1 88 W. C. ALLEE. 



It is true that analysis of the results of preliminary collecting 

 showed the same relations as the quasi-quantitative analysis of 

 more complete records in the Woods Hole region. Unfortunately 

 one cannot be sure that the animals found in such preliminary 

 work are really the typical animals since they may obviously 

 contain many incidental forms. In other words in a random 

 sample one is more apt to collect animals typical of the habitat 

 than incidental forms but he can never be sure of this without 

 further work. 



V. The Effect of Continued Collecting on 

 Distribution Records. 



In 19 1 7 when the collecting records were first studied seriously 

 there were 181 species in the catalog. In 1920 when a similar 

 study was made, the catalog listed 242 species. In the interim 

 the Sound Gutters, Lackey's Bay and Great Harbor had been 

 added to the localities visited. 



In 1917, 11 species were recorded only from the wharf pilings. 

 The later lists show 7 species so limited but this includes only 

 one (Tetrastemma) of the previous list. In 1917 two species 

 were recorded only from rocks or rockweeds, while on the later 

 list there were 10 such species including only Clava leptostyla 

 from the preceding list. In the first comparison there were 10 

 animals recorded only from dredging; in the later one, 13, which 

 includes four of those on the preceding list: Area ponder osa, 

 Strongylocentrotus droebachiensis, Heterocrypta granulata, and 

 Amaroecium stellatum. 



On the 19 1 7 list, 71 species were recorded from the flats only. 

 After four more years' work this had shrunk to 41 providing 

 animals found in the sand under and among rocks are excluded. 

 Of these only 17 appear on both lists. They are: Edwardsia 

 elegans, Eloactis producta, Bdelloura Candida, Syncoelidium 

 pelhicidium, Ophioderma brevispina, Chaetopterus pergamentaceous , 

 Platynereis megalops, Scoloplos acutus, S. robustus, Spio (setosa?), 

 Callianassa stimpsoni, My sis stenolepis, Squilla empusa, Melampus 

 lineatus, Clidiophora trilineata, Pecten irradians, and Tellina 

 tenera. 





