THE NAUTILUS. 



VOL. XXVI. MARCH, 1913. No. 11 



COLLECTING IN PANAMA. 



BY EUGENE W. PRESBREY. 



In 1850, C. B. Adams, Professor of Zoology in Amherst College, 

 spent six weeks collecting in llie waters of Panama Bay. In 1852, 

 under his own direction, he published a complete catalogue of species 

 collected, with careful notes on synonymy, stations and number of 

 each species taken. 



The writer recently spent two weeks covering carefully exactly 

 the same territory, from Old Panama to Taboga Island, about fifteen 

 miles. It may interest the readers of THE NAUTILUS to know what 

 changes in numbers, stations and characteristics may occur in sixty- 

 three years. Many changes have occurred, due probably to dis- 

 turbed environment. Adams, in six weeks, took 41. 35 specimens, 

 51G species! ! Of these there were 38,920 Gasteropoda, 376 

 species! ! In the same season of the year, from the same rocks and 

 sands, with the same tides eighteen to twenty-four feet the writer, 

 in two weeks, under most favorable conditions, was able to find only 

 112 species of Gasteropoda, and about 1000 specimens. Some of 

 these species were not found at all by Adams, who was a careful 

 collector, letting nothing escape him, not even numbers. But the 

 peculiar and interesting fact is that few of the species found in great 

 numbers by Adams are plentiful now, and many of those species are 

 not to be found at all. In many stations other species have taken 

 the place of those found by him. 



Adams collected 4oOO Oliva volutella. These are not there now. 

 Two dead on the beach, and one alive, were all that I found. Of 



