THE GEPHYREA OF JAPAN. 29 



PHYMOSOMA NAHJENSE, n. sp. 



(Figs. 8, 59-62). 



I collected two specimens of this species, in April 1901, at 

 Naha (Naminouye) in Okinawashima, one of the Islands of 

 Riukiu. In external features they closely resemble Phymosoma 

 scolops Sel., for which species they were at first mistaken by me. 



In the larger of the two specimens, the introvert is entirely 

 protruded, the total body-length measuring 45 mm. and the 

 maximum breadth about 8 mm. (Fig. 8). The skin is of a 

 brownish yellow color, more deeply tinted at the introvert-basis 

 and at the posterior body-end. Over the entire surface there 

 are distributed tolerably large, but very slightly elevated papillœ. 

 In the middle region of the body proper, these are nearly flat 

 and elliptical in shape, measuring on an average 0.13 mm. by 

 0.10 vim. across (Fig. 59). They are thickly covered with 

 numerous round chitinous plates w^hich gradually become larger 

 towards the central area (denoted by x in the fig.) containing 

 the small aperture of the subdermal gland. The papillse gradu- 

 ally grow taller towards both ends of the body proper. In the 

 introvert-basis they are on an average 0.2 7um. high and towards 

 the posterior end of the body 0.15 mm. Hook-rows are numerous 

 and consist of small hooks, about 0.04 mm. high, which are 

 provided with a sharp and strongly curved apical tooth (Fig. 

 60). In the side view of the hook there are seen a transverse 

 bar [b) across the base and two rows of warts (rz) (" Kunzeln "). 

 Both tlie hooks and the warts are of a reddish yellow color. 



