74 Report of the President 



During the summer, Dr. Lutz continued his important ento- 

 mological survey of the region west of the one hundredth 

 meridian, chiefly in the Red Desert and Jackson Hole regions 

 of Wyoming. Collections were also made in Colorado, Idaho, 

 Utah and Indiana, practically completing the survey as planned 

 for Colorado and its immediate borders. The many specimens 

 resulting from the trip have been mounted and for the most 

 part identified, while reports on the insects of the Southern 

 Rockies are in course of preparation. Mr. Watson's field 

 work in Jamaica, mentioned in last year's report, was com- 

 pleted as planned, and the liberality of Mr. B. Preston Clark 

 will make it possible to continue this phase of the West Indian 

 work in Haiti, possibly during the winter of 1921-1922. Mr. 

 Miner's field work during the year has been confined to local 

 collecting, especially in Southern New Jersey, where, with the 

 cooperation of Mr. Frank J. Myers, studies are being made of 

 rotifers for the proposed Rotifer Group. 



The new Bryozoa Group, which was practically completed 

 during 1919, was installed early in the year and placed on 



exhibition the latter part of February. This ex- 

 Hair" 11 ^fini, P re P arec * by Messrs. Herman O. Mueller, 



Show Shimotori and Chris E. Olsen, under Mr. 

 Miner's direction, represents two square inches of sea bottom, 

 magnified twenty-five diameters, or more than 15,000 times. 

 It depicts the rich abundance and diversity of the minute 

 animals and plants of the sea bottom. 



An exhibit was also installed illustrating the distribution 

 and variation of the land mollusk Partula, as exemplified in 

 the Pacific island, Tahiti, of the Society Group. The mollusks 

 of this genus are abundant in the numerous valleys of the 

 Island, where, through isolation, varieties peculiar to certain 

 areas have been evolved. The exhibit consists of a large relief 

 map of Tahiti, with mollusk specimens representing the range 

 of variation, displayed in their appropriate valleys. Two stages 

 in the subsidence of volcanic islands and the evolution of the 

 coral atoll, according to Darwin, are also illustrated by this 

 relief map, in connection with a second, modeled to show the 

 islands of Raiatea and Tahaa, also of the Society Group. The 



