BUCCINIDAE 225 



a much higher spire, stronger axial ribs, and much stronger, more acute, spiral 

 cords. Moderately common from 25 to 265 fathoms. 



Amphissa bicolor Dall Two-tinted Amphissa 



Farralon Islands, to San Diego, California. 



% to % inch in length, similar to versicolor, but thinner-shelled, usually 

 with fewer ribs, glossy-white in color, but covered with a pale-straw peri- 

 ostracum, and without the small teeth inside the outer lip. Dredged com- 

 monly from 40 to 330 fathoms. 



Favnly BUCCINIDAE 

 Genus Buccinum Linne 1758 



Buccinwn undatum Linne Common Northern Buccinum 



Arctic Seas^to New Jersey. Europe. 



2 to 4 inches in length, solid, chalky gray to yellowish with a moderately 

 thick, gray periostracum. Axial ribs 9 to 18 per whorl, low, extending ^ 

 to V2 way down the whorl. Spiral cords small, usually about 5 to 8 between 

 sutures. Outer lip slightly or well sinuate and somewhat flaring. Aperture 

 and parietal wall enamel-white. Anterior canal short. 1V2 nuclear whorls 

 fairly large, smooth and translucent-white. Operculum oval, concentric, 

 chitinous, and light yellow-brown. A very variable shell which sometimes 

 lacks the axial ribs but may have numerous spiral threads. Common just off- 

 shore to several fathoms in cold water. 



Buccinum tenue Gray Silky Buccinum 



Plate 24U 



Arctic Seas to Washington State. Arctic Seas to the Gulf of Maine. 



1V2 to 1V2 inches in length; aperture 'V2 the length of the shell. Outer 

 lip slightly sinuate, thin and slightly flaring. Axial ribs small, numerous, inter- 

 twining and extending from suture to suture. Spiral sculpture of microscopic, 

 beaded threads giving a silky appearance. Color light-brown. Common off- 

 shore. Compare with plectrum Stimpson. 



Buccinum plectrum Stimpson Plectrum Buccinum 



Figure 51a 



Arctic Seas to Puget Sound. Arctic Seas to the Gulf of St. Lawrence. 



2 to 3 inches in length; aperture a little more than % the entire length 

 of the shell. Outer lip strongly sinuate, thickened and flaring. Axial ribs 



