DEPARTMENT OF MARINE BIOLOGY. 167 



material was brought up from different levels below 50 feet, and the corals 

 from near the bottom of the reef did not have the appearance of having under- 

 gone any more extensive chemical changes than had that from considerably 

 less depth. 



The samples of this material shipped to Princeton for more careful examina- 

 tion and analysis have not as yet been received, so that no data on the extent 

 and character of the changes that the coral has undergone are available 

 except those obtained in the hasty examination made when the specimens 

 were taken from the drill and packed for shipment. 



The deepest boring (125 feet) was made at a point a little more than half 

 (0.57) of the distance from the shore to the reef edge, so that by itself it would 

 afford no evidence on whether or not the fringing reefs about Pago Pago 

 Harbor are built up on the sloping sides of the old crater or upon a platform 

 cut into the shore in the Tertiary era. When the results of our borings are 

 considered in connection with the fact that when constructing the founda- 

 tion for the cold-storage plant of the United States naval station at Pago 

 Pago (which is situated within 100 feet of a lava cUff) a depth of 116 feet was 

 reached before a solid substratum was found, it appears more probable that 

 a fairly level platform exists beneath these reefs than that they have been 

 formed on the natural slope of the shores. 



ALCYONARIAN FAUNA OF REEFS ABOUT VITI LEVU. 



The alcyonarian fauna of the reefs about Viti Levu is very much richer 

 in species than that of the Samoan reefs. Tubipora and other forms with a 

 massive skeleton are abundantly represented. Several undescribed forms, 

 showing in different degrees the transformation from the Sarcophytum type 

 to that of Lobophytum, occur over many of the reefs where with Xenia and 

 nephthyids they cover immense areas of bottom on the inner sides of the 

 barrier reefs, which in the region about Suva he parallel to the general shore- 

 line at a distance of not more than a mile. On many of these reefs the Alcyo- 

 naria appear to constitute an even more important element of the present 

 reef fauna than on the Samoan reefs. In the elevated Tertiary hmestones, 

 found in several places about Suva Harbor, the skeletons of an alcyonarian 

 resembling Heliolites was found in a recognizable condition perhaps more 

 commonly than the remains of any other ccelenterate. 



Although in the short time at our disposal in this region no extensive study 

 of the reefs could be attempted, specimens constituting a comprehensive 

 growth series of the most important forms were photographed, weighed, 

 measured, and cemented out on the reefs near their original locations. 



THE OXYGEN CONTENT OF THE SURFACE-WATER OF THE PACIFIC OCEAN. 



The following observations on the oxygen content of the surface-water in 

 the Pacific Ocean were made on voyages from San Francisco to Pago Pago, 

 June 19 to July 1, 1918; from Apia, Samoa, to Suva, Fiji, August 9 to 13, 

 1918; from Suva to Vancouver, British Columbia, September 6 to 19, 1918; 

 and in Pago Pago Harbor during July 1918. Although the data have not as 

 yet been cafefully compared with the calculated solubihties of oxygen in sea- 

 water of like temperatures and salt content, it seems probable that the amount 

 of dissolved oxj'^gen in Pacific surface-water approximates very closely the 

 expectations founded upon this basis. The only marked departure from this 

 apparent agreement was observed in the region 5° north of the equator, where 

 an easterly current was encountered. The oxygen content of the water in 

 the easterly current was considerably higher than that of water of the same 



