[An abnormally formed Ctenophthalmus assimilis assimilis (siphonapteres hystrichosyllidae)]

A female flea is described the body of which is abnormally formed and compressed. It is characterized by a split along its back, raised up abdominal segments and by a shortening of its head. These anomalies might be explained by longitudinal compression of the body during pupation. The possibility of a mutation is not excluded.