(a) : Fronto-parietals are a pair of long, broad, flattened and membranous bones. They are united along the mid-dorsal line and form the whole roof of cranium. In larval frog, each fronto-parietal occurs into separate frontal and parietal parts, but in adult frog, they become fused to form a single fronto-parietal. The entire floor of cranium is covered and strengthened by a large parasphenoid bone.