NO. 9 MARINE INVERTEBRATES, ALASKA — MacGINITIE I35 



A method that proved successful with a polynoid from southern Cali- 

 fornia that always broke itself in two when handled was then tried : 

 the worm was laid on a paper towel until it became partly dry and 

 inactive, when it could be placed in preservative without a casualty. 

 A. sarsi could not be managed in this manner. Varying strengths of 

 both hot and cold formalin and alcohol were tried separately and in 

 combination, as well as in combination with other chemicals, without 

 success. A quick flooding with boiling formalin was the most satis- 

 factory method but this shrank the specimens considerably. Other 

 methods, such as anesthetizing before placing the worm in preserva- 

 tive (provided the anesthetization was successful in the first place), 

 sometimes gave promise of being successful. The elytra would stay 

 in place for several hours — but then all of them would drop ofif. 



As a last resort it was decided to try anesthetizing these worms 

 with something to which they were already accustomed — cold. They 

 were placed in a tray with barely enough water to cover them and 

 put in the freezing compartment of a refrigerator. When ice formed, 

 it was thawed slightly and the worms quickly placed in preservative. 

 If only the water froze, the worm would be as lively as ever when 

 the ice thawed, but if the worm became slightly frozen it could be 

 placed in preservative without danger of the elytra's shedding. An 

 attempt was made not to freeze the worm to the extent of damaging 

 the tissues. This method of anesthetizing polynoids proved the most 

 satisfactory one, even with those species that were less sensitive. 



Without much doubt, Antinoe sarsi is commensal with the echiuroid 

 worm Echiurus echiurus alaskanus. Both were washed ashore in 

 large numbers during storms. The polynoid looks like a commensal 

 form and it closely resembles Hespcronoc adventor (Skogsberg), 

 which is commensal with the echiuroid worm Urechis caupo off the 

 coast of California (MacGinitie, 1935). The writer often wished it 

 were possible to dig the animals out of their burrows as easily as they 

 can be dug from a mud flat. The copepod Herpyllobius arcticus was 

 found on a specimen of Antinoe sarsi collected on August 21, 1949 — 

 a new host for this parasite. 



The bright tan-colored polynoid Arcteohia antic ostiensis (Mcin- 

 tosh) was taken from 148 to 741 feet. It is no doubt commensal 

 with one of the terebellids, possibly Pista maculata. It is new to 

 Arctic Alaska. 



The large (60 mm. long by 23 mm. wide) Eunoe nodosa (Sars), 

 undoubtedly a free-living form, was fairly common from depths of 

 no to 522 feet. In life it is pale green and dull red, with reddish- 

 brown tubercles on the scales. Like Antinoe sarsi, this species would 



