A: Carpals (wrist)
B: Metacarpals (palm)
C: Phalanges (fingers)

1: Synovial joint: Plane (= gliding).
It is situated between the carpal bones. The only movement allowed is gliding. This is characteristic of the plane joint. The articular surfaces of adjacent bones are flat.
2: Synovial joint: Plane (= gliding).
It is situated between the carpals and the metacarpals of the digits 2 to 5. The only movement allowed is gliding. This is characteristic of the plane joint. The articular surfaces of adjacent bones are flat.
3: Synovial joint: Saddle.
It is situated between the carpals and the metacarpals of the first digits. The movements allowed are flexion/extension, adduction/abduction and circumduction. Both saddle and condyloid (= ellipsoidal) joints allow such movements. However the shapes of its articular surfaces classify it as a saddle joint: One bone's articular surface is concave in one direction and convex in the other while the second bone is just the opposite .
4: Synovial joint: Condyloid (= ellipsoidal).
It is situated between the metacarpals and the proximal phalanges of the digits 2 to 5. The movements allowed are flexion/extension, adduction/abduction and circumduction. Both saddle and condyloid (= ellipsoidal) joints allow such movements. The shapes of its articular surfaces classify it as a condyloid joint: one bone's oval convex surface fits into the oval concavity of the adjacent bone.
4: Synovial joint: Hinge.
It is situated between phalanges. The only movements allowed are flexion/extension. This is charateristic of the hinge joint.