Field Work for Invertebrates 75 



Curator Crampton, after a brief period of field-work in the 

 Yosemite Valley during the early summer, proceeded to the 

 Society Islands in Polynesia, for the purpose of 

 Field Work completing certain field investigations on varia- 

 tion, distribution and evolution in the case of 

 the land mollusks of the genus Partula. Work was carried 

 on mainly in Moorea, an island near Tahiti, with results far 

 beyond expectation in their value and significance. The 

 volume dealing with the Moorean species and their progressive 

 evolution under natural conditions is nearing completion. Dr. 

 Lutz took the field in the prosecution of the survey west of 

 the 100th meridian, a line of work that was initiated in 1916 

 by studies in the vicinity of Tucson, where there are moun- 

 tains somewhat isolated by plains of the Lower Sonoran 

 faunal area. This year nearly three months were spent by 

 Dr. Lutz in Colorado, who obtained material from a number 

 of localities ranging from typical Upper Sonoran plains to 

 the snow line. This work was made possible partly by the 

 generosity of Dr. Pearce Bailey ; and Dr. Lutz had the volun- 

 teer assistance of Messrs. Herbert F. Schwarz and Pearce 

 Bailey, Jr. More than 23,000 specimens were secured, and 

 these have all been mounted and will soon be ready for study. 

 In our chosen field of the West Indies, through the generosity 

 of Mr. B. Preston Clark, Mr. Watson is engaged in supple- 

 menting the work done by Mr. Grossbeck in Jamaica. As Mr. 

 Grossbeck's collecting was done in early spring and Mr. 

 Watson visited Jamaica in December, we are certain to secure 

 most interesting additions to our material from this island, 

 which is, to some extent, the key to the problems concerned 

 with distribution in the West Indies. Mr. Arthur Jacot spent 

 a month during the summer in field-work in the vicinity of 

 New York, collecting an extensive series of the marine and 

 fresh-water Mollusca from characteristic localities of the 

 neighborhood. 



