Apical - the scale or scales lying at the tip of the snout, in contact with the rostral scale.
Canthal - the scale or scales which constitute the Canthus rostralis
Canthus rostralis - area between the supraocular and the rostral which forms a prominent ridge on both sides of the snout.
Circumoculars - scales bordering the eye (see also perioculars).
Dorsal - scale or scales which cover the snake´s body.
Frontal - plate or scale lying on top of the head between the supraoculars.
Gular - Pertaining to the throat region or ventral surface of the neck.
Infralabials - the series of scales along the lip of the lower jaw, exclusive of the mental scale.
Keeled - used in reference to scales that possess a median ridge. All viperids have keeled scales.
Mental - triangular scale at the anterior edge of the lower jaw or chin.
Paraventrals - scales composing the first row of dorsal scales on either sides of the ventrals.
Parietals - a pair of large scales on the back of the dorsum of the snake´s head. In most vipers the parietals are fragmented into many small scales.
Perioculars - scales bordering the eye.
Pholidosis - account and arrangement of the scales on a reptile.
Plates - large flat scales on top of the snake´s head or belly.
Preventrals - scales lying anteriorly in the ventral series, but not in contact on both sides with the paraventral row of dorsal scales.
Rostral - vertical scale covering the anterior tip of the snout in the upper jaw.
Subcaudals - scales lying on the ventral side of the tail, immediately after the cloacal plate.
Supralabials - the series of scales along the lip of the upper jaw, exclusive of the rostral scale.
Supraocular - placa situada en la parte superior de cada ojo.
Ventrals - elongated plates or scales covering the belly from the neck to the cloacal plate.
Viperid - viper, a snake in the family Viperidae.