here the connecting medium is hyaline cartilage, a cartilaginous joint is termed a synchondrosis. An example of a synchondrosis joint is the first sternocostal joint (where the first rib meets the sternum). In this example, the rib articulates with the sternum via the costal cartilage. (The rest of the sternocostal joints are synovial plane joints.)
Sometimes, this is a temporary form of joint called epiphyseal growth plate, where the cartilage is converted into bone before adult life.
Such joints are found between the epiphyses and diaphyses of long bones, between the occipital and the sphenoid, and for some years after birth, between the petrous portion of the temporal and the jugular process of the occipital bone.