CHAMA, CARDIUM AND VENUS 73 
Columbia River; var. laciniata, Cpr., a southern 
form with a beautiful network covering, and many 
small prickles, (Tapes lacineata). Var. ruderata, 
Desh., has distinct, concentric ridges, sometimes 
larger than the ribs; var. orbella, Cpr., includes 
swollen and irregular specimens, living in holes 
in the rocks, while most common specimens live in 
coarse gravel and grow to regular shapes. 
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AP ws 
Hi 
Fig. 39,x ¢ 
Paphia tenérrima, Cpr., the Finest Carpet-shell, 
(Tapes t.) is a rather rare species, very distinct, 
and very pleasing in appearance. An inside view 
of a left-hand valve is given in Figure 59, to which 
reference has been already made on page 17. The 
outside of the shell is marked with many low, con- 
centric ridges, and innumerable, minute ribs. The 
valves are thin and the color is brownish gray. 
