THE GEPHYREA OF JAPAN. o9 



slightly larger in the region of the caudal shield. Very numer- 

 ous rows of very small hooks with incompletely bifurcated apex 

 and bearing warts ("'Runzeln") at base. Small spines are scattered 

 to a wide extent behind the hook-rows. Longitudinal muscles 

 partially divided into irregular, frequently anastomosing bundles, 

 which are however more or less regularly developed on the in- 

 side of the anal shield. Retractor muscles spring with two roots 

 from the inside of the caudal shield. Intestinal double spirals 

 are travei'sed by a spindle-muscle fixed at both ends to the 

 body-wall. Rectal diverticulum distinct. Segmental organs long 

 and large, attached to the body- wall by mesenteries throughout 

 nearly their entire length. 



Several specimens of this species were collected by Mr. 

 MiYAJiMA (1900) and by myself (1901) in Okinawashima (Naha) 

 and Amami-Oshima (Koniya). The largest specimens in the fully 

 extended state measure 5 cm. in total length. In the preserved 

 state, the larger ones have a yellowish brown color and the smaller 

 a light reddish yellow color. The anal and caudal shields are 

 of a deep brown. 



The external features and the anatomical characters agree 

 well with the description given by Selenka. What slight dif- 

 ferences seem to exist, are as follows : 



On the concave side of the hook, just at the base of the 

 small accessory tooth, a few very fine, thread-like processes of 

 chitin are produced inwards from the spot mentioned (Fig. ^^). 

 Between hook-rows there are scattered small tubular papillœ 

 (Fig. 67). Each papilla rests on a low basal prominence which 

 is covered with relatively large chitinous granules {x). 



The worms live in dead coral masses or in eroded coral rocks. 



