inhabiting the ^yean Sea. 245 



bitat, the sea-bottom seems studded with dark brown sea-ur- 

 chins ; but, on touching these supposed sea-eggs, they in- 

 stantly shrink into the sand. These are expanded tufts of 

 branchiae which adorn the head of the animal. It lives in a 

 tough gelatinous case of its own construction, which case is 

 smooth within and without, and of considerable length and 

 thickness. The inhabitant is quite free within, and moves up 

 and down with facility ; but the hinder part of the case, which 

 tapers into an acute tail, is solid for some way, and probably 

 is so in consequence of the creature tilling it up as it grows 

 older and larger. The worm has a highly extensile body, 

 composed of above 140 rings, blunt anteriorly and tapering 

 posteriorly. The rings are of a reddish brown hue, the belts 

 between paler, and there are two very narrow pale lines on 

 the margins of each. They are very contractile. Each of 

 them is furnished with a minute tuft of bristles on each side, 

 serving as feet. There is no well-defined head, nor eyes, nor 

 tentacula ; but there is a broader and more prominent whitish 

 band at the junction of the branchial funnel with the body 

 than elsewhere. The funnel consists of two fasciculi of long 

 setose filaments, about twenty-eight in each bundle ; each of 

 these filaments (which are all webbed together, saving near 

 their extremities,) is furnished with a comb of long finer fila- 

 ments on the inner margin, which project into the interior of 

 the funnel, and define its shape very prettily. Up and down 

 the funnel currents of water may be seen flowing with great 

 rapidity. These are caused by the cilia which cover the se- 

 condary filaments, and which are of considerable size. The 

 secondary filaments are notched at regular intervals, and are 

 very flexible, twisting about like worms when separated from 

 their origin. 



In the absence of works of reference, though I believe both 

 these forms to be new, generically as well as specifically, I have 

 abstained from naming them at present. 



DESCRIPTION OF PLATE VI 11. 



/fcthiia. 

 Fiff, 1, 2, 3. Attitudes of the animal freed from the tube. 

 Fiff. 4. The animal in its tube. 

 Fi(/. 5. The animal leaving its membranous case. 



Jlntiellde. 

 Fig. G. The animal within its tube. 

 Fig. 7. Head and branchi;e expanded, protruded from the tube in the 



sand. 

 Fig, 8. Animal out of the tube extending itself. 

 Fig. 9. Animal contracted. 

 Fig. 10. Segments magnified, showing the feet. 

 Fig. II. One of the pinnated branchite. 

 Fig. 12. A pinna magnified, showing the cilia and llie joints. 



