There are eight of them altogether, and they can be thought of as forming two rows of four.
Proximal Row Scaphoid (or navicular) - this bone, with the lunate, articulates with the radius of the arm. Lunate - articulates with the radius and the capitate. Triquetrum - on the ulnar side of the hand, but does not articulate with the ulna. Pisiform - a sesamoid bone that lies anterior to (closer to the palm than) the triquetrum. Distal Row Trapezium - the most lateral bone of this row. It articulates with the metacarpal of the thumb. Trapezoid - articulates with the 2nd metacarpal. Capitate - articulates with the metacarpal of the middle finger. Hamate - articulates with the metacarpals of the 4th and 5th fingers. It has a projection called a hook.
