-i —a 



The Development of Polymorphites jitpiter. Fig. 1, adult (30 mm.) ; Fig. 2, 

 arched venter (at diam. 8 mm.); Fig. 3, early chambers, x 72 ; 

 Figs. 4-6, successive stages (diam. -7, -75, 1 '2 mm. ) ; Fig. 7, costate 

 stage (2 - 8mm.) ; Fig. 8 (8mm.) ; Fig. 9, protoconch, x 63. 



