ACORN WORMS 



53 



These animals, rarely found exposed on the surface, are usually 

 obtained by digging or turning over rocks. Some species may be 

 located by the coiled casting of sand thrown up in a cone at one 

 end of the burrow, but many are encountered only by chance 

 when digging in appropriate situations. They usually break and 

 are obtained as pieces. These fragments are valuable and should 

 not be discarded in the hope of finding whole specimens. But 



Fig. 37. — An acorn worm. 



if one fragment is recognized as a balanoglossid, efforts to find 

 others should be made. Balanoglossids should be carried back 

 to the working quarters in containers separate from any other 

 material collected at the same time, as they often give off great 

 quantities of mucus. 



They should be preserved within a few hours of capture. All 

 serious study of balanoglossids depends on their subsequent 

 cutting into thin sections, so that careful preservation is necessary. 

 If possible, place them in a tray of clean sea water and allow 

 evacuation of sand from the gut for an hour or so. Then slip 



