Mandibles- The appendages with which ants manipulate their environment. They are very variable in shape, size, and dentition, and extremely important in ant taxonomy. Margins- In full-face view, with the mandibles closed, the inner margin or border (closest to an anterior extension of the midline of the head) of each mandibular blade is the apical margin (masticatory margin), and is usually armed with teeth. Proximally, close to the anterior margin of the clypeus, the apical margin usually passes through a basal angle into a transverse or oblique basal margin. The two margins may join through a broad or narrow curve, or meet in an angle or tooth. When the mandibles are narrow of linear, the distinction between the apical and basal margins may be lost by obliteration of the basal angle. The external margin (lateral margin) of each mandible forms its outer border in full-face view and may be straight, sinuate, or convex. Dentition- The aprical margin of each mandible is usually armed with a series of teeth or denticles (short or very reduced acute teeth) or both, which generally run the length of the apical margin. If teeth alone are present, or a combination of teeth and denticles, the mandible is denate. If only tiny dentricles occur the mandible is denticulate, and if the margin lacks armament it is edentate. A natural gap in a row of teeth is a diastema and an elongate mandible with an uninterrupted series of teeth may be described as serially dentate. Teeth are usually sharp and triangular in shape but may be rounded, long, narrow, and spine-like, or peg-like. Reduced teeth or dentivles that occur between full-sized teeth are intercalary. In general the first, distalmost, or apical tooth, the one farthest away from the anterior clypeal margin, is the largest on the apical margin, although in some taxa medial or basal teeth may be the largest. The tooth at or near of the basal angle is the basal tooth the tooth immediately behind the apical may be termed the preapical, though this term may be (Bolton, B. (1994). Identificstion guide to the ant genera of the world. Cambridge, Mass., Harvard University PRess. pp.1-222).