80 



WEST COAST SHELLS 



Fig. 54 



but they have received, however, 

 several times three names. Fig- 

 ure 54 gives an end view of Chi- 

 one succincta^ Val., the Banded 

 Chione. The cordate lunule is a 

 prominent mark, while on the 

 other side of the beaks is the long 

 and deep escutcheon. Numerous 

 ribs radiate out from the umbo, 

 but those in the middle generally 

 become flattened towards the edge of the shell. The 

 concentric ridges, as shown in the picture, run around 

 the shell somewhat like hoops around a barrel. The 

 interior of the shell is white, while the outside is a 

 dingy yellow. 



Chione undatella^ Sby., the Wavy Chione, is a 

 species which varies considerably, but it can usually 

 be told readily by the great number of concentric 

 lamellae, which are closer together as they come near 

 the edge of the shell, almost completely concealing 

 the ribs. The valves are inflated, thick and heavy. 

 Sometimes the interior is purple around the pallial 

 sinus. These shells, which are seldom over two 

 inches long, are found abundantly in southern Cali- 

 fornia. 



Chione fluctifraga^ Sby., the Smooth Chione, is 

 about the same size as the others. There is no dis- 

 tinct lunule, as in the other kinds, and the rib struc- 

 ture in the middle of the disk becomes fainter with 

 age, till it sometimes almost disappears near the edge 

 of the shell. Internally the valves are more or less 

 purple. All three of these species have strong, heavy 



