224 



American Seas hells 



y^ inch in length, rather thin, but quite strong; surface glossy. 7 whorls. 

 Suture well-impressed. Whorls in spire and upper third of body whorl with 

 about 15 obliquely slanting, strong, rounded, axial ribs. Numerous spiral, 

 incised lines are strongest on the base of the body whorl. Lower columella 

 area with a small shield. Outer lip thickened within by about a dozen small 

 white teeth. Color pinkish gray with indistinct motthngs of orange-brown. 

 A common littoral to shallow-water species. 



Figure 50. Small whelks of the Pacific coast, a, Amphissa versicolor Dall; b, A. 

 Columbiana Dall; c, A. undata Cpr.; d, Searlesia dira Reeve. All X3. 



Amphissa columbiana Dall 



Alaska to San Pedro, California. 



Columbian Amphissa 



Figure 50b 



I inch in length, similar to versicolor, but characterized by its large size, 

 numerous, weak, vertical, axial ribs (20 to 24 on the next to the last whorl, 

 and missing on the last part of the last whorl), and by the low, rounded varix 

 behind the outer lip. Color yellow-brown with indistinct mauve mottlings. 

 Periostracum thin, yellowish brown. Moderately common in shallow water 

 from Oregon to Alaska. 



Amphissa undata Carpenter Carpenter's Amphissa 



Figure 50c 

 Monterey, California, to Lower California. 



Vs to y2 inch in length, similar to versicolor, especially in color, but with 



