290 



T. IWAKAWA. 



ventral plate of adult female is sinuated at the middle of the hind margin, 

 and has either a Y-shaped or a quadrangular groove near the front margin of 

 the surface (Pl. XI, fig. 2, A, B); in younger female no such groove can be 

 seen, there existing only two streak-like ones on the sides of an imperfect 

 median groove (fig. 2, C, D). In the male the same ventral plate has 

 truncated hind edge and shows a wide but shallow depression on the sur- 

 face at the hind end of the median line (fig. 2, E). The trochanter of 

 maxillary palpus possesses five marginal teeth on the upper surface in both 

 sexes, but in male the first or the outermost tooth is much stronger than 

 other teeth (fig. 3, B), while in female the second is the strongest, instead 

 of the first, which is much smaller (fig. 3, A). The tibial apophysis in 

 male is crooked and knobbed ; the minute teeth on this knob are divided 

 into two sets (outer and inner) by an incision which receives the tip of the 

 movable finger, and the outer set touches the inner side of the immov- 

 able finger. The hand of male is suddenly reduced in size towards the 

 fingers, and the serrulated inner margin projects as an immovable finger 

 from the hand at an obtuse angle. The hand of female tapers gradually 

 towards the extremity, and the immovable finger projects gradually from 

 the inner angle of the hand, running parallel with the tibial apophysis 

 (fig- 3)- The eighth and ninth joints of the tarsal flagellum of adult 

 female are black on the lower side, and each has a deep indentation near 

 the base, but in young female the joints are simply cylindrical and not black 

 in color. L. 31-42 mm. 



Habitat: Loochoo, Formosa, Hongkong. 



