NO. 9 MARINE INVERTEBRATES, ALASKA — MacGINITIE i8i 



test, making the surface gritty. It occurred in every haul from no 

 to 741 feet (where it was growing on the tubes of Pista maculata). 

 It grew on bryozoans, on barnacles, on stones, and on the holdfasts 

 and stems of hydroids and bryozoans. It is new to Arctic Alaska. 



Three specimens of Ascidia callosa Stimpson were collected from 

 stones and bryozoans at 125 feet. Cream-colored organs showed 

 through the transparent or translucent tan tunics. It is new to Arctic 

 Alaska. 



Chelyosoma macleayanum Broderip and Sowerby was common in 

 hauls from 120 to 477 feet, usually attached to rocks but sometimes 

 growing on other tunicates, such as Styela. Four individuals taken 

 on October 14, 1949, had immature ovaries but well-developed testes. 

 This species is new to Arctic Alaska. 



Order STOLIDOBRANCHIATA 



Dendrodoa pulchella (Verrill) was common in all hauls from no 

 to 140 feet and also occurred at Eluitkak Pass. It was usually at- 

 tached to stones but also grew on other tunicates such as Styela and 

 Boltenia echinata. The tunic varied from flesh color to dirty flesh to 

 muddy tan. It is new to Point Barrow. 



Dendrodoa grossularia (van Beneden) was common on rocks from 

 depths of 125 to 216 feet. Most specimens are characterized by a 

 bluish tint around the siphonal openings. An individual taken on 

 October 6, 1949, was filled with eggs 0.25 mm. in diameter. It is 

 new to Arctic Alaska. 



One of the commonest of the simple ascidians was Styela rustica 

 macrenteron Ritter, which was found at Eluitkak Pass and was abun- 

 dant in hauls from 120 to 453 feet. Bryozoans, young barnacles, and 

 Didemnitrn alhidum were often found growing on its cream-colored 

 tunic. Foraminifers often nestle in the tunic, forming depressions so 

 deep that the testes scarcely project above the surface of the tunic. 

 Although numerous individuals were opened and examined for cope- 

 pods, none was found. Individuals from 35 to 45 mm. in height that 

 were examined on October 14, 1949, had immature or developing 

 testes and well-developed ovaries. Specimens from 7 to 8 mm. high 

 were found from the first of August to the middle of October, This 

 species is new to Point Barrow. 



Styela coriacea (Alder and Hancock), less abundant than the above 

 species, was found at Eluitkak Pass and in all hauls from no to 140 

 feet. It may be present in unidentified material from deeper hauls. 

 It is new to Point Barrow. 



