The mouth of the fish faces downward and has wide lips that contain papilla. All members of "Syndontis" have a structure called a premaxillary toothpad, which is located on the very front of the upper jaw of the mouth. This structure contains several rows of short, chisel-shaped teeth. In some species, this toothpad is made up of a large patch with several rows in a large cluster. In other species of "Syndontis", this toothpad is clearly divided into two separate groups, separated by a thin band of skin that divides the toothpad. This character is used as a method of differentiating between two different but similar species of "Syndontis". In "S. granulosus", the toothpad is uninterrupted, or continuous without a break. On the lower jaw, or mandible, the teeth of "Syndontis" are attached to flexible, stalk-like structures and described as "s-shaped" or "hooked". The number of teeth on the mandible is used to differentiate between species; in "S. granulosus", there are 28 to 51 teeth on the mandible, arranged in a single row.