Chaetopterus Variopedatus. 501 



can move about in the glass tube with freedom. The rapid vibration 

 of the palettes does not have the tendency of ''washing the animal 

 backwards" in spite of the fact that the uncinal plates can not "pene- 

 trate the walls" of this artificial tube. 



Feeding and the Nature of the Food. — The water which the seden- 

 tary annelid causes to pass through its tube bears a large amount 

 of organic matter, and the abundance of the fseces attests to the fact 

 that a large amount of it is strained from the water as it passes 

 over the regions that perform this function. 



The faeces, which in an average-sized worm are pretty uniformly 

 six to eight millimeters long and one millimeter in diameter, con- 

 tain the tests of many of the diatoms which Dr. Caswell Grave 

 ('04) has found to serve as the food of oysters in the same waters. 

 They are principally Melosira, two species, Pleurosigma, Ewpo- 

 disciis, in addition to other forms which I have not determined. 

 There were also shells of molluscan embryos, skeletons of copepods 

 and young Crustacea of several species, but grains of sand are rarely 

 found. It may be true that other embryos have served as food for 

 Chsetopterus, but there is no trace in the fseces because of their com- 

 plete digestion. The presence of eggs of Chsetopterus, in sections of 

 the esophagus, leads me to believe that animal cells, when available, 

 likewise serve as food in these annelids. 



The general ciliary covering of the large buccal funnel, the 

 grooves of the dorsal surface and the accessory feeding organ of the 

 thirteenth segment of the annelid serve as organs for the prehension 

 of food in the absence of such prehensile organs as are common 

 to many other annelids. This may be demonstrated by the applica- 

 tion of finely divided carmine in sea-water to the ciliary grooves. 

 When the carmine is dropped into the grooves of both aliform nota- 

 podia of the twelfth segment the small particles are swept down- 

 wards toward their bases. Here they pass from each side directly 

 into the ciliary groove of the mid-dorsal line and are swept forwards 

 to its anterior extremity which is directly back of the .dorsal lip 

 of the buccal funnel. They are then dropped into the mouth. To 

 this extent my observations agree with those of Laffuie. 



The particles of carmine which have traversed the ciliary groove 



