NO. 9 MARINE INVERTEBRATES, ALASKA — MacGINITIE I77 



by living snails, are often overgrown with bryozoan colonies and 

 barnacles. 



The genus Buccinuni is well represented at Point Barrow, both as 

 to number of species and number of individuals. Individuals within 

 a species vary tremendously, making identifications exceedingly diffi- 

 cult. It is of interest to note that although there are 14 species of 

 Buccinum in Greenland waters and at least 9 or 10 species at Point 

 Barrow, only 3 species, B. glaciale, B. tenue, and B. ciliatum, are 

 common to both places. 



Both large and small masses of egg capsules of Buccinmn were 

 dredged and were picked up on shore. Time did not permit attempt- 

 ing to ascribe these masses to their respective species. 



The most abundant species of Buccinum at Point Barrow were 

 B. plectrum, B. glaciale, B. tenue, and B. angulosum in its several 

 varieties. The first three species came largely from the rubble zone 

 down to 522 feet, with two tenue from baited traps at 64 and 80 feet, 

 and one plectrum from a baited trap at 64 feet (See "Trapping 

 Through the Ice"). B. angulosum was obtained chiefly by means of 

 traps through the ice. The majority of the B. polar e collected were 

 also obtained by means of traps. Two live specimens of B. fringillum 

 Dall, formerly known only from 54 feet from Nunivak Island, were 

 dredged at 453 feet. 



A number of specimens of Boreotrophon that could be ascribed to 

 clathratus (Linnaeus), not hitherto reported from the Pacific side of 

 the Arctic, were taken from 125 to 341 feet. Several other species 

 were common in hauls from 80 to 741 feet. Two tgg capsules of 

 Boreotrophon, containing two embryos each, were taken on August 

 30, 1948. 



Three species of Trichotropis — T. bicarinafa (Sowerby), T. bore- 

 alis, and T. kroyeri Philippi — were taken sparingly in the rubble zone. 

 A group of three egg capsules, possibly of T. bicarinata, with 13, 14, 

 and 24 embryo snails, respectively, were taken on September i, 1949, 

 at 328 feet. 



Three specimens of the rare Aquilonaria turneri Dall (only six 

 other specimens known) were taken at 477, 453, and 151 feet. 



Piliscus commodus (Middendorfif) was fairly common from 120 

 to 543 feet, 39 coming from a haul on October 14, 1949, at 175 feet. 

 Crepidiila grandis Middendorfif was also found from 120 to 453 feet, 

 but sparingly, and the specimens did not live up to their name, for 

 the largest shell was only 32 mm. in length. 



Natica clausa Broderip and Sowerby is one of the more abundant 

 gastropods at Point Barrow. Nearly 100 specimens, including about 



