No. 9. — Medusae from the Maldive Islands. By Heney B. Bigelow. 



The Medusae described in the following pages were taken during 

 the exploring trip of the steamer " Amra" to the Maldive islands, carried 

 out by Mr. Alexander Agassiz during the months of December, 1901, 

 and January, 1902. I accompanied the expedition as assistant to Mr. 

 Agassiz, and during the cruise the capture and preservation of the 

 Medusae fell to my special care. The original drawings for the figures 

 accompanying this article were made on the spot, from life. 



I wish to express my gratitude to Mr. Agassiz for his kindness in 

 giving me the opportunity to visit the islands ; and also for his as- 

 sistance in the preparation of the manuscript and illustrations for this 

 paper. 



The Maldive islands, which comprise thirteen main atolls and several 

 smaller ones, occupy the greater part of a submarine plateau the area of 

 which is about thirty-five thousand square miles. The islands them- 

 selves extend from 8° north to \° south latitude; and the long axis 

 of the group nearly coincides with the 73d meridian of east longitude. 

 The peculiarly open condition of the larger atolls, especially of the 

 more northern ones, which has already been described by Mr. Agassiz 

 (Amer. Journ. Science, March, 1901), allows free access to the water 

 on all sides, and strong currents sweep through the passages and 

 lagoons in all directions. This, as is noted later, has had a considerable 

 influence on the distribution of the Medusae. During our visit, which 

 lasted from December 25, 1901, until January 22, 1902, we made sur- 

 face hauls at seventeen stations, in eleven atolls, and intermediate liauls 

 at three stations, off the easterly faces of Kolumadulu, Haddummati, 

 and Suvadiva atolls. The surface towing was done with a small net, 

 at our nightly anchorages within the lagoons. The strong currents, 

 which ran almost continuously, made it possible for us to tow when the 

 ship was at anchor, by merely lowering the net overboard and letting 

 the water run through it. 



The intermediate hauls were all made with large open nets, at depths 

 from near the surface to one hundred fathoms. We took Medusae at 



VOL. XXXIX. NO. 9 



