PLATE 11. 



Fig. 1. — Astacus klamathensis Stimpson. a'. Portland, Or. U. S. N. M., slightly enlarged. Showing 



the chelipeds of normal shape. 

 Fig. 2. — Asiacus klninathensis Stimpson. cT . Portland, Or. U. S. N. M., slightly reduced. Showing 



the abnoimal, atavistic form of the regenerated claw of the left side. 



