48 ART. 4. T. IKEDA : 



As in Aspidosiphon angulatus, no distinct papilla or skin-body 

 is present, except the small pores of the subdermal glands. The 

 anal shield is an elliptical and nearly flat body, covered with 

 large brown papilhie. These are composed of minute chitinous 

 granules. The caudal shield is not so thick, nor so distinctly 

 contoured as the anal shield. Its peripheral portion alone is 

 marked with small chitinous granules of a brown color. Confined 

 to the vicinity of the two shields, are the papillary bodies ; they 

 are very slightly elevated, elliptical in form, brownish in color, and 

 measure on an average 0.15 mm. by 0.09 mm. in the two diameters. 

 The papilhie (Fig. 81, PI. HI) show the same structure ns those of 

 Aspidosiphon angulatus, except in the one unimportant resj^ect 

 that the chitinous phites are in general larger than in that species. 

 The introvert is nearly as long as the body proper ; i'ts posterior 

 half is deep brown on account of the presence of spines of that 

 color. The spines (Fig. 82) are straight, sharply pointed, broad 

 at base and are formed of a thin chitinous lamina folded in a 

 funnel-like manner ; they are 0.04 mm. high in the anterior region, 

 but become gradually taller towards the introvert-basis where 

 they measure 0.07 mm. in height. These spines are distributed 

 over almost the whole surface of the introvert, l^ut are most 

 closely aggregated on the dorsal side of the posterior half of the 

 part, thus giving to this region a deeper brown color than else- 

 where. In the anteriormost parts of the introvert, there are 

 found numerous complete rows of brown colored hooks. The hook 

 (Fig. 83) is 0.05 mm. high and is provided with two sharp teeth 

 at apex. In the interspaces between hook-rows there occur small 

 colorless and transparent tubular papillse (Fig. 84) about 0.03 

 'mm. high. 



The longitudinal muscles are entirely continuous. The two 



