Cook's Petrels were seen in small numbers. Sooty Terns became the dominant bird in area B with Leach's Storm Petrel still common and a scattering of shearwaters and petrels. The greatest number of birds were seen near 10°N. On the return trip along 126°W, the species composition did not change much, but large numbers of birds were seen from 3°-10°N instead of being concentrated in one small area. Areas C and E were similar in species composition with the Sooty Tern still the dominant species and Leach's Storm Petrel decreasing. Shearwaters and petrels were almost absent from these areas. On each leg there were concentrations of birds between 10°S and 15°S. A secondary concentration was found at 7°S on the eastern leg, and at 3°S on the western leg. Area D had only a few terns and shearwater-petrels. The abundance of birds this trip does not appear to correlate very well with the current system in the region. The Equatorial Countercurrent was found between 2°N and 6°N this trip. On the eastern leg birds were most abundant north of the Equatorial Counter- current with very few birds at the edges or in it. While on the western leg they were common north of it, south of it, and in it. The secondary concentrations of birds in the Southern Hemisphere were not related to any special feature of the ocean currents, with all of them lying in the South Equatorial Current. There was one interesting relationship with the Countercurrent. If we plot the number of shearwater-petrels seen per day (figure 3) and then delineate the area of greatest abundance (i.e., more than ten birds per day) it can be seen that the southern boundary of this area is also the southern boundary of the Countercurrent. This relationship is even more