THE DEVELOPMENT OF SCAPHITES 



643 



Fig. 2. — 1, Scaphites nodosus var. quadrangularis; X7. 2 and 3, Desmoceras 

 hoffmanii; Xio; 4 mm ; showing constrictions and development of sutures; 3 repre- 

 sents a much younger stage. 4, 5. condoni and inermis protoconch showing caecum. 

 5, Side view of protoconch; X30. 6, Same at D. of 8 mm ; X30. 7, Same at 8 mm ; 

 X30. 8, Same at 4mm; X8. 9, Same at end view; 4mm; Xn. io ; Cross-section 

 of S. inermis (half whorl missing). 11, Cross-section of S. condoni; Xj. 12, Adult 

 of 5. condoni. 14, Larval coil of Baculites chicoensis. 



