The relation of seismology to the study of the island‐arcs is nowhere better illustrated than in the West Indies Region. The study should include the northern part of South America and part of Mexico. The peculiar significance of the Caribbean Sea with little activity in its central basin completely surrounded by regions of earthquake‐activity presents a problem which is duplicated only in the region to the east of a line joining Japan and the Philippine Islands.The special problems of the region include: The geological significance of the closed loop and especially the geological conditions in Central America and Ecuador and Colombia where the two parts of the loop separate; the significance of earthquake‐activity in the Bartlett Deep and also in the Nares Deep; the relation of the seismic activity to the as yet inadequately known submarine contours in the Windward Islands Region and the relation of seismic and volcanic activity in the same region. Others might be added, but these suffice to give the type of pro