62 



BULLETIN 76, UNITED STATES NATIONAL MUSEUM 

 Specimen* of Ltptasterias polaris borealis examined 



LEPTASTERIAS POLARIS ACERVATA (Stimpson) 



30, Figures 3-5; Plate 31; Plate 32, Figures 1, 2; Plate 33, Figure 7; Plate 36, Figures 2, 3; 



Plates 37-40 



Astirias acervala Stimpson, Proc. Boston Soc. Nat. Hist., vol. 8, 1862, p. 271. Bell, Proc. 



Zool. Soc. London, 1881, p. 494. — Murdoch, Rep. Int. Polar Exp. Point Barrow, 1885, 



p. 158. — Ludwig, Zool. Jahrb. 1886, p. 287. — Sladen, Challenger Asteroidea, 1889, 



p. SIS. — Vi:hhill, Shallow-water Starfishes, 1914, p. 107, pi. 27, figs. 1, 2 (not pi. 106, 



fig. 3 = dispar.). 

 A. imlaris var. acervala Verrill, Ainer. Nat., vol. 43, 1909, p. 545. 

 Aeterias polythelia Verrill, Amer. Journ. Sci., vol. 28, 1909, p. 68; 1914, p. 104, pi. 55, figs. 



1, 2; pi. 70, fig. 8; pi. 72, fig. 2; pi. 84, figs 3, 4; pi. 79, figs. l-2o.— A. H. Clark. Rep. 



Canadian Arctic Exp., 1913-1918, 1920, p. 8c (Port Clarence). 

 Asterias philippii Bell, Proc. Zool. Soc, 1881, p. 511, pi. 47, figs. 1, la. See Fisher, Ann. 



and Mag. Nat. Hist. Ser. 9, vol. 18, 1926, p. 198. 

 Stenasterins macropora, A. II. Clark, Rep. Canadian Arctic Exp. 1920, p. 9c (Port Clarence). 

 borealis, A. II. Clark, Rep. Canadian Arctic Exp., 1920, p. 8c (E. of Cape 



Lisburne). 

 Leplasterias polaris acervala Fisher, Ann. and Mag. Nat. Hist., ser. 9, vol. 12, 1923, p. 599. 



This name is intended to designate the polymorphic representative of L. polaris 

 which inhabits Bering Sea and adjacent parts of the Arctic Ocean and north Pacific. 

 A "composite diagnosis" covering all of its phases is of no practical value since the 

 race does not exisl as a composite but in the guise of three major formae which inter- 

 grade. These formae arc: aphdonota Fisher, acervata Stimpson, and polyfhela Verrill. 



The race as a whole differs from L. polaris polaris of West Greenland waters in 

 this accentuated polymorphism (one phase of which, polyihela, is not represented 

 east of Alaska ) and in the larger size of the straight pedicellariae. 



