1 68 W. C. ALLEE. 



course, but the records here used have been kept from the begin- 

 ning by myself with the occasional help of other staff members. 1 



The records are based on the bi-weekly collecting trips of the 

 Invertebrate Class and cover most thoroughly the period from 

 about June 20 to August 15. These trips have been supple- 

 mented by expeditions made by instructors and by special trips 

 for particular observations. 



The organization of field work for eight years has been to 

 divide the class into as many collecting teams as there were 

 instructors. One person from each team was appointed recorder 

 for the day and was supplied with a list of all the animals previ- 

 ously taken from the locality under consideration. The animals 

 found were recorded according to habitats. The complete list 

 for the year was made up from these combined records. 2 



1 The following people have been at one time or another members of the in- 

 structing staff of the Invertebrate Course and have contributed to the data on 

 which this series of papers is based. Without their cooperation this work could 

 not have been done. Caswell Grave, Raymond Binford, E. J. Lund, George A. 

 Baitsell, T. S. Painter, F. M. Root, W. J. Kostir, Robert H. Bowen, C. L. Par- 

 menter, G. S. Dodds, Robert Chambers, Jr., Ann H. Morgan, W. J. Crozier, 

 Donnell B. Young, J. P. Visscher, J. A. Dawson, Christianna Smith and E. A. 

 Adolph. 



1 am indebted also to Mr. G. M. Gray for much valuable aid and friendly 

 assistance; to Dr. Mary J. Rathbun for identification of the Brachyura; to Mr. 

 Waldo L. Schmidt for similar service with the Anomura and Macrura; to Mr. 

 Clarence R. Shoemaker for similar service with the amphipods and isopods; to 

 Professor E. S. Morse for assistance with some of the molluscs and to Professor 

 Raymond Osburn for assistance with the Bryozoa. 



2 The formal record of collecting experience has been recorded in abbreviated 

 form on library cards which are deposited in the Library of the Marine Biological 

 Laboratory. An annotated catalog of the distribution has been prepared as 

 Study II. of this series and deposited with the library of the U. S. Fish Commission 

 who have kindly agreed to furnish copies to the libraries of the Marine Biolog- 

 ical Laboratory at Woods Hole; the Museum of Comparative Zoology at Cam- 

 bridge, Scripps Institution at Lajolla; the United States National Museum at 

 Washington and to the Harpswell Laboratory at Mount Desert Island, Maine. 



The catalog shows the littoral invertebrates collected during the years 1915-1921 

 inclusive. Each locality in which an animal has been taken is recorded. The 

 number of years which it has been found in a given locality is shown and an index 

 figure of comparative abundance is also given. Where possible and desirable the 

 location of particularly favorable collecting grounds is given with some exactness. 

 This elaborated catalog forms the basis from which the facts presented here are 

 drawn and together with the present report gives the background for the two 

 following studies. 



