NARES ABYSSAL PLAIN: South and southeast of the Bermuda Rise lies the Nares Plain, a 37,000-square-mile abyssal plain that slopes eastward from Vema Gap toward the Mid-Atlantic Ridge. From 62° to 64° W. its northern and southern boundaries are abrupt, and only three or four small abyssal hills have been observed in the plain. East of 64° W. the gradient of the plain exceeds 1:2500, and the frequency of hills increases until at 61° W. the plain consists of a series of fingers which extend into the abyssal hills. The sediment cores obtained in the Nares Abyssal Plain consist of alternating red clays and quartz silts (Ericson _et al._, 1952; in press). The Nares Abyssal Plain is the deepest of the broad abyssal plains of the ocean-basin floor. It is also the farthest from the land. If the turbidity currents smoothed the Nares Plain they would all have had to flow through Vema Gap since the outer ridge-trench complex to the south prevents currents from this area from reaching the Nares Abyssal Plain. The idea of a route through Vema Gap is supported by the fact that the plain slopes eastward from the gap. HISPANIOLA-CAICOS ABYSSAL PLAIN: The depression between the Bahamas and the coasts of Cuba and Hispaniola deepens east of Cay Lobos and reaches its maximum depth of 2220 fathoms northwest of Cape Francis Viejo of Hispaniola. At Cay Lobos the channel is a steep V-shaped depression with a maximum depth of 400 fathoms, but to the east this V-shaped channel opens out to an abyssal plain about 1500 fathoms deep. Between this point and Great Inagua Island the flat floor slopes east reaching a depth of 1575 fathoms just southwest of Inagua. This portion is called the Old Bahama Abyssal Plain. South of Great Inagua is another V-shaped channel in which the depth drops from 1700 fathoms on the west to 2200 fathoms on the east. From this point to Cape Francis Viejo the Hispaniola-Caicos Abyssal Plain is nearly flat. Sediments collected from this plain confirmed the turbidity-current origin of the smooth topography. The cores contained plant debris, shallow-water fossils, and a variety of reworked older material (Ericson, Ewing, and Heezen, 1952; Ewing and Heezen, 1955; Ericson _et al._, 1955).