482 Howard Edwin Enders. 



either covered with a thick growth of diatoms or continually exposed 

 to currents of water heavily charged with diatoms. It is here found 

 living within its broadly U-shaped parchment tubes in nearly every 

 portion of the harbor wherever the sand-flats are formed in the quieter 

 waters. It is less abundant on the tide-swept flats of coarse sand, 

 and so far as I know it has never been taken during any of the 

 dredgings in the channels ; this may be due to the rapid changes in 

 the shifting channels within the large but shallow harbor. 



The shallow water in which the worms live here is in marked 

 contrast with their position along the coast of France where Joyeux- 

 Laffuie procured the animals either by dredgings in water ten meters 

 deep or from among the masses of tubes cast upon the shore after the 

 great storms from the north and northwest. Along the coast of 

 Erance the annelids are confined to the deeper water on account of 

 the shifting sands of the shore, but on this portion of the American 

 coast an abundance of material may be collected wdth a spade at a 

 single low tide. At Beaufort, during three summers, I found only 

 two mutilated tubes cast upon the shore outside of the harbor after 

 heavy storms. It is rather more likely that these tubes were carried 

 out from the harbor than that they w^ere torn up from the deeper 

 regions lieyond the harbor. 



The presence of Chfetopterus may be recognized at low tide by the 

 two extremities of the broadly U-shaped tubes that usually protrude 

 several centimeters above the level of the shoal (Fig. 1). The ex- 

 tremities of some tubes are concealed by ascidians, colonies of 

 bryozoans, or of hydroids, attached to them so that it may be difficult 

 to detect their circular whitish openings within the cluster of attached 

 animals. Usually two tubes are visible above the surface of the sand, 

 but three are frequently found, as I shall show later (Fig. 2). After 

 both extremities, which are from fifteen to fifty centimeters apart, 

 have been located, it is a vei*y simple matter to remove the tube by 

 simply raising it with a spade and then gently freeing it from the 

 wet sand. Where the three tubes are present the third may be over- 

 looked and the animal may be mutilated in removal. 



The animals may be removed from the tubes in perfect condition 

 by ripping them lengthwise Avith one's fingers. The habit of the 



