What's the difference between circlet and circulet?

Circlet

Definition:

(n.) A little circle; esp., an ornament for the person, having the form of a circle; that which encircles, as a ring, a bracelet, or a headband.
(n.) A round body; an orb.
(n.) A circular piece of wood put under a dish at table.

Example Sentences:

(1) The concept of a neurovascular pyramid with its base at the distal metaphysis and of a periosseous tendinous circlet at that level implies a search for a compromise between the stability of the assembly and the dangers of the method.
(2) Fusion takes place in a particle-free zone which is surrounded by a circlet of particles on the P face of the plasma membrane and an underlying circlet of particles on the P face of the acrosomal vauole membrane.
(3) A circlet of 9 interacting microtubular doublets generates less bending moment at low bending rates, but allows bending moment to be generated at higher bending rates, and has an energy efficiency at least 92% as great as an arrangement with all the interactions between microtubular doublets in a plane parallel to the bending plane.
(4) Among the principal ultrastructural changes in peroxisomes of male rat liver were (a) cavitation and compartmentalization of the matrix, often giving the appearance of a peroxisome-within-a-peroxisome, and (b) narrow, dense extensions of canaliculi or cisterns from the periphery of the peroxisome, forming partial circlets or surrounding irregular areas of cytoplasm.
(5) Regime change began according to legends of the battle when on a hill overlooking the battlefield, Henry Tudor was crowned with the circlet which fell from Richard’s dying head.
(6) The first IMP row is organized in a membrane circlet lacking of f-c complexes, whereas the new shaft membrane in the middle of the circlet exhibits numerous complexes.
(7) These circlets of particles are present before induction.
(8) This number is more than would be needed to surround each flagellar basal body with a single circlet of MotA protein; possible interpretations of the result are discussed.