12 ART. 4. — I. IKEDA : 



intestine. Just opposite these two points of attachment, there is 

 found a small roundish rectal diverticulum. The segmental organs 

 (so) are relatively short and small, measuring about 10 mm. in 

 length. They are transparent and almost colorless tubes, unac- 

 companied by a mesentery. Their external oj^enings are situated 

 nearly on the same level as the anus (a). The presence of the 

 dorsal vessel could not be ascertained. The tentacles, surrounding 

 the mouth, are filamentous and very numerous. 



PHASCOLOSOMA OWSTONI, n. sp. 



(Figs. 5, 39-44). 



The single specimen (Fig. 5), on which this species is based, 

 was dredged in 1899 by Mr. Owston of Yokohama from a depth 

 of 180 hiro m the Uraga Channel. It has been preserved in 

 formalin. 



The total length of the animal is 8 cm.., one-fourth of which 

 appertains to the introvert. The posterior half of the body 

 proper is wider than the anterior and measure 8-10 mm. across. 

 The entire introvert is nearly of the same thickness as the 

 anterior and narrower part of the body proper. The ground 

 color of the skin is a light blue, suffused with pink ; the middle 

 portion of the introvert is tinted a deep l)rown, and the posterior 

 portion of the body-proper a light brown. The body-wall is in 

 the body proper relatively thin, smooth on the external surface 

 and more or less transparent, while in the introvert it is thick, 

 opaque and has a closely wrinkled surface. All over the sur- 



