The cocoa-palm is largely confined to the neighborhood of the coast, but is occasionally planted in small numbers in the interior districts, though it generally does not thrive in such situations especially on the north side of the island. On the drier southern slope of Puerto Rico, which is avoided by the royal palm, the cocoanut seems to thrive better, when it has once become established. Cocoanuts are mostly gathered while still green, for the sake of the milk or, as it is there called, the water (_coco de agua_) a popular beverage wherever obtainable. Although the local consumption of nuts for this purpose is considerable it is largely confined to the towns of the coast region. Thus it may be said that in Puerto Rico the cocoa-palm affords a luxury rather than a necessity, and that it is exceeded in economic importance by the royal palm. =Cocops= gen. nov. In a valley on the road between Lares and San Sebastian several young palms were noticed with leaves similar to the cocoanut, but smaller and finer. Finally one mature specimen was found, with both trunk and leaves strongly suggesting the cocoanut, but much smaller. The leaves are light green, the leaflets in one plane, and the fibers separating from the narrow base of the leaf. The fibers are few and flimsy, but like those of the cocoanut and other South American species of _Cocos_. The palm stood within a few feet of a small permanent brook, down which the seeds had evidently been carried and there were several young palms along the bank. The native living in an adjacent house could give us no name except _palmilla_, and seemed to think that none was necessary since the tree does not yield _yagua_ or anything else of use. Its early extermination is therefore not unlikely. In the absence of flowers and fruit[7] the relationships of the present genus cannot be ascertained nor its validity satisfactorily established. There seems, however, to be no reason for including the species in any of the genera known from Puerto Rico or other parts of the West Indies, and to associate it with Central and South American types would be a still less warrantable procedure. It is also believed that under the present circumstances the application of a name is justified by convenience of reference and that this will also assist in securing the attention of botanical collectors better than a mere allusion to “an unknown palm which may be new.” =Cocops rivalis= sp. nov.