 actual work of examination without loss of time or danger of miss- 

 ing colonies. 



In order to obtain living specimens of the Helicid genus 

 Thysanophora for anatomical study toward a proposed monograph 

 of the group, John B. Henderson, a regent of the Smithsonian In- 

 stitution, made a rather hurried trip to Jamaica to personally col- 

 lect the necessary material. This little expedition proved unusually 

 successful and of great benefit to the work in hand, as well as to the 

 mollusk collections. 



As usual, important material has been received from the Bureau 

 of Fisheries and from the Biological Survey, United States Depart- 

 ment of Agriculture, representing the results of work carried on 

 under these branches of the Government. 



The National Herbarium has been enriched by the results of two 

 expeditions of first importance. Early in December, 1921, Paul C. 

 Standley, assistant curator in the division of plants, was detailed by 

 the Museum to carry on botanical exploration in Central America, 

 the expenses of the field work being borne mainly by the Gray 

 Herbarium, the New York Botanical Garden, the Bureau of Plant 

 Industry, and Oakes Ames, the latter being especially interested in 

 the orchids of this region. About five months was spent in El Sal- 

 vador, working from San Salvador as headquarters, where very great 

 assistance was rendered by the staff of the Direccion General de 

 Agricultura. Incidentally a small collection was made on Tigre 

 Island, Honduras. Nearly one month was spent in Guatemala, prin- 



