2Ó0 



I. IKEDA. 



situated at the ordinary position, and is not guarded by the caudal 

 spines. 



The proboscis is exceedingly slender as compared with the body 

 proper. Since the proboscis is a very contractile organ, it would have 

 been much longer when alive than it is now. The organ has a deep 

 longitudinal groove along its ventral side, giving it a tubular appearance. 

 The tip of the proboscis is somewhat truncated. The ventral groove abrupt- 

 ly closes towards the mouth, forming a large oral funnel. The proboscis 

 is colorless and is covered with fine wrinkles. 



The general aspect of the viscera in situ is shown in fig. 2, which 

 represents the animal opened along the mid-dorsal line. The alimentary 

 canal is cut across at one place, so as to expose the segmental organ and 

 the blood vessels ; the gonad (oz>) has been accidentally displaced to the 

 right being torn off from the ventral vessel. 



Alimentary canal. — The alimentary canal is held in definite course by 

 numerous fine threads of muscles arising from the integument. Various 

 parts of the intestinal tract are very poorly demarkated in the alcoholic 

 specimen. The collateral intestine (ci) is distinctly developed along the 

 median ventral line of the mid-gut ; both its extremities are marked in the 

 figure with t. Of these, the anterior end nearly coincides with the 

 posterior border of the ring-like sinus known as the "heart" (ht). The 

 mid-gut and the collateral intestine taken together make up about one 

 third of the length of the entire canal. The hind-gut is relatively long, 

 occupying about one fifth of the intestine. As is the case with many 

 other Echiuroids, it is distinguishable from.' the mid-gut by the presence 

 of the ciliary groove instead of the collateral intestine. 



Anal glands. — To the terminal portion of the hind-gut near the anus 

 are appended the anal glands, two relatively short (about 5 mm. long) and 

 slender tubes bearing numerous and long-stalked funnels (fig. 2, ag.). 

 They are destitute of any attaching muscles, the free ends floating in the 

 coelom. It is somewhat dendritic, recalling the same organ of some 



