PLATE XXXII. 



PLIOtKXK I'FX'TKXS. 



[Hnless Dtlu-rwise stati-d all figures art- jijtpnixinuitcly iiMtural size.] 



Page. 



Fici. 1. TWten {Perteu) xtearmilVM. IT. S. N. M. 148008 100 



Exterior of rii;ht valve; altitude 87 mm. San Diego fciruiatiim ( I'lioceiie) , Pacilie I'.eacb, 

 San Diego County, Cal. (M. H. ) 



Fk;. 1(1. Same s|>e<-iinen as tiir. 1 - 100 



Exterior of left valve. (.M. B. ) 



208 



