Hemidactylium - hemi- lateral half (Latin); dactylus, having many toes or fingers (New Latin, and Greek).
scutatum - scutatus, armed with a shield (Latin). This is derived from the costal grooves on the side of the body which resemble overlapping plates.
Only four toes on each foot!
Although most salamanders have 5 toes on their hind feet, this species and the mudpuppy have only 4 toes. A constriction at the base of the tail enables their tail to come off when grabbed by predators.