Which of the following instruments is best suited for scribing surfaces on bones?

The instrument that is best suited for scribing surfaces on bones is the Bone Scribe. This specialized tool is designed specifically for creating precise markings on bone surfaces, which is essential during orthopedic surgeries or other procedures that require accurate alignment and placement. The Bone Scribe's sharp tip allows it to gently etch lines or markings onto the bone, helping the surgeon to visualize important anatomical landmarks or ensure proper fixation of implants.

The other instruments listed serve different purposes. A Trephine is primarily used for removing cylindrical cores of tissue or bone, often to access the medullary cavity or retrieve bone graft material. Webb Bolts are used for securing bone fragments together, not for scribing. A Drill Guide aids in accurately placing drill holes but does not create markings on the bone surface itself. Understanding the specific function of each instrument is crucial for their effective use in veterinary surgical procedures.