THE GEPHYREA OF JAPAN. 



57 



except in the facts that the main tentacular stems are constantly 

 four in number (instead of 5 or 6) and that the hooks are entirely 

 wanting in all the specimens. There occurs on the rectum a 

 distinct blind diverticulum such as has not been noticed in any 

 species of Dendrostoma yet described. 



DENDROSTOMA MINOR, n. sp. 



(Figs. 16, 92-95). 



This species is a small form, not exceeding 15 mm. in length 

 and 3 mm. in breadth. The introvert is one-third as long as the 

 body proper. The worms in the fresh state are of a yellowish 

 brown color, only the anterior portion of the introvert being of 

 a light violet tint. The whole surface of the skin is covered 

 with small papillœ which are nearly flat in the middle main 

 region of the body proper. But in the anterior and posterior 

 regions, the papillœ are somewhat raised and appear as oval 

 tubercles of 0.02-0.03 mm. height and 0.10 mm. long diameter 

 (Fig. 92). They are formed of numerous polygonal chitinous 

 plates which are larger towards the center of the papillae ; one 

 plate in the center contains the opening of the subdermal gland. 

 In the hooked region of the introvert, the papillœ are much 

 smaller, but are of nearly the same height, appearing like a 

 hemispherical tubercle resting upon a broader basal elevation 

 (Fig. 93). Hooks, about 50 in number, are found scattered in 

 the anterior parts of the introvert (Fig. 94). They are 0.04 mw. 

 high, blackish brown in color, slightly curved and bluntly pointed 

 at apex. Specimens from Funakawa in the province of Ugo (on 



