22 Ar t- 9- — M - Yeri and T. Kaburaki : 



the shell-gland passage (sgp). The former is of a tubular shape, its 

 blind hind end lying at a position dorsal to the anterior end of 

 vagina bulbosa (vb). The latter, after proceeding a short distance 

 anteriorly from the junction point of the unpaired uterus, bends 

 interiorly, then to pursue an obliquely postero-ventral course 

 surrounded by the shell glands (sg) and along the postero-dorsal 

 side of cirrus cavity. In its inferior parts the shell-gland passage 

 is much widened and presents an irregular contour. It opens 

 into the large vagina bulbosa at the anterior end. The bulbosa is 

 provided with a strongly muscular sheath, the wall of its cavity 

 thrown into much folds. Female aperture situated in the penulti- 

 mate fifth of body. 



The species seems to be nearly allied to Planoctru, kawaiiensis 

 described by Heath (1907) from the Sandwich Islands, but may 

 be distinguished from it by the colouration of body and by the 

 entire absence of chitinous penial hooks. 



In 1907 Meixneb ('07b) described a worm from the Gulf of 

 Tadjourrah, which he identified with Stylochus reticulatus Stimpson 

 though with some doubt. To us it appears, judging from the 

 description and figures given by him, the worm in question is 

 certainly a Styloclius but probably represents a distinct species. It 

 should not therefore be confounded with the Misa Id form described 

 above. 



lO. Plunocera purpurea, n. sp. 

 (PI. I., fig. 7. — Textfig. 23). 



Numerous specimens of this apparently new Species have been 

 obtained at the low-water mark in the neighbourhood of Misaki as 

 well as of Shirahama in Pro v. Awa. 



Body oval, reaching 20 mm. in length and 13 mm. in breadth. 

 Dorsal surface of a dark purplish colour, darker in the median parts; 

 main gut and its dendritic branches obscurely showing themselves 

 in a brownish colour. Immediately behind main gut and at about 

 the hind end of the third quarter of body, a pale unpigmented 

 space marks the position of genital organs; in mature individuals, 

 uteri discernible in a reddish colour on either side of that space, as 

 in the preceding species. 



