The genus Japyx has been of particular interest because of the apparent absence of rudimentary abdominal appendages. One American* writer says very decidedly. “Japyx has none”; a well-known English † writer considers these appendages as “represented by mere groups of stiff hairs.” The presence of these appendages was indicated as early as 1869, by Brauer, ‡ in his description of Japyx gigas. In 1889 there appeared a very important paper by Haase§, in which the rudimentary appendages are distinctly shown. These appendages can easily be seen in either of the species described below.