THE GEPHYREA OF JAPAN. 5 



two slender wavy bauds {sx), developed across the points of origin 

 of the retractor muscles (vm). 



The present species agrees in some points with Fhascohsoma 

 semperi Sel. & De Man, as described by Selenka (28), but it 

 can be readily distinguished from that species by the characteristic 

 dermal papillœ. The same distinction may be pointed out as 

 obtaining between the present species and Fhascolosoma fimbriatum 

 Sluiïer (37). 



Habitat : The species is one of tlie commonest Sipunculoids 

 met with in the vicinity of the Misaki Marine Laboratory ; it is 

 also common along the coasts of the Tokyo Bay and of the 

 Inland Sea. It lives in shallow muddy bottom, especially in small 

 inlets into which fresh-water finds egress. 



FHASCOLOSOMA JAPONICUM, n. sp. 



(Figs. 2, 28 & 29). 



The length of the body proper is about 5 cm. on an average, 

 the introvert being about as long as two-thirds of the body proper 

 (Fig. 2) ; the two regions pass over into each other without a 

 distinct demarkation. The maximum width of the body proper 

 is about 7 mm. The body-wall is thin and of a brownish yellow 

 color, of a deeper brown in male worms than in female. To the 

 naked eye the skin-surface appears quite smooth, but under certain 

 magnification there are seen numerous skin-bodies of elliptical 

 shape, thickly distributed (Fig. 28). These bodies are flat, not 

 covered with chitinous plates, and are somewhat transparent ; a 



