E 



XPLANATION OF 



Figs. 1-6. — Buccininn glaciale Linnaeus: 1, from l.SO feet, showing characteristics close to 

 those of typical B. glaciale; 2, from 522 feet, showing one faint carina, rounded shoulder, 

 and fairl\- weak axial folds; 3, from 184 feet, showing stronger axial folds, one carina, 

 a slight keel at the shoulder, and gradually expanding whorls; 4, from 125 feet, the most 

 common form at Point Barrow, showing axial folds, one strong carina, a keel at the 

 shoulder, a base flatter than in the preceding specimens, and more rapidly expanding 

 whorls; 5, from 80 feet (Apr. 12, 1950), characterized by moderate axial folds, a long 

 slender spire and flat whorls; 6, from 125 feet, characterized by a long, very slender 

 spire, a short aperture, a mere suggestion of a carina, and rounded shoulder and base. 



Figs. 7, 10, 13. — Buccinum glaciale var. niorchiaiium Dunker: 7, an immature specimen 

 from 213 feet exhibiting a strong shoulder; 10, a young specimen from 522 feet showing 

 a faint carina and a weak shoulder; 13, a mature specimen from 453 feet with 2 carinae 

 on the body whorl and a moderate shoulder. 



Figs. 8, 9. — Buccinum tenue Gray: 8, from 80 feet (Apr. 18, 1950); 9, specimen with its 

 operculum, from 110 feet (Sept. 8, 1948). The shells are usually much thinner and the 

 spiral sculpturing much fainter than in B. plectrum; the interrupted nature of the axial 

 fold gives them a wavy appearance. 



Figs. 11, 12. — Buccinum plectrum Stimpson: 11, from 125 feet; 12, from 522 feet. Typical 

 specimens. 



Magnification: All about same size. 



