PROCEEDINGS OF THE UNITED STATES NATIONAL MUSEUM 



issued \\m,ik S CfiMti ^H '^* 



SMITHSONIAN INSTITUTION 



U. S. NATIONAL MUSEUM 



Vol. 83 Washington : 1936 No. 2993 



A COMPARISON OF THE SHALLOW-WATER SPONGES NEAR 

 THE PACIFIC END OF THE PANAMA CANAL WITH 

 THOSE AT THE CARIBBEAN END 



By M. W. deLaubenfels 



Pasadena, Calif. 



During the summer of 1933 I made a study of the intertidal sponge 

 fauna at each end of the Panama Canal. ^ Specimens were collected 

 from intertidal waters or from waters barely below low tide, entirely 

 without dredging. The method most frequently employed was 

 wading and collecting by hand, but in some cases an ordinary garden 

 rake was used from a rowboat. 



The sponges of the deeper ocean differ radically from those in 

 intertidal and shallow waters. This has been well brought out by 

 various authors, particularly by Burton (1928). Seldom do sponges 

 from one of these habitats venture over into the other. In general 

 the sponges of the deeper waters of one ocean are related to those in 

 other oceans from similar depths rather than to the adjacent shallow- 

 water forms. The latter are likely to show more regional or local 

 specializations than are sponges from greater depths. It was there- 

 fore deemed more important to compare the shallow-water sponges 

 from the Atlantic end of the Panama Canal with those from the Pacific 

 end than to make any effort to collect sponges from deeper waters 

 farther out on either side of the isthmus. 



I Thanks are clue to Dr. James Zetek, of the U. S. Bureau of Entomology and Plant Quarantine, and to 

 various other officials connected with the Government staff in the Panama Canal Zone who made it possible 

 to carry on the collecting and locate suitable places for finding spongas, and to officials of the U. S. National 

 Museum, especially Dr. Alexander Wetmore and Dr. Waldo L. Schmitt, for help and cooperation. 



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