MARINE UNIVALVES 



161 



Fig. 147 



except on the first few whorls. The color is light 

 brown, but the aperture is white. My largest speci- 

 men measures 23 mm. in length. 



Nassa per ping u is ^ Gld., the Fat Nassa, 

 Figure 147, has the prettiest shell of all 

 of our species of Nassa. The cut does 

 scant justice to a good specimen, though 

 it shows that the shell is finely checked, 

 being cut into a multitude of little 

 squares. The whorls are plump and fat, 

 the shell rather thin, the color whitish or 

 light brown, with sometimes a dash of orange in- 

 side, and a spiral stripe of chestnut running around 

 the middle of each whorl. The outer lip is sharp 

 and thin. Most specimens are rather smaller than 

 the figure. 



Nassa mendica^ Gld., the Lean Nassa, 

 Figure 148, is a variable species, having a 

 more slender shell than the last. The sur- 

 face is marked with numerous fine, spiral 

 lines, crossed by ridgy varices. The color 

 is light brown, with a white peristome. It 

 occurs all along the coast from Puget Sound 

 to San Diego. There is a variety, named 

 var. cooperi^ Fbs., which has for sculpturing a few 

 strong transverse ribs and small spiral lines. Fig- 

 ure 148 resembles this variety. 



Nassa calif orniana^ Conr., the California Nassa, is 

 a rare species, sometimes found alive on the coast of 

 the southern half of California, particularly about 

 San Pedro. It is as large as Nassa fossata^ and it has 

 the general form and sculpturing of Nassa perpin- 



Fig. 148 



