The Occurrence of Polygordius Adult 

 at Laguna Beach 



William A. Hilton 



For a number of years now we have taken Branchiostoma just 

 off shore in rather coarse sand, but it was not until the summer of 

 1920 that we began to look for archiannelids. A few doubtful 

 specimens were obtained from sea weeds but nothing that we could 

 be sure were the animals sought. We never thought to search the 

 sand in which Branchiostoma was taken until after reading in the 

 monograph on Polygordiw^ how the creatures were obtained near 

 Naples. With the hint that these animals were sometimes asso- 

 ciated we examined with great care some hundreds of pounds of 

 coarse sand in which some few Branchiostoma had been found and 

 from this two specimens were obtained, one dead and one living. 

 These were without question of the genus Pnlygordius although to 

 make the matter more certain sections were made. Although the 

 genus is certain, the species remains undetermined because the 

 caudal ends of the animals were not perfect. 



The living specimen was very active. At first it was taken to 

 be a rather long round worm but the characteristic antennae at the 

 head region caused it to receive more attention. 



So far as I can tell, this is the first record of the adult of Poyl- 

 gordius being found in North America in its natural environment 

 at least, for some have been reared from the larva! forms at Woods 

 Hole. 



(Coyitrihvtion from the Zologiral Laboratory of Pomona Col- 

 lege.) 



